X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fguestfs.c;h=0e4cb73bc2a259c395b2a2739299693499c673f8;hp=a5b3ae42772c6690b23be0118bc4ec24ff128439;hb=8700a55d52f25f60f01ef1b67cff6d5c0071700b;hpb=09c16b5da0ec982bfffe654a55abd637a3335c95 diff --git a/src/guestfs.c b/src/guestfs.c index a5b3ae4..0e4cb73 100644 --- a/src/guestfs.c +++ b/src/guestfs.c @@ -1,5 +1,5 @@ /* libguestfs - * Copyright (C) 2009 Red Hat Inc. + * Copyright (C) 2009-2010 Red Hat Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -23,11 +23,20 @@ #include #include #include +#include +#include +#include #include -#include #include #include #include +#include +#include +#include +#include + +#include +#include #ifdef HAVE_ERRNO_H #include @@ -49,82 +58,280 @@ #include #endif +#include +#include + +#include "c-ctype.h" +#include "glthread/lock.h" +#include "ignore-value.h" + #include "guestfs.h" +#include "guestfs-internal.h" +#include "guestfs-internal-actions.h" +#include "guestfs_protocol.h" + +#ifdef HAVE_GETTEXT +#include "gettext.h" +#define _(str) dgettext(PACKAGE, (str)) +//#define N_(str) dgettext(PACKAGE, (str)) +#else +#define _(str) str +//#define N_(str) str +#endif + +#define error guestfs_error +#define perrorf guestfs_perrorf +#define safe_malloc guestfs_safe_malloc +#define safe_realloc guestfs_safe_realloc +#define safe_strdup guestfs_safe_strdup +//#define safe_memdup guestfs_safe_memdup + +#ifdef __linux__ +#define CAN_CHECK_PEER_EUID 1 +#else +#define CAN_CHECK_PEER_EUID 0 +#endif + +static void default_error_cb (guestfs_h *g, void *data, const char *msg); +static int send_to_daemon (guestfs_h *g, const void *v_buf, size_t n); +static int recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn); +static int accept_from_daemon (guestfs_h *g); +static int check_peer_euid (guestfs_h *g, int sock, uid_t *rtn); +static void close_handles (void); +static int qemu_supports (guestfs_h *g, const char *option); + +#define UNIX_PATH_MAX 108 + +#ifndef MAX +#define MAX(a,b) ((a)>(b)?(a):(b)) +#endif -static int error (guestfs_h *g, const char *fs, ...); -static int perrorf (guestfs_h *g, const char *fs, ...); -static void *safe_malloc (guestfs_h *g, int nbytes); -static void *safe_realloc (guestfs_h *g, void *ptr, int nbytes); -static char *safe_strdup (guestfs_h *g, const char *str); +#ifdef __APPLE__ +#define xdr_uint32_t xdr_u_int32_t +#endif -#define VMCHANNEL_PORT 6666 -#define VMCHANNEL_ADDR "10.0.2.4" +/* Network configuration of the appliance. Note these addresses are + * only meaningful within the context of the running appliance. QEMU + * translates network connections to these magic addresses into + * userspace calls on the host (eg. connect(2)). qemu-doc has a nice + * diagram which is also useful to refer to. + * + * NETWORK: The network. + * + * ROUTER: The address of the "host", ie. this library. + * + * [Note: If you change NETWORK and ROUTER then you also have to + * change the network configuration in appliance/init]. + * + * GUESTFWD_ADDR, GUESTFWD_PORT: The guestfwd feature of qemu + * magically connects this pseudo-address to the guestfwd channel. In + * typical Linux configurations of libguestfs, guestfwd is not + * actually used any more. + */ +#define NETWORK "169.254.0.0/16" +#define ROUTER "169.254.2.2" +#define GUESTFWD_ADDR "169.254.2.4" +#define GUESTFWD_PORT "6666" /* GuestFS handle and connection. */ +enum state { CONFIG, LAUNCHING, READY, BUSY, NO_HANDLE }; + struct guestfs_h { - /* All these socks/pids are -1 if not connected. */ + struct guestfs_h *next; /* Linked list of open handles. */ + + /* State: see the state machine diagram in the man page guestfs(3). */ + enum state state; + + int fd[2]; /* Stdin/stdout of qemu. */ int sock; /* Daemon communications socket. */ - int pid; /* Qemu PID. */ - time_t start_t; /* The time when we started qemu. */ - int daemon_up; /* Received hello message from daemon. */ + pid_t pid; /* Qemu PID. */ + pid_t recoverypid; /* Recovery process PID. */ - char *tmpdir; /* Temporary directory containing logfile - * and socket. Cleaned up unless there is - * an error. - */ + struct timeval launch_t; /* The time that we called guestfs_launch. */ + + char *tmpdir; /* Temporary directory containing socket. */ + + char *qemu_help, *qemu_version; /* Output of qemu -help, qemu -version. */ char **cmdline; /* Qemu command line. */ int cmdline_size; - guestfs_abort_fn abort_fn; - int exit_on_error; int verbose; + int trace; + int autosync; + int direct; + int recovery_proc; + + char *path; /* Path to kernel, initrd. */ + char *qemu; /* Qemu binary. */ + char *append; /* Append to kernel command line. */ + + int memsize; /* Size of RAM (megabytes). */ + + int selinux; /* selinux enabled? */ + + char *last_error; + + /* Callbacks. */ + guestfs_abort_cb abort_cb; + guestfs_error_handler_cb error_cb; + void * error_cb_data; + guestfs_log_message_cb log_message_cb; + void * log_message_cb_data; + guestfs_subprocess_quit_cb subprocess_quit_cb; + void * subprocess_quit_cb_data; + guestfs_launch_done_cb launch_done_cb; + void * launch_done_cb_data; + + int msg_next_serial; }; +gl_lock_define_initialized (static, handles_lock); +static guestfs_h *handles = NULL; +static int atexit_handler_set = 0; + guestfs_h * guestfs_create (void) { guestfs_h *g; + const char *str; g = malloc (sizeof (*g)); if (!g) return NULL; + memset (g, 0, sizeof (*g)); + + g->state = CONFIG; + + g->fd[0] = -1; + g->fd[1] = -1; g->sock = -1; - g->pid = -1; - g->start_t = 0; - g->daemon_up = 0; + g->abort_cb = abort; + g->error_cb = default_error_cb; + g->error_cb_data = NULL; + + g->recovery_proc = 1; - g->tmpdir = NULL; + str = getenv ("LIBGUESTFS_DEBUG"); + g->verbose = str != NULL && STREQ (str, "1"); - g->abort_fn = abort; /* Have to set these before safe_malloc. */ - g->exit_on_error = 0; - g->verbose = getenv ("LIBGUESTFS_VERBOSE") != NULL; + str = getenv ("LIBGUESTFS_TRACE"); + g->trace = str != NULL && STREQ (str, "1"); - g->cmdline = safe_malloc (g, sizeof (char *) * 1); - g->cmdline_size = 1; - g->cmdline[0] = NULL; /* This is chosen by guestfs_launch. */ + str = getenv ("LIBGUESTFS_PATH"); + g->path = str != NULL ? strdup (str) : strdup (GUESTFS_DEFAULT_PATH); + if (!g->path) goto error; + + str = getenv ("LIBGUESTFS_QEMU"); + g->qemu = str != NULL ? strdup (str) : strdup (QEMU); + if (!g->qemu) goto error; + + str = getenv ("LIBGUESTFS_APPEND"); + if (str) { + g->append = strdup (str); + if (!g->append) goto error; + } + + /* Choose a suitable memory size. Previously we tried to choose + * a minimal memory size, but this isn't really necessary since + * recent QEMU and KVM don't do anything nasty like locking + * memory into core any more. Thus we can safely choose a + * large, generous amount of memory, and it'll just get swapped + * on smaller systems. + */ + str = getenv ("LIBGUESTFS_MEMSIZE"); + if (str) { + if (sscanf (str, "%d", &g->memsize) != 1 || g->memsize <= 256) { + fprintf (stderr, "libguestfs: non-numeric or too small value for LIBGUESTFS_MEMSIZE\n"); + goto error; + } + } else + g->memsize = 500; + + /* Start with large serial numbers so they are easy to spot + * inside the protocol. + */ + g->msg_next_serial = 0x00123400; + + /* Link the handles onto a global list. */ + gl_lock_lock (handles_lock); + g->next = handles; + handles = g; + if (!atexit_handler_set) { + atexit (close_handles); + atexit_handler_set = 1; + } + gl_lock_unlock (handles_lock); + + if (g->verbose) + fprintf (stderr, "new guestfs handle %p\n", g); return g; + + error: + free (g->path); + free (g->qemu); + free (g->append); + free (g); + return NULL; } void -guestfs_free (guestfs_h *g) +guestfs_close (guestfs_h *g) { int i; char filename[256]; + guestfs_h *gg; - if (g->pid) guestfs_kill_subprocess (g); + if (g->state == NO_HANDLE) { + /* Not safe to call 'error' here, so ... */ + fprintf (stderr, _("guestfs_close: called twice on the same handle\n")); + return; + } + + if (g->verbose) + fprintf (stderr, "closing guestfs handle %p (state %d)\n", g, g->state); + + /* Try to sync if autosync flag is set. */ + if (g->autosync && g->state == READY) { + guestfs_umount_all (g); + guestfs_sync (g); + } - /* The assumption is that programs calling this have successfully - * used qemu, so delete the logfile and socket directory. + /* Remove any handlers that might be called back before we kill the + * subprocess. */ + g->log_message_cb = NULL; + + if (g->state != CONFIG) + guestfs_kill_subprocess (g); + + /* Close sockets. */ + if (g->fd[0] >= 0) + close (g->fd[0]); + if (g->fd[1] >= 0) + close (g->fd[1]); + if (g->sock >= 0) + close (g->sock); + g->fd[0] = -1; + g->fd[1] = -1; + g->sock = -1; + + /* Wait for subprocess(es) to exit. */ + waitpid (g->pid, NULL, 0); + if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); + + /* Remove tmpfiles. */ if (g->tmpdir) { snprintf (filename, sizeof filename, "%s/sock", g->tmpdir); unlink (filename); - snprintf (filename, sizeof filename, "%s/qemu.log", g->tmpdir); + snprintf (filename, sizeof filename, "%s/initrd", g->tmpdir); + unlink (filename); + + snprintf (filename, sizeof filename, "%s/kernel", g->tmpdir); unlink (filename); rmdir (g->tmpdir); @@ -132,466 +339,2490 @@ guestfs_free (guestfs_h *g) free (g->tmpdir); } - for (i = 0; i < g->cmdline_size; ++i) - free (g->cmdline[i]); - free (g->cmdline); + if (g->cmdline) { + for (i = 0; i < g->cmdline_size; ++i) + free (g->cmdline[i]); + free (g->cmdline); + } + + /* Mark the handle as dead before freeing it. */ + g->state = NO_HANDLE; + gl_lock_lock (handles_lock); + if (handles == g) + handles = g->next; + else { + for (gg = handles; gg->next != g; gg = gg->next) + ; + gg->next = g->next; + } + gl_lock_unlock (handles_lock); + + free (g->last_error); + free (g->path); + free (g->qemu); + free (g->append); + free (g->qemu_help); + free (g->qemu_version); free (g); } -/* Cleanup fds and sockets, assuming the subprocess is dead already. */ +/* Close all open handles (called from atexit(3)). */ static void -cleanup_fds (guestfs_h *g) +close_handles (void) { - if (g->sock >= 0) close (g->sock); - g->sock = -1; + while (handles) guestfs_close (handles); +} + +const char * +guestfs_last_error (guestfs_h *g) +{ + return g->last_error; } -/* Wait for subprocess to exit. */ static void -wait_subprocess (guestfs_h *g) +set_last_error (guestfs_h *g, const char *msg) { - if (g->pid >= 0) waitpid (g->pid, NULL, 0); - g->pid = -1; + free (g->last_error); + g->last_error = strdup (msg); } -static int -error (guestfs_h *g, const char *fs, ...) +static void +default_error_cb (guestfs_h *g, void *data, const char *msg) +{ + fprintf (stderr, _("libguestfs: error: %s\n"), msg); +} + +void +guestfs_error (guestfs_h *g, const char *fs, ...) { va_list args; + char *msg; - fprintf (stderr, "libguestfs: "); va_start (args, fs); - vfprintf (stderr, fs, args); + int err = vasprintf (&msg, fs, args); va_end (args); - fputc ('\n', stderr); - if (g->exit_on_error) { - guestfs_kill_subprocess (g); - exit (1); - } - return -1; + if (err < 0) return; + + if (g->error_cb) g->error_cb (g, g->error_cb_data, msg); + set_last_error (g, msg); + + free (msg); } -static int -perrorf (guestfs_h *g, const char *fs, ...) +void +guestfs_perrorf (guestfs_h *g, const char *fs, ...) { va_list args; - char buf[256]; - int err = errno; + char *msg; + int errnum = errno; - fprintf (stderr, "libguestfs: "); va_start (args, fs); - vfprintf (stderr, fs, args); + int err = vasprintf (&msg, fs, args); va_end (args); - strerror_r (err, buf, sizeof buf); - fprintf (stderr, ": %s\n", buf); - if (g->exit_on_error) { - guestfs_kill_subprocess (g); - exit (1); - } - return -1; + if (err < 0) return; + +#if !defined(_GNU_SOURCE) || defined(__APPLE__) + char buf[256]; + strerror_r (errnum, buf, sizeof buf); +#else + char _buf[256]; + char *buf; + buf = strerror_r (errnum, _buf, sizeof _buf); +#endif + + msg = safe_realloc (g, msg, strlen (msg) + 2 + strlen (buf) + 1); + strcat (msg, ": "); + strcat (msg, buf); + + if (g->error_cb) g->error_cb (g, g->error_cb_data, msg); + set_last_error (g, msg); + + free (msg); } -static void * -safe_malloc (guestfs_h *g, int nbytes) +void * +guestfs_safe_malloc (guestfs_h *g, size_t nbytes) { void *ptr = malloc (nbytes); - if (!ptr) g->abort_fn (); + if (nbytes > 0 && !ptr) g->abort_cb (); return ptr; } -static void * -safe_realloc (guestfs_h *g, void *ptr, int nbytes) +/* Return 1 if an array of N objects, each of size S, cannot exist due + to size arithmetic overflow. S must be positive and N must be + nonnegative. This is a macro, not an inline function, so that it + works correctly even when SIZE_MAX < N. + + By gnulib convention, SIZE_MAX represents overflow in size + calculations, so the conservative dividend to use here is + SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value. + However, malloc (SIZE_MAX) fails on all known hosts where + sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for + exactly-SIZE_MAX allocations on such hosts; this avoids a test and + branch when S is known to be 1. */ +# define xalloc_oversized(n, s) \ + ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n)) + +/* Technically we should add an autoconf test for this, testing for the desired + functionality, like what's done in gnulib, but for now, this is fine. */ +#if defined(__GLIBC__) +#define HAVE_GNU_CALLOC (__GLIBC__ >= 2) +#else +#define HAVE_GNU_CALLOC 0 +#endif + +/* Allocate zeroed memory for N elements of S bytes, with error + checking. S must be nonzero. */ +void * +guestfs_safe_calloc (guestfs_h *g, size_t n, size_t s) +{ + /* From gnulib's calloc function in xmalloc.c. */ + void *p; + /* Test for overflow, since some calloc implementations don't have + proper overflow checks. But omit overflow and size-zero tests if + HAVE_GNU_CALLOC, since GNU calloc catches overflow and never + returns NULL if successful. */ + if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s)) + || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0))) + g->abort_cb (); + return p; +} + +void * +guestfs_safe_realloc (guestfs_h *g, void *ptr, int nbytes) { void *p = realloc (ptr, nbytes); - if (!p) g->abort_fn (); + if (nbytes > 0 && !p) g->abort_cb (); return p; } -static char * -safe_strdup (guestfs_h *g, const char *str) +char * +guestfs_safe_strdup (guestfs_h *g, const char *str) { char *s = strdup (str); - if (!s) g->abort_fn (); + if (!s) g->abort_cb (); return s; } +void * +guestfs_safe_memdup (guestfs_h *g, void *ptr, size_t size) +{ + void *p = malloc (size); + if (!p) g->abort_cb (); + memcpy (p, ptr, size); + return p; +} + +static int +xwrite (int fd, const void *v_buf, size_t len) +{ + const char *buf = v_buf; + int r; + + while (len > 0) { + r = write (fd, buf, len); + if (r == -1) + return -1; + + buf += r; + len -= r; + } + + return 0; +} + void -guestfs_set_out_of_memory_handler (guestfs_h *g, guestfs_abort_fn a) +guestfs_set_out_of_memory_handler (guestfs_h *g, guestfs_abort_cb cb) { - g->abort_fn = a; + g->abort_cb = cb; } -guestfs_abort_fn +guestfs_abort_cb guestfs_get_out_of_memory_handler (guestfs_h *g) { - return g->abort_fn; + return g->abort_cb; } void -guestfs_set_exit_on_error (guestfs_h *g, int e) +guestfs_set_error_handler (guestfs_h *g, guestfs_error_handler_cb cb, void *data) { - g->exit_on_error = e; + g->error_cb = cb; + g->error_cb_data = data; } -int -guestfs_get_exit_on_error (guestfs_h *g) +guestfs_error_handler_cb +guestfs_get_error_handler (guestfs_h *g, void **data_rtn) { - return g->exit_on_error; + if (data_rtn) *data_rtn = g->error_cb_data; + return g->error_cb; } -void -guestfs_set_verbose (guestfs_h *g, int v) +int +guestfs__set_verbose (guestfs_h *g, int v) { - g->verbose = v; + g->verbose = !!v; + return 0; } int -guestfs_get_verbose (guestfs_h *g) +guestfs__get_verbose (guestfs_h *g) { return g->verbose; } -/* Add an escaped string to the current command line. */ -static int -add_cmdline (guestfs_h *g, const char *str) +int +guestfs__set_autosync (guestfs_h *g, int a) { - if (g->pid >= 0) - return error (g, "command line cannot be altered after qemu subprocess launched"); - - g->cmdline_size++; - g->cmdline = safe_realloc (g, g->cmdline, sizeof (char *) * g->cmdline_size); - g->cmdline[g->cmdline_size-1] = safe_strdup (g, str); - + g->autosync = !!a; return 0; } int -guestfs_config (guestfs_h *g, - const char *qemu_param, const char *qemu_value) +guestfs__get_autosync (guestfs_h *g) { - if (qemu_param[0] != '-') - return error (g, "guestfs_config: parameter must begin with '-' character"); - - /* A bit fascist, but the user will probably break the extra - * parameters that we add if they try to set any of these. - */ - if (strcmp (qemu_param, "-kernel") == 0 || - strcmp (qemu_param, "-initrd") == 0 || - strcmp (qemu_param, "-nographic") == 0 || - strcmp (qemu_param, "-serial") == 0 || - strcmp (qemu_param, "-vnc") == 0 || - strcmp (qemu_param, "-full-screen") == 0 || - strcmp (qemu_param, "-std-vga") == 0 || - strcmp (qemu_param, "-vnc") == 0) - return error (g, "guestfs_config: parameter '%s' isn't allowed"); - - if (add_cmdline (g, qemu_param) != 0) return -1; + return g->autosync; +} - if (qemu_value != NULL) { - if (add_cmdline (g, qemu_value) != 0) return -1; - } +int +guestfs__set_path (guestfs_h *g, const char *path) +{ + free (g->path); + g->path = NULL; + g->path = + path == NULL ? + safe_strdup (g, GUESTFS_DEFAULT_PATH) : safe_strdup (g, path); return 0; } -int -guestfs_add_drive (guestfs_h *g, const char *filename) +const char * +guestfs__get_path (guestfs_h *g) { - int len = strlen (filename) + 64; - char buf[len]; + return g->path; +} - if (strchr (filename, ',') != NULL) - return error (g, "filename cannot contain ',' (comma) character"); +int +guestfs__set_qemu (guestfs_h *g, const char *qemu) +{ + free (g->qemu); + g->qemu = NULL; - snprintf (buf, len, "file=%s,media=disk", filename); + g->qemu = qemu == NULL ? safe_strdup (g, QEMU) : safe_strdup (g, qemu); + return 0; +} - return guestfs_config (g, "-drive", buf); +const char * +guestfs__get_qemu (guestfs_h *g) +{ + return g->qemu; } int -guestfs_add_cdrom (guestfs_h *g, const char *filename) +guestfs__set_append (guestfs_h *g, const char *append) { - int len = strlen (filename) + 64; - char buf[len]; + free (g->append); + g->append = NULL; - if (strchr (filename, ',') != NULL) - return error (g, "filename cannot contain ',' (comma) character"); + g->append = append ? safe_strdup (g, append) : NULL; + return 0; +} - snprintf (buf, len, "file=%s,if=ide,index=1,media=cdrom", filename); +const char * +guestfs__get_append (guestfs_h *g) +{ + return g->append; +} - return guestfs_config (g, "-drive", buf); +int +guestfs__set_memsize (guestfs_h *g, int memsize) +{ + g->memsize = memsize; + return 0; } int -guestfs_launch (guestfs_h *g) +guestfs__get_memsize (guestfs_h *g) { - static const char *dir_template = "/tmp/libguestfsXXXXXX"; - int r, i; - /*const char *qemu = QEMU;*/ /* XXX */ - const char *qemu = "/home/rjones/d/redhat/libguestfs/qemu"; - const char *kernel = "/boot/vmlinuz-2.6.27.15-170.2.24.fc10.x86_64"; - const char *initrd = "/tmp/initrd-2.6.27.15-170.2.24.fc10.x86_64.img"; - char unixsock[256]; + return g->memsize; +} - /* XXX Choose which qemu to run. */ - /* XXX Choose initrd, etc. */ +int +guestfs__set_selinux (guestfs_h *g, int selinux) +{ + g->selinux = selinux; + return 0; +} - /* Make the temporary directory containing the logfile and socket. */ - if (!g->tmpdir) { - g->tmpdir = safe_strdup (g, dir_template); - if (mkdtemp (g->tmpdir) == NULL) - return perrorf (g, "%s: cannot create temporary directory", dir_template); +int +guestfs__get_selinux (guestfs_h *g) +{ + return g->selinux; +} - snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir); +int +guestfs__get_pid (guestfs_h *g) +{ + if (g->pid > 0) + return g->pid; + else { + error (g, "get_pid: no qemu subprocess"); + return -1; } +} - r = fork (); - if (r == -1) - return perrorf (g, "fork"); +struct guestfs_version * +guestfs__version (guestfs_h *g) +{ + struct guestfs_version *r; + + r = safe_malloc (g, sizeof *r); + r->major = PACKAGE_VERSION_MAJOR; + r->minor = PACKAGE_VERSION_MINOR; + r->release = PACKAGE_VERSION_RELEASE; + r->extra = safe_strdup (g, PACKAGE_VERSION_EXTRA); + return r; +} - if (r > 0) { /* Parent (library). */ - g->pid = r; +int +guestfs__set_trace (guestfs_h *g, int t) +{ + g->trace = !!t; + return 0; +} - /* If qemu is going to die during startup, give it a tiny amount - * of time to print the error message. - */ - usleep (10000); +int +guestfs__get_trace (guestfs_h *g) +{ + return g->trace; +} - /* Start the clock ... */ - time (&g->start_t); - } - else { /* Child (qemu). */ - char vmchannel[256]; - char logfile[256]; - char append[256]; +int +guestfs__set_direct (guestfs_h *g, int d) +{ + g->direct = !!d; + return 0; +} - /* Set up the full command line. Do this in the subprocess so we - * don't need to worry about cleaning up. - */ - g->cmdline[0] = (char *) qemu; +int +guestfs__get_direct (guestfs_h *g) +{ + return g->direct; +} - g->cmdline = - realloc (g->cmdline, sizeof (char *) * (g->cmdline_size + 16)); - if (g->cmdline == NULL) { - perror ("realloc"); - _exit (1); - } +int +guestfs__set_recovery_proc (guestfs_h *g, int f) +{ + g->recovery_proc = !!f; + return 0; +} - /* Construct the -net channel parameter for qemu. */ - snprintf (vmchannel, sizeof vmchannel, - "channel,%d:unix:%s,server,nowait", VMCHANNEL_PORT, unixsock); +int +guestfs__get_recovery_proc (guestfs_h *g) +{ + return g->recovery_proc; +} - /* Linux kernel command line. */ - snprintf (append, sizeof append, - "console=ttyS0 guestfs=%s:%d", VMCHANNEL_ADDR, VMCHANNEL_PORT); - - /* XXX -m */ - - g->cmdline[g->cmdline_size ] = "-kernel"; - g->cmdline[g->cmdline_size+ 1] = (char *) kernel; - g->cmdline[g->cmdline_size+ 2] = "-initrd"; - g->cmdline[g->cmdline_size+ 3] = (char *) initrd; - g->cmdline[g->cmdline_size+ 4] = "-append"; - g->cmdline[g->cmdline_size+ 5] = append; - g->cmdline[g->cmdline_size+ 6] = "-nographic"; - g->cmdline[g->cmdline_size+ 7] = "-serial"; - g->cmdline[g->cmdline_size+ 8] = "stdio"; - g->cmdline[g->cmdline_size+ 9] = "-net"; - g->cmdline[g->cmdline_size+10] = vmchannel; - g->cmdline[g->cmdline_size+11] = "-net"; - g->cmdline[g->cmdline_size+12] = "user,vlan=0"; - g->cmdline[g->cmdline_size+13] = "-net"; - g->cmdline[g->cmdline_size+14] = "nic,vlan=0"; - g->cmdline[g->cmdline_size+15] = NULL; - - if (g->verbose) { - fprintf (stderr, "Running %s", qemu); - for (i = 0; g->cmdline[i]; ++i) - fprintf (stderr, " %s", g->cmdline[i]); - fprintf (stderr, "\n"); - } - - /* Set up stdin, stdout. Messages should go to the logfile. */ - close (0); - close (1); - open ("/dev/null", O_RDONLY); - snprintf (logfile, sizeof logfile, "%s/qemu.log", g->tmpdir); - open (logfile, O_WRONLY|O_CREAT|O_APPEND, 0644); - /*dup2 (1, 2);*/ +/* Add a string to the current command line. */ +static void +incr_cmdline_size (guestfs_h *g) +{ + if (g->cmdline == NULL) { + /* g->cmdline[0] is reserved for argv[0], set in guestfs_launch. */ + g->cmdline_size = 1; + g->cmdline = safe_malloc (g, sizeof (char *)); + g->cmdline[0] = NULL; + } - /* Set up a new process group, so we can signal this process - * and all subprocesses (eg. if qemu is really a shell script). - */ - setpgid (0, 0); + g->cmdline_size++; + g->cmdline = safe_realloc (g, g->cmdline, sizeof (char *) * g->cmdline_size); +} - execv (qemu, g->cmdline); /* Run qemu. */ - perror (qemu); - _exit (1); +static int +add_cmdline (guestfs_h *g, const char *str) +{ + if (g->state != CONFIG) { + error (g, + _("command line cannot be altered after qemu subprocess launched")); + return -1; } + incr_cmdline_size (g); + g->cmdline[g->cmdline_size-1] = safe_strdup (g, str); return 0; } -/* A peculiarity of qemu's vmchannel implementation is that both sides - * connect to qemu, ie: - * - * libguestfs --- connect --> qemu <-- connect --- daemon - * (host) (guest) - * - * This has several implications: (1) qemu creates the Unix socket, so - * we have to wait for it to do that. (2) we have to arrange for the - * daemon to send a "hello" message which we also wait for. - * - * At any time during this, the qemu subprocess might run slowly, die - * or hang (it's very prone to just hanging if the BIOS fails for any - * reason or if the kernel cannot be found to boot from). - * - * The only realistic way to handle this is, unfortunately, using - * timeouts, also checking if the qemu subprocess is still alive. - * - * We could do better here by monitoring the Linux kernel log messages - * (via the serial console, which is currently just redirected to a - * log file) and seeing if the Linux guest is making progress. (XXX) - */ +int +guestfs__config (guestfs_h *g, + const char *qemu_param, const char *qemu_value) +{ + if (qemu_param[0] != '-') { + error (g, _("guestfs_config: parameter must begin with '-' character")); + return -1; + } + + /* A bit fascist, but the user will probably break the extra + * parameters that we add if they try to set any of these. + */ + if (STREQ (qemu_param, "-kernel") || + STREQ (qemu_param, "-initrd") || + STREQ (qemu_param, "-nographic") || + STREQ (qemu_param, "-serial") || + STREQ (qemu_param, "-full-screen") || + STREQ (qemu_param, "-std-vga") || + STREQ (qemu_param, "-vnc")) { + error (g, _("guestfs_config: parameter '%s' isn't allowed"), qemu_param); + return -1; + } -#define QEMU_SOCKET_TIMEOUT 5 /* How long we wait for qemu to make - * the socket. This should be very quick. - */ -#define DAEMON_TIMEOUT 60 /* How long we wait for guest to boot - * and start the daemon. This could take - * a potentially long time, and is very - * sensitive to the overall load on the host. - */ + if (add_cmdline (g, qemu_param) != 0) return -1; + + if (qemu_value != NULL) { + if (add_cmdline (g, qemu_value) != 0) return -1; + } -static int wait_ready (guestfs_h *g); + return 0; +} int -guestfs_wait_ready (guestfs_h *g) +guestfs__add_drive_with_if (guestfs_h *g, const char *filename, + const char *drive_if) { - int r; + size_t len = strlen (filename) + 64; + char buf[len]; - /* Launch the subprocess, if there isn't one already. */ - if (g->pid == -1) { - if (guestfs_launch (g) != 0) - return -1; + if (strchr (filename, ',') != NULL) { + error (g, _("filename cannot contain ',' (comma) character")); + return -1; } - for (;;) { - r = wait_ready (g); - if (r == -1) { /* Error. */ - guestfs_kill_subprocess (g); + /* cache=off improves reliability in the event of a host crash. + * + * However this option causes qemu to try to open the file with + * O_DIRECT. This fails on some filesystem types (notably tmpfs). + * So we check if we can open the file with or without O_DIRECT, + * and use cache=off (or not) accordingly. + * + * This test also checks for the presence of the file, which + * is a documented semantic of this interface. + */ + int fd = open (filename, O_RDONLY|O_DIRECT); + if (fd >= 0) { + close (fd); + snprintf (buf, len, "file=%s,cache=off,if=%s", filename, drive_if); + } else { + fd = open (filename, O_RDONLY); + if (fd >= 0) { + close (fd); + snprintf (buf, len, "file=%s,if=%s", filename, drive_if); + } else { + perrorf (g, "%s", filename); return -1; } - else if (r > 0) { /* Keep waiting. */ - sleep (1); - continue; - } - else if (r == 0) /* Daemon is ready. */ - break; } - return 0; + return guestfs__config (g, "-drive", buf); } -#define UNIX_PATH_MAX 108 - -/* This function is called repeatedly until the qemu subprocess and - * daemon is ready. It returns: - * -1 : error - * 0 : done, daemon is ready - * >0 : not ready, keep waiting - */ -static int -wait_ready (guestfs_h *g) +int +guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename, + const char *drive_if) { - int r, i, sock; - time_t now; - double elapsed; - struct sockaddr_un addr; - unsigned char m; - - if (g->pid == -1) abort (); /* Internal state error. */ - - /* Check the daemon is still around. */ - r = waitpid (g->pid, NULL, WNOHANG); + if (strchr (filename, ',') != NULL) { + error (g, _("filename cannot contain ',' (comma) character")); + return -1; + } - if (r > 0 || (r == -1 && errno == ECHILD)) { - g->pid = -1; - return error (g, - "qemu subprocess exited unexpectedly during initialization"); + if (access (filename, F_OK) == -1) { + perrorf (g, "%s", filename); + return -1; } - time (&now); - elapsed = difftime (now, g->start_t); + if (qemu_supports (g, NULL) == -1) + return -1; - if (g->sock == -1) { - /* Create the socket. */ - sock = socket (AF_UNIX, SOCK_STREAM, 0); - if (sock == -1) - return perrorf (g, "socket"); + /* Only SCSI and virtio drivers support readonly mode. + * This is only supported as a QEMU feature since 2010/01. + */ + int supports_ro = 0; + if ((STREQ (drive_if, "scsi") || STREQ (drive_if, "virtio")) && + qemu_supports (g, "readonly=on")) + supports_ro = 1; + + size_t len = strlen (filename) + 100; + char buf[len]; + + snprintf (buf, len, "file=%s,snapshot=on,%sif=%s", + filename, + supports_ro ? "readonly=on," : "", + drive_if); + + return guestfs__config (g, "-drive", buf); +} + +int +guestfs__add_drive (guestfs_h *g, const char *filename) +{ + return guestfs__add_drive_with_if (g, filename, DRIVE_IF); +} + +int +guestfs__add_drive_ro (guestfs_h *g, const char *filename) +{ + return guestfs__add_drive_ro_with_if (g, filename, DRIVE_IF); +} + +int +guestfs__add_cdrom (guestfs_h *g, const char *filename) +{ + if (strchr (filename, ',') != NULL) { + error (g, _("filename cannot contain ',' (comma) character")); + return -1; + } + + if (access (filename, F_OK) == -1) { + perrorf (g, "%s", filename); + return -1; + } + + return guestfs__config (g, "-cdrom", filename); +} + +/* Returns true iff file is contained in dir. */ +static int +dir_contains_file (const char *dir, const char *file) +{ + int dirlen = strlen (dir); + int filelen = strlen (file); + int len = dirlen+filelen+2; + char path[len]; + + snprintf (path, len, "%s/%s", dir, file); + return access (path, F_OK) == 0; +} + +/* Returns true iff every listed file is contained in 'dir'. */ +static int +dir_contains_files (const char *dir, ...) +{ + va_list args; + const char *file; + + va_start (args, dir); + while ((file = va_arg (args, const char *)) != NULL) { + if (!dir_contains_file (dir, file)) { + va_end (args); + return 0; + } + } + va_end (args); + return 1; +} + +static void print_timestamped_message (guestfs_h *g, const char *fs, ...); +static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd); +static int is_openable (guestfs_h *g, const char *path, int flags); +static void print_cmdline (guestfs_h *g); + +static const char *kernel_name = "vmlinuz." REPO "." host_cpu; +static const char *initrd_name = "initramfs." REPO "." host_cpu ".img"; + +int +guestfs__launch (guestfs_h *g) +{ + const char *tmpdir; + char dir_template[PATH_MAX]; + int r, pmore; + size_t len; + int wfd[2], rfd[2]; + int tries; + char *path, *pelem, *pend; + char *kernel = NULL, *initrd = NULL; + int null_vmchannel_sock; + char unixsock[256]; + struct sockaddr_un addr; + + /* Configured? */ + if (!g->cmdline) { + error (g, _("you must call guestfs_add_drive before guestfs_launch")); + return -1; + } + + if (g->state != CONFIG) { + error (g, _("the libguestfs handle has already been launched")); + return -1; + } + + /* Start the clock ... */ + gettimeofday (&g->launch_t, NULL); + + /* Make the temporary directory. */ +#ifdef P_tmpdir + tmpdir = P_tmpdir; +#else + tmpdir = "/tmp"; +#endif + + tmpdir = getenv ("TMPDIR") ? : tmpdir; + snprintf (dir_template, sizeof dir_template, "%s/libguestfsXXXXXX", tmpdir); + + if (!g->tmpdir) { + g->tmpdir = safe_strdup (g, dir_template); + if (mkdtemp (g->tmpdir) == NULL) { + perrorf (g, _("%s: cannot create temporary directory"), dir_template); + goto cleanup0; + } + } + + /* First search g->path for the supermin appliance, and try to + * synthesize a kernel and initrd from that. If it fails, we + * try the path search again looking for a backup ordinary + * appliance. + */ + pelem = path = safe_strdup (g, g->path); + do { + pend = strchrnul (pelem, ':'); + pmore = *pend == ':'; + *pend = '\0'; + len = pend - pelem; + + /* Empty element of "." means cwd. */ + if (len == 0 || (len == 1 && *pelem == '.')) { + if (g->verbose) + fprintf (stderr, + "looking for supermin appliance in current directory\n"); + if (dir_contains_files (".", + "supermin.d", "kmod.whitelist", NULL)) { + if (build_supermin_appliance (g, ".", &kernel, &initrd) == -1) + return -1; + break; + } + } + /* Look at /supermin* etc. */ + else { + if (g->verbose) + fprintf (stderr, "looking for supermin appliance in %s\n", pelem); + + if (dir_contains_files (pelem, + "supermin.d", "kmod.whitelist", NULL)) { + if (build_supermin_appliance (g, pelem, &kernel, &initrd) == -1) + return -1; + break; + } + } + + pelem = pend + 1; + } while (pmore); + + free (path); + + if (kernel == NULL || initrd == NULL) { + /* Search g->path for the kernel and initrd. */ + pelem = path = safe_strdup (g, g->path); + do { + pend = strchrnul (pelem, ':'); + pmore = *pend == ':'; + *pend = '\0'; + len = pend - pelem; + + /* Empty element or "." means cwd. */ + if (len == 0 || (len == 1 && *pelem == '.')) { + if (g->verbose) + fprintf (stderr, + "looking for appliance in current directory\n"); + if (dir_contains_files (".", kernel_name, initrd_name, NULL)) { + kernel = safe_strdup (g, kernel_name); + initrd = safe_strdup (g, initrd_name); + break; + } + } + /* Look at /kernel etc. */ + else { + if (g->verbose) + fprintf (stderr, "looking for appliance in %s\n", pelem); + + if (dir_contains_files (pelem, kernel_name, initrd_name, NULL)) { + kernel = safe_malloc (g, len + strlen (kernel_name) + 2); + initrd = safe_malloc (g, len + strlen (initrd_name) + 2); + sprintf (kernel, "%s/%s", pelem, kernel_name); + sprintf (initrd, "%s/%s", pelem, initrd_name); + break; + } + } + + pelem = pend + 1; + } while (pmore); + + free (path); + } + + if (kernel == NULL || initrd == NULL) { + error (g, _("cannot find %s or %s on LIBGUESTFS_PATH (current path = %s)"), + kernel_name, initrd_name, g->path); + goto cleanup0; + } + + if (g->verbose) + print_timestamped_message (g, "begin testing qemu features"); + + /* Get qemu help text and version. */ + if (qemu_supports (g, NULL) == -1) + goto cleanup0; + + /* Choose which vmchannel implementation to use. */ + if (CAN_CHECK_PEER_EUID && qemu_supports (g, "-net user")) { + /* The "null vmchannel" implementation. Requires SLIRP (user mode + * networking in qemu) but no other vmchannel support. The daemon + * will connect back to a random port number on localhost. + */ + struct sockaddr_in addr; + socklen_t addrlen = sizeof addr; + + g->sock = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP); + if (g->sock == -1) { + perrorf (g, "socket"); + goto cleanup0; + } + addr.sin_family = AF_INET; + addr.sin_port = htons (0); + addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK); + if (bind (g->sock, (struct sockaddr *) &addr, addrlen) == -1) { + perrorf (g, "bind"); + goto cleanup0; + } + + if (listen (g->sock, 256) == -1) { + perrorf (g, "listen"); + goto cleanup0; + } + + if (getsockname (g->sock, (struct sockaddr *) &addr, &addrlen) == -1) { + perrorf (g, "getsockname"); + goto cleanup0; + } + + if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) { + perrorf (g, "fcntl"); + goto cleanup0; + } + + null_vmchannel_sock = ntohs (addr.sin_port); + if (g->verbose) + fprintf (stderr, "null_vmchannel_sock = %d\n", null_vmchannel_sock); + } else { + /* Using some vmchannel impl. We need to create a local Unix + * domain socket for qemu to use. + */ + snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir); + unlink (unixsock); + null_vmchannel_sock = 0; + } + + if (!g->direct) { + if (pipe (wfd) == -1 || pipe (rfd) == -1) { + perrorf (g, "pipe"); + goto cleanup0; + } + } + + if (g->verbose) + print_timestamped_message (g, "finished testing qemu features"); + + r = fork (); + if (r == -1) { + perrorf (g, "fork"); + if (!g->direct) { + close (wfd[0]); + close (wfd[1]); + close (rfd[0]); + close (rfd[1]); + } + goto cleanup0; + } + + if (r == 0) { /* Child (qemu). */ + char buf[256]; + const char *vmchannel = NULL; + + /* Set up the full command line. Do this in the subprocess so we + * don't need to worry about cleaning up. + */ + g->cmdline[0] = g->qemu; + + /* qemu sometimes needs this option to enable hardware + * virtualization, but some versions of 'qemu-kvm' will use KVM + * regardless (even where this option appears in the help text). + * It is rumoured that there are versions of qemu where supplying + * this option when hardware virtualization is not available will + * cause qemu to fail, so we we have to check at least that + * /dev/kvm is openable. That's not reliable, since /dev/kvm + * might be openable by qemu but not by us (think: SELinux) in + * which case the user would not get hardware virtualization, + * although at least shouldn't fail. A giant clusterfuck with the + * qemu command line, again. + */ + if (qemu_supports (g, "-enable-kvm") && + is_openable (g, "/dev/kvm", O_RDWR)) + add_cmdline (g, "-enable-kvm"); + + /* Newer versions of qemu (from around 2009/12) changed the + * behaviour of monitors so that an implicit '-monitor stdio' is + * assumed if we are in -nographic mode and there is no other + * -monitor option. Only a single stdio device is allowed, so + * this broke the '-serial stdio' option. There is a new flag + * called -nodefaults which gets rid of all this default crud, so + * let's use that to avoid this and any future surprises. + */ + if (qemu_supports (g, "-nodefaults")) + add_cmdline (g, "-nodefaults"); + + add_cmdline (g, "-nographic"); + add_cmdline (g, "-serial"); + add_cmdline (g, "stdio"); + + snprintf (buf, sizeof buf, "%d", g->memsize); + add_cmdline (g, "-m"); + add_cmdline (g, buf); + + /* Force exit instead of reboot on panic */ + add_cmdline (g, "-no-reboot"); + + /* These options recommended by KVM developers to improve reliability. */ + if (qemu_supports (g, "-no-hpet")) + add_cmdline (g, "-no-hpet"); + + if (qemu_supports (g, "-rtc-td-hack")) + add_cmdline (g, "-rtc-td-hack"); + + /* If qemu has SLIRP (user mode network) enabled then we can get + * away with "no vmchannel", where we just connect back to a random + * host port. + */ + if (null_vmchannel_sock) { + add_cmdline (g, "-net"); + add_cmdline (g, "user,vlan=0,net=" NETWORK); + + snprintf (buf, sizeof buf, + "guestfs_vmchannel=tcp:" ROUTER ":%d", + null_vmchannel_sock); + vmchannel = strdup (buf); + } + + /* New-style -net user,guestfwd=... syntax for guestfwd. See: + * + * http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=c92ef6a22d3c71538fcc48fb61ad353f7ba03b62 + * + * The original suggested format doesn't work, see: + * + * http://lists.gnu.org/archive/html/qemu-devel/2009-07/msg01654.html + * + * However Gerd Hoffman privately suggested to me using -chardev + * instead, which does work. + */ + else if (qemu_supports (g, "-chardev") && qemu_supports (g, "guestfwd")) { + snprintf (buf, sizeof buf, + "socket,id=guestfsvmc,path=%s,server,nowait", unixsock); + + add_cmdline (g, "-chardev"); + add_cmdline (g, buf); + + snprintf (buf, sizeof buf, + "user,vlan=0,net=" NETWORK "," + "guestfwd=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT + "-chardev:guestfsvmc"); + + add_cmdline (g, "-net"); + add_cmdline (g, buf); + + vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT; + } + + /* Not guestfwd. HOPEFULLY this qemu uses the older -net channel + * syntax, or if not then we'll get a quick failure. + */ + else { + snprintf (buf, sizeof buf, + "channel," GUESTFWD_PORT ":unix:%s,server,nowait", unixsock); + + add_cmdline (g, "-net"); + add_cmdline (g, buf); + add_cmdline (g, "-net"); + add_cmdline (g, "user,vlan=0,net=" NETWORK); + + vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT; + } + add_cmdline (g, "-net"); + add_cmdline (g, "nic,model=" NET_IF ",vlan=0"); + +#define LINUX_CMDLINE \ + "panic=1 " /* force kernel to panic if daemon exits */ \ + "console=ttyS0 " /* serial console */ \ + "udevtimeout=300 " /* good for very slow systems (RHBZ#480319) */ \ + "noapic " /* workaround for RHBZ#502058 - ok if not SMP */ \ + "acpi=off " /* we don't need ACPI, turn it off */ \ + "printk.time=1 " /* display timestamp before kernel messages */ \ + "cgroup_disable=memory " /* saves us about 5 MB of RAM */ + + /* Linux kernel command line. */ + snprintf (buf, sizeof buf, + LINUX_CMDLINE + "%s " /* (selinux) */ + "%s " /* (vmchannel) */ + "%s " /* (verbose) */ + "TERM=%s " /* (TERM environment variable) */ + "%s", /* (append) */ + g->selinux ? "selinux=1 enforcing=0" : "selinux=0", + vmchannel ? vmchannel : "", + g->verbose ? "guestfs_verbose=1" : "", + getenv ("TERM") ? : "linux", + g->append ? g->append : ""); + + add_cmdline (g, "-kernel"); + add_cmdline (g, (char *) kernel); + add_cmdline (g, "-initrd"); + add_cmdline (g, (char *) initrd); + add_cmdline (g, "-append"); + add_cmdline (g, buf); + + /* Finish off the command line. */ + incr_cmdline_size (g); + g->cmdline[g->cmdline_size-1] = NULL; + + if (g->verbose) + print_cmdline (g); + + if (!g->direct) { + /* Set up stdin, stdout. */ + close (0); + close (1); + close (wfd[1]); + close (rfd[0]); + + if (dup (wfd[0]) == -1) { + dup_failed: + perror ("dup failed"); + _exit (EXIT_FAILURE); + } + if (dup (rfd[1]) == -1) + goto dup_failed; + + close (wfd[0]); + close (rfd[1]); + } + +#if 0 + /* Set up a new process group, so we can signal this process + * and all subprocesses (eg. if qemu is really a shell script). + */ + setpgid (0, 0); +#endif + + setenv ("LC_ALL", "C", 1); + + execv (g->qemu, g->cmdline); /* Run qemu. */ + perror (g->qemu); + _exit (EXIT_FAILURE); + } + + /* Parent (library). */ + g->pid = r; + + free (kernel); + kernel = NULL; + free (initrd); + initrd = NULL; + + /* Fork the recovery process off which will kill qemu if the parent + * process fails to do so (eg. if the parent segfaults). + */ + g->recoverypid = -1; + if (g->recovery_proc) { + r = fork (); + if (r == 0) { + pid_t qemu_pid = g->pid; + pid_t parent_pid = getppid (); + + /* Writing to argv is hideously complicated and error prone. See: + * http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/ps_status.c?rev=1.33.2.1;content-type=text%2Fplain + */ + + /* Loop around waiting for one or both of the other processes to + * disappear. It's fair to say this is very hairy. The PIDs that + * we are looking at might be reused by another process. We are + * effectively polling. Is the cure worse than the disease? + */ + for (;;) { + if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */ + _exit (EXIT_SUCCESS); + if (kill (parent_pid, 0) == -1) { + /* Parent's gone away, qemu still around, so kill qemu. */ + kill (qemu_pid, 9); + _exit (EXIT_SUCCESS); + } + sleep (2); + } + } + + /* Don't worry, if the fork failed, this will be -1. The recovery + * process isn't essential. + */ + g->recoverypid = r; + } + + if (!g->direct) { + /* Close the other ends of the pipe. */ + close (wfd[0]); + close (rfd[1]); + + if (fcntl (wfd[1], F_SETFL, O_NONBLOCK) == -1 || + fcntl (rfd[0], F_SETFL, O_NONBLOCK) == -1) { + perrorf (g, "fcntl"); + goto cleanup1; + } + + g->fd[0] = wfd[1]; /* stdin of child */ + g->fd[1] = rfd[0]; /* stdout of child */ + } else { + g->fd[0] = open ("/dev/null", O_RDWR); + if (g->fd[0] == -1) { + perrorf (g, "open /dev/null"); + goto cleanup1; + } + g->fd[1] = dup (g->fd[0]); + if (g->fd[1] == -1) { + perrorf (g, "dup"); + close (g->fd[0]); + goto cleanup1; + } + } + + if (null_vmchannel_sock) { + int sock = -1; + uid_t uid; + + /* Null vmchannel implementation: We listen on g->sock for a + * connection. The connection could come from any local process + * so we must check it comes from the appliance (or at least + * from our UID) for security reasons. + */ + while (sock == -1) { + sock = accept_from_daemon (g); + if (sock == -1) + goto cleanup1; + + if (check_peer_euid (g, sock, &uid) == -1) + goto cleanup1; + if (uid != geteuid ()) { + fprintf (stderr, + "libguestfs: warning: unexpected connection from UID %d to port %d\n", + uid, null_vmchannel_sock); + close (sock); + sock = -1; + continue; + } + } + + if (fcntl (sock, F_SETFL, O_NONBLOCK) == -1) { + perrorf (g, "fcntl"); + goto cleanup1; + } + + close (g->sock); + g->sock = sock; + } else { + /* Other vmchannel. Open the Unix socket. + * + * The vmchannel implementation that got merged with qemu sucks in + * a number of ways. Both ends do connect(2), which means that no + * one knows what, if anything, is connected to the other end, or + * if it becomes disconnected. Even worse, we have to wait some + * indeterminate time for qemu to create the socket and connect to + * it (which happens very early in qemu's start-up), so any code + * that uses vmchannel is inherently racy. Hence this silly loop. + */ + g->sock = socket (AF_UNIX, SOCK_STREAM, 0); + if (g->sock == -1) { + perrorf (g, "socket"); + goto cleanup1; + } + + if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) { + perrorf (g, "fcntl"); + goto cleanup1; + } + + addr.sun_family = AF_UNIX; + strncpy (addr.sun_path, unixsock, UNIX_PATH_MAX); + addr.sun_path[UNIX_PATH_MAX-1] = '\0'; + + tries = 100; + /* Always sleep at least once to give qemu a small chance to start up. */ + usleep (10000); + while (tries > 0) { + r = connect (g->sock, (struct sockaddr *) &addr, sizeof addr); + if ((r == -1 && errno == EINPROGRESS) || r == 0) + goto connected; + + if (errno != ENOENT) + perrorf (g, "connect"); + tries--; + usleep (100000); + } + + error (g, _("failed to connect to vmchannel socket")); + goto cleanup1; + + connected: ; + } + + g->state = LAUNCHING; + + /* Wait for qemu to start and to connect back to us via vmchannel and + * send the GUESTFS_LAUNCH_FLAG message. + */ + uint32_t size; + void *buf = NULL; + r = recv_from_daemon (g, &size, &buf); + free (buf); + + if (r == -1) return -1; + + if (size != GUESTFS_LAUNCH_FLAG) { + error (g, _("guestfs_launch failed, see earlier error messages")); + goto cleanup1; + } + + if (g->verbose) + print_timestamped_message (g, "appliance is up"); + + /* This is possible in some really strange situations, such as + * guestfsd starts up OK but then qemu immediately exits. Check for + * it because the caller is probably expecting to be able to send + * commands after this function returns. + */ + if (g->state != READY) { + error (g, _("qemu launched and contacted daemon, but state != READY")); + goto cleanup1; + } + + return 0; + + cleanup1: + if (!g->direct) { + close (wfd[1]); + close (rfd[0]); + } + if (g->pid > 0) kill (g->pid, 9); + if (g->recoverypid > 0) kill (g->recoverypid, 9); + waitpid (g->pid, NULL, 0); + if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); + g->fd[0] = -1; + g->fd[1] = -1; + g->pid = 0; + g->recoverypid = 0; + memset (&g->launch_t, 0, sizeof g->launch_t); + + cleanup0: + if (g->sock >= 0) { + close (g->sock); + g->sock = -1; + } + g->state = CONFIG; + free (kernel); + free (initrd); + return -1; +} + +/* This function is used to print the qemu command line before it gets + * executed, when in verbose mode. + */ +static void +print_cmdline (guestfs_h *g) +{ + int i = 0; + int needs_quote; + + while (g->cmdline[i]) { + if (g->cmdline[i][0] == '-') /* -option starts a new line */ + fprintf (stderr, " \\\n "); + + if (i > 0) fputc (' ', stderr); + + /* Does it need shell quoting? This only deals with simple cases. */ + needs_quote = strcspn (g->cmdline[i], " ") != strlen (g->cmdline[i]); + + if (needs_quote) fputc ('\'', stderr); + fprintf (stderr, "%s", g->cmdline[i]); + if (needs_quote) fputc ('\'', stderr); + i++; + } + + fputc ('\n', stderr); +} + +/* This function does the hard work of building the supermin appliance + * on the fly. 'path' is the directory containing the control files. + * 'kernel' and 'initrd' are where we will return the names of the + * kernel and initrd (only initrd is built). The work is done by + * an external script. We just tell it where to put the result. + */ +static int +build_supermin_appliance (guestfs_h *g, const char *path, + char **kernel, char **initrd) +{ + char cmd[4096]; + int r, len; + + if (g->verbose) + print_timestamped_message (g, "begin building supermin appliance"); + + len = strlen (g->tmpdir); + *kernel = safe_malloc (g, len + 8); + snprintf (*kernel, len+8, "%s/kernel", g->tmpdir); + *initrd = safe_malloc (g, len + 8); + snprintf (*initrd, len+8, "%s/initrd", g->tmpdir); + + snprintf (cmd, sizeof cmd, + "febootstrap-supermin-helper%s " + "-k '%s/kmod.whitelist' " + "'%s/supermin.d' " + host_cpu " " + "%s %s", + g->verbose ? " --verbose" : "", + path, + path, + *kernel, *initrd); + if (g->verbose) + print_timestamped_message (g, "%s", cmd); + + r = system (cmd); + if (r == -1 || WEXITSTATUS(r) != 0) { + error (g, _("external command failed: %s"), cmd); + free (*kernel); + free (*initrd); + *kernel = *initrd = NULL; + return -1; + } + + if (g->verbose) + print_timestamped_message (g, "finished building supermin appliance"); + + return 0; +} + +/* Compute Y - X and return the result in milliseconds. + * Approximately the same as this code: + * http://www.mpp.mpg.de/~huber/util/timevaldiff.c + */ +static int64_t +timeval_diff (const struct timeval *x, const struct timeval *y) +{ + int64_t msec; + + msec = (y->tv_sec - x->tv_sec) * 1000; + msec += (y->tv_usec - x->tv_usec) / 1000; + return msec; +} + +static void +print_timestamped_message (guestfs_h *g, const char *fs, ...) +{ + va_list args; + char *msg; + int err; + struct timeval tv; + + va_start (args, fs); + err = vasprintf (&msg, fs, args); + va_end (args); + + if (err < 0) return; + + gettimeofday (&tv, NULL); + + fprintf (stderr, "[%05" PRIi64 "ms] %s\n", + timeval_diff (&g->launch_t, &tv), msg); + + free (msg); +} + +static int read_all (guestfs_h *g, FILE *fp, char **ret); + +/* Test qemu binary (or wrapper) runs, and do 'qemu -help' and + * 'qemu -version' so we know what options this qemu supports and + * the version. + */ +static int +test_qemu (guestfs_h *g) +{ + char cmd[1024]; + FILE *fp; + + snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -nographic -help", g->qemu); + + fp = popen (cmd, "r"); + /* qemu -help should always work (qemu -version OTOH wasn't + * supported by qemu 0.9). If this command doesn't work then it + * probably indicates that the qemu binary is missing. + */ + if (!fp) { + /* XXX This error is never printed, even if the qemu binary + * doesn't exist. Why? + */ + error: + perrorf (g, _("%s: command failed: If qemu is located on a non-standard path, try setting the LIBGUESTFS_QEMU environment variable."), cmd); + return -1; + } + + if (read_all (g, fp, &g->qemu_help) == -1) + goto error; + + if (pclose (fp) == -1) + goto error; + + snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -nographic -version 2>/dev/null", + g->qemu); + + fp = popen (cmd, "r"); + if (fp) { + /* Intentionally ignore errors. */ + read_all (g, fp, &g->qemu_version); + pclose (fp); + } + + return 0; +} + +static int +read_all (guestfs_h *g, FILE *fp, char **ret) +{ + int r, n = 0; + char *p; + + again: + if (feof (fp)) { + *ret = safe_realloc (g, *ret, n + 1); + (*ret)[n] = '\0'; + return n; + } + + *ret = safe_realloc (g, *ret, n + BUFSIZ); + p = &(*ret)[n]; + r = fread (p, 1, BUFSIZ, fp); + if (ferror (fp)) { + perrorf (g, "read"); + return -1; + } + n += r; + goto again; +} + +/* Test if option is supported by qemu command line (just by grepping + * the help text). + * + * The first time this is used, it has to run the external qemu + * binary. If that fails, it returns -1. + * + * To just do the first-time run of the qemu binary, call this with + * option == NULL, in which case it will return -1 if there was an + * error doing that. + */ +static int +qemu_supports (guestfs_h *g, const char *option) +{ + if (!g->qemu_help) { + if (test_qemu (g) == -1) + return -1; + } + + if (option == NULL) + return 1; + + return strstr (g->qemu_help, option) != NULL; +} + +/* Check if a file can be opened. */ +static int +is_openable (guestfs_h *g, const char *path, int flags) +{ + int fd = open (path, flags); + if (fd == -1) { + if (g->verbose) + perror (path); + return 0; + } + close (fd); + return 1; +} + +/* Check the peer effective UID for a TCP socket. Ideally we'd like + * SO_PEERCRED for a loopback TCP socket. This isn't possible on + * Linux (but it is on Solaris!) so we read /proc/net/tcp instead. + */ +static int +check_peer_euid (guestfs_h *g, int sock, uid_t *rtn) +{ +#if CAN_CHECK_PEER_EUID + struct sockaddr_in peer; + socklen_t addrlen = sizeof peer; + + if (getpeername (sock, (struct sockaddr *) &peer, &addrlen) == -1) { + perrorf (g, "getpeername"); + return -1; + } + + if (peer.sin_family != AF_INET || + ntohl (peer.sin_addr.s_addr) != INADDR_LOOPBACK) { + error (g, "check_peer_euid: unexpected connection from non-IPv4, non-loopback peer (family = %d, addr = %s)", + peer.sin_family, inet_ntoa (peer.sin_addr)); + return -1; + } + + struct sockaddr_in our; + addrlen = sizeof our; + if (getsockname (sock, (struct sockaddr *) &our, &addrlen) == -1) { + perrorf (g, "getsockname"); + return -1; + } + + FILE *fp = fopen ("/proc/net/tcp", "r"); + if (fp == NULL) { + perrorf (g, "/proc/net/tcp"); + return -1; + } + + char line[256]; + if (fgets (line, sizeof line, fp) == NULL) { /* Drop first line. */ + error (g, "unexpected end of file in /proc/net/tcp"); + fclose (fp); + return -1; + } + + while (fgets (line, sizeof line, fp) != NULL) { + unsigned line_our_addr, line_our_port, line_peer_addr, line_peer_port; + int dummy0, dummy1, dummy2, dummy3, dummy4, dummy5, dummy6; + int line_uid; + + if (sscanf (line, "%d:%08X:%04X %08X:%04X %02X %08X:%08X %02X:%08X %08X %d", + &dummy0, + &line_our_addr, &line_our_port, + &line_peer_addr, &line_peer_port, + &dummy1, &dummy2, &dummy3, &dummy4, &dummy5, &dummy6, + &line_uid) == 12) { + /* Note about /proc/net/tcp: local_address and rem_address are + * always in network byte order. However the port part is + * always in host byte order. + * + * The sockname and peername that we got above are in network + * byte order. So we have to byte swap the port but not the + * address part. + */ + if (line_our_addr == our.sin_addr.s_addr && + line_our_port == ntohs (our.sin_port) && + line_peer_addr == peer.sin_addr.s_addr && + line_peer_port == ntohs (peer.sin_port)) { + *rtn = line_uid; + fclose (fp); + return 0; + } + } + } + + error (g, "check_peer_euid: no matching TCP connection found in /proc/net/tcp"); + fclose (fp); + return -1; +#else /* !CAN_CHECK_PEER_EUID */ + /* This function exists but should never be called in this + * configuration. + */ + abort (); +#endif /* !CAN_CHECK_PEER_EUID */ +} + +/* You had to call this function after launch in versions <= 1.0.70, + * but it is now a no-op. + */ +int +guestfs__wait_ready (guestfs_h *g) +{ + if (g->state != READY) { + error (g, _("qemu has not been launched yet")); + return -1; + } + + return 0; +} + +int +guestfs__kill_subprocess (guestfs_h *g) +{ + if (g->state == CONFIG) { + error (g, _("no subprocess to kill")); + return -1; + } + + if (g->verbose) + fprintf (stderr, "sending SIGTERM to process %d\n", g->pid); + + if (g->pid > 0) kill (g->pid, SIGTERM); + if (g->recoverypid > 0) kill (g->recoverypid, 9); + + return 0; +} + +/* Access current state. */ +int +guestfs__is_config (guestfs_h *g) +{ + return g->state == CONFIG; +} + +int +guestfs__is_launching (guestfs_h *g) +{ + return g->state == LAUNCHING; +} + +int +guestfs__is_ready (guestfs_h *g) +{ + return g->state == READY; +} + +int +guestfs__is_busy (guestfs_h *g) +{ + return g->state == BUSY; +} + +int +guestfs__get_state (guestfs_h *g) +{ + return g->state; +} + +void +guestfs_set_log_message_callback (guestfs_h *g, + guestfs_log_message_cb cb, void *opaque) +{ + g->log_message_cb = cb; + g->log_message_cb_data = opaque; +} + +void +guestfs_set_subprocess_quit_callback (guestfs_h *g, + guestfs_subprocess_quit_cb cb, void *opaque) +{ + g->subprocess_quit_cb = cb; + g->subprocess_quit_cb_data = opaque; +} + +void +guestfs_set_launch_done_callback (guestfs_h *g, + guestfs_launch_done_cb cb, void *opaque) +{ + g->launch_done_cb = cb; + g->launch_done_cb_data = opaque; +} + +/*----------------------------------------------------------------------*/ + +/* This is the code used to send and receive RPC messages and (for + * certain types of message) to perform file transfers. This code is + * driven from the generated actions (src/guestfs-actions.c). There + * are five different cases to consider: + * + * (1) A non-daemon function. There is no RPC involved at all, it's + * all handled inside the library. + * + * (2) A simple RPC (eg. "mount"). We write the request, then read + * the reply. The sequence of calls is: + * + * guestfs___set_busy + * guestfs___send + * guestfs___recv + * guestfs___end_busy + * + * (3) An RPC with FileOut parameters (eg. "upload"). We write the + * request, then write the file(s), then read the reply. The sequence + * of calls is: + * + * guestfs___set_busy + * guestfs___send + * guestfs___send_file (possibly multiple times) + * guestfs___recv + * guestfs___end_busy + * + * (4) An RPC with FileIn parameters (eg. "download"). We write the + * request, then read the reply, then read the file(s). The sequence + * of calls is: + * + * guestfs___set_busy + * guestfs___send + * guestfs___recv + * guestfs___recv_file (possibly multiple times) + * guestfs___end_busy + * + * (5) Both FileOut and FileIn parameters. There are no calls like + * this in the current API, but they would be implemented as a + * combination of cases (3) and (4). + * + * During all writes and reads, we also select(2) on qemu stdout + * looking for messages (guestfsd stderr and guest kernel dmesg), and + * anything received is passed up through the log_message_cb. This is + * also the reason why all the sockets are non-blocking. We also have + * to check for EOF (qemu died). All of this is handled by the + * functions send_to_daemon and recv_from_daemon. + */ + +int +guestfs___set_busy (guestfs_h *g) +{ + if (g->state != READY) { + error (g, _("guestfs_set_busy: called when in state %d != READY"), + g->state); + return -1; + } + g->state = BUSY; + return 0; +} + +int +guestfs___end_busy (guestfs_h *g) +{ + switch (g->state) + { + case BUSY: + g->state = READY; + break; + case CONFIG: + case READY: + break; - addr.sun_family = AF_UNIX; - snprintf (addr.sun_path, UNIX_PATH_MAX, "%s/sock", g->tmpdir); + case LAUNCHING: + case NO_HANDLE: + default: + error (g, _("guestfs_end_busy: called when in state %d"), g->state); + return -1; + } + return 0; +} - if (connect (sock, (struct sockaddr *) &addr, sizeof addr) == -1) { - if (elapsed <= QEMU_SOCKET_TIMEOUT) { - close (sock); - return 1; /* Keep waiting for the socket ... */ - } - perrorf (g, "qemu process hanging before making vmchannel socket"); - close (sock); +/* This is called if we detect EOF, ie. qemu died. */ +static void +child_cleanup (guestfs_h *g) +{ + if (g->verbose) + fprintf (stderr, "child_cleanup: %p: child process died\n", g); + + /*if (g->pid > 0) kill (g->pid, SIGTERM);*/ + if (g->recoverypid > 0) kill (g->recoverypid, 9); + waitpid (g->pid, NULL, 0); + if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); + close (g->fd[0]); + close (g->fd[1]); + close (g->sock); + g->fd[0] = -1; + g->fd[1] = -1; + g->sock = -1; + g->pid = 0; + g->recoverypid = 0; + memset (&g->launch_t, 0, sizeof g->launch_t); + g->state = CONFIG; + if (g->subprocess_quit_cb) + g->subprocess_quit_cb (g, g->subprocess_quit_cb_data); +} + +static int +read_log_message_or_eof (guestfs_h *g, int fd, int error_if_eof) +{ + char buf[BUFSIZ]; + int n; + +#if 0 + if (g->verbose) + fprintf (stderr, + "read_log_message_or_eof: %p g->state = %d, fd = %d\n", + g, g->state, fd); +#endif + + /* QEMU's console emulates a 16550A serial port. The real 16550A + * device has a small FIFO buffer (16 bytes) which means here we see + * lots of small reads of 1-16 bytes in length, usually single + * bytes. + */ + n = read (fd, buf, sizeof buf); + if (n == 0) { + /* Hopefully this indicates the qemu child process has died. */ + child_cleanup (g); + + if (error_if_eof) { + /* We weren't expecting eof here (called from launch) so place + * something in the error buffer. RHBZ#588851. + */ + error (g, "child process died unexpectedly"); + } + return -1; + } + + if (n == -1) { + if (errno == EINTR || errno == EAGAIN) + return 0; + + perrorf (g, "read"); + return -1; + } + + /* In verbose mode, copy all log messages to stderr. */ + if (g->verbose) + ignore_value (write (STDERR_FILENO, buf, n)); + + /* It's an actual log message, send it upwards if anyone is listening. */ + if (g->log_message_cb) + g->log_message_cb (g, g->log_message_cb_data, buf, n); + + return 0; +} + +static int +check_for_daemon_cancellation_or_eof (guestfs_h *g, int fd) +{ + char buf[4]; + int n; + uint32_t flag; + XDR xdr; + + if (g->verbose) + fprintf (stderr, + "check_for_daemon_cancellation_or_eof: %p g->state = %d, fd = %d\n", + g, g->state, fd); + + n = read (fd, buf, 4); + if (n == 0) { + /* Hopefully this indicates the qemu child process has died. */ + child_cleanup (g); + return -1; + } + + if (n == -1) { + if (errno == EINTR || errno == EAGAIN) + return 0; + + perrorf (g, "read"); + return -1; + } + + xdrmem_create (&xdr, buf, 4, XDR_DECODE); + xdr_uint32_t (&xdr, &flag); + xdr_destroy (&xdr); + + if (flag != GUESTFS_CANCEL_FLAG) { + error (g, _("check_for_daemon_cancellation_or_eof: read 0x%x from daemon, expected 0x%x\n"), + flag, GUESTFS_CANCEL_FLAG); + return -1; + } + + return -2; +} + +/* This writes the whole N bytes of BUF to the daemon socket. + * + * If the whole write is successful, it returns 0. + * If there was an error, it returns -1. + * If the daemon sent a cancellation message, it returns -2. + * + * It also checks qemu stdout for log messages and passes those up + * through log_message_cb. + * + * It also checks for EOF (qemu died) and passes that up through the + * child_cleanup function above. + */ +static int +send_to_daemon (guestfs_h *g, const void *v_buf, size_t n) +{ + const char *buf = v_buf; + fd_set rset, rset2; + fd_set wset, wset2; + + if (g->verbose) + fprintf (stderr, + "send_to_daemon: %p g->state = %d, n = %zu\n", g, g->state, n); + + FD_ZERO (&rset); + FD_ZERO (&wset); + + FD_SET (g->fd[1], &rset); /* Read qemu stdout for log messages & EOF. */ + FD_SET (g->sock, &rset); /* Read socket for cancellation & EOF. */ + FD_SET (g->sock, &wset); /* Write to socket to send the data. */ + + int max_fd = MAX (g->sock, g->fd[1]); + + while (n > 0) { + rset2 = rset; + wset2 = wset; + int r = select (max_fd+1, &rset2, &wset2, NULL, NULL); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "select"); return -1; } - if (fcntl (sock, F_SETFL, O_NONBLOCK) == -1) { - perrorf (g, "set socket non-blocking"); - close (sock); + if (FD_ISSET (g->fd[1], &rset2)) { + if (read_log_message_or_eof (g, g->fd[1], 0) == -1) + return -1; + } + if (FD_ISSET (g->sock, &rset2)) { + r = check_for_daemon_cancellation_or_eof (g, g->sock); + if (r < 0) + return r; + } + if (FD_ISSET (g->sock, &wset2)) { + r = write (g->sock, buf, n); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "write"); + if (errno == EPIPE) /* Disconnected from guest (RHBZ#508713). */ + child_cleanup (g); + return -1; + } + buf += r; + n -= r; + } + } + + return 0; +} + +/* This reads a single message, file chunk, launch flag or + * cancellation flag from the daemon. If something was read, it + * returns 0, otherwise -1. + * + * Both size_rtn and buf_rtn must be passed by the caller as non-NULL. + * + * *size_rtn returns the size of the returned message or it may be + * GUESTFS_LAUNCH_FLAG or GUESTFS_CANCEL_FLAG. + * + * *buf_rtn is returned containing the message (if any) or will be set + * to NULL. *buf_rtn must be freed by the caller. + * + * It also checks qemu stdout for log messages and passes those up + * through log_message_cb. + * + * It also checks for EOF (qemu died) and passes that up through the + * child_cleanup function above. + */ +static int +recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn) +{ + fd_set rset, rset2; + + if (g->verbose) + fprintf (stderr, + "recv_from_daemon: %p g->state = %d, size_rtn = %p, buf_rtn = %p\n", + g, g->state, size_rtn, buf_rtn); + + FD_ZERO (&rset); + + FD_SET (g->fd[1], &rset); /* Read qemu stdout for log messages & EOF. */ + FD_SET (g->sock, &rset); /* Read socket for data & EOF. */ + + int max_fd = MAX (g->sock, g->fd[1]); + + *size_rtn = 0; + *buf_rtn = NULL; + + char lenbuf[4]; + /* nr is the size of the message, but we prime it as -4 because we + * have to read the message length word first. + */ + ssize_t nr = -4; + + while (nr < (ssize_t) *size_rtn) { + rset2 = rset; + int r = select (max_fd+1, &rset2, NULL, NULL, NULL); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "select"); + free (*buf_rtn); + *buf_rtn = NULL; return -1; } - g->sock = sock; + if (FD_ISSET (g->fd[1], &rset2)) { + if (read_log_message_or_eof (g, g->fd[1], 0) == -1) { + free (*buf_rtn); + *buf_rtn = NULL; + return -1; + } + } + if (FD_ISSET (g->sock, &rset2)) { + if (nr < 0) { /* Have we read the message length word yet? */ + r = read (g->sock, lenbuf+nr+4, -nr); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + int err = errno; + perrorf (g, "read"); + /* Under some circumstances we see "Connection reset by peer" + * here when the child dies suddenly. Catch this and call + * the cleanup function, same as for EOF. + */ + if (err == ECONNRESET) + child_cleanup (g); + return -1; + } + if (r == 0) { + error (g, _("unexpected end of file when reading from daemon")); + child_cleanup (g); + return -1; + } + nr += r; + + if (nr < 0) /* Still not got the whole length word. */ + continue; + + XDR xdr; + xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE); + xdr_uint32_t (&xdr, size_rtn); + xdr_destroy (&xdr); + + if (*size_rtn == GUESTFS_LAUNCH_FLAG) { + if (g->state != LAUNCHING) + error (g, _("received magic signature from guestfsd, but in state %d"), + g->state); + else { + g->state = READY; + if (g->launch_done_cb) + g->launch_done_cb (g, g->launch_done_cb_data); + } + return 0; + } + else if (*size_rtn == GUESTFS_CANCEL_FLAG) + return 0; + /* If this happens, it's pretty bad and we've probably lost + * synchronization. + */ + else if (*size_rtn > GUESTFS_MESSAGE_MAX) { + error (g, _("message length (%u) > maximum possible size (%d)"), + (unsigned) *size_rtn, GUESTFS_MESSAGE_MAX); + return -1; + } + + /* Allocate the complete buffer, size now known. */ + *buf_rtn = safe_malloc (g, *size_rtn); + /*FALLTHROUGH*/ + } + + size_t sizetoread = *size_rtn - nr; + if (sizetoread > BUFSIZ) sizetoread = BUFSIZ; + + r = read (g->sock, (char *) (*buf_rtn) + nr, sizetoread); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "read"); + free (*buf_rtn); + *buf_rtn = NULL; + return -1; + } + if (r == 0) { + error (g, _("unexpected end of file when reading from daemon")); + child_cleanup (g); + free (*buf_rtn); + *buf_rtn = NULL; + return -1; + } + nr += r; + } + } + + /* Got the full message, caller can start processing it. */ +#ifdef ENABLE_PACKET_DUMP + if (g->verbose) { + ssize_t i, j; + + for (i = 0; i < nr; i += 16) { + printf ("%04zx: ", i); + for (j = i; j < MIN (i+16, nr); ++j) + printf ("%02x ", (*(unsigned char **)buf_rtn)[j]); + for (; j < i+16; ++j) + printf (" "); + printf ("|"); + for (j = i; j < MIN (i+16, nr); ++j) + if (c_isprint ((*(char **)buf_rtn)[j])) + printf ("%c", (*(char **)buf_rtn)[j]); + else + printf ("."); + for (; j < i+16; ++j) + printf (" "); + printf ("|\n"); + } } +#endif + + return 0; +} + +/* This is very much like recv_from_daemon above, but g->sock is + * a listening socket and we are accepting a new connection on + * that socket instead of reading anything. Returns the newly + * accepted socket. + */ +static int +accept_from_daemon (guestfs_h *g) +{ + fd_set rset, rset2; - if (!g->daemon_up) { - /* Wait for the daemon to say hello. */ - errno = 0; - r = read (g->sock, &m, 1); - if (r == 1) { - if (m == 0xF5) { - g->daemon_up = 1; - return 0; - } else { - error (g, "unexpected message from qemu vmchannel or daemon"); - return -1; + if (g->verbose) + fprintf (stderr, + "accept_from_daemon: %p g->state = %d\n", g, g->state); + + FD_ZERO (&rset); + + FD_SET (g->fd[1], &rset); /* Read qemu stdout for log messages & EOF. */ + FD_SET (g->sock, &rset); /* Read socket for accept. */ + + int max_fd = MAX (g->sock, g->fd[1]); + int sock = -1; + + while (sock == -1) { + /* If the qemu process has died, clean up the zombie (RHBZ#579155). + * By partially polling in the select below we ensure that this + * function will be called eventually. + */ + waitpid (g->pid, NULL, WNOHANG); + + rset2 = rset; + + struct timeval tv = { .tv_sec = 1, .tv_usec = 0 }; + int r = select (max_fd+1, &rset2, NULL, NULL, &tv); + if (r == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "select"); + return -1; + } + + if (FD_ISSET (g->fd[1], &rset2)) { + if (read_log_message_or_eof (g, g->fd[1], 1) == -1) + return -1; + } + if (FD_ISSET (g->sock, &rset2)) { + sock = accept (g->sock, NULL, NULL); + if (sock == -1) { + if (errno == EINTR || errno == EAGAIN) + continue; + perrorf (g, "accept"); + return -1; } } - if (errno == EAGAIN) { - if (elapsed <= DAEMON_TIMEOUT) - return 1; /* Keep waiting for the daemon ... */ - error (g, "timeout waiting for guest to become ready"); + } + + return sock; +} + +int +guestfs___send (guestfs_h *g, int proc_nr, xdrproc_t xdrp, char *args) +{ + struct guestfs_message_header hdr; + XDR xdr; + u_int32_t len; + int serial = g->msg_next_serial++; + int r; + char *msg_out; + size_t msg_out_size; + + if (g->state != BUSY) { + error (g, _("guestfs___send: state %d != BUSY"), g->state); + return -1; + } + + /* We have to allocate this message buffer on the heap because + * it is quite large (although will be mostly unused). We + * can't allocate it on the stack because in some environments + * we have quite limited stack space available, notably when + * running in the JVM. + */ + msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4); + xdrmem_create (&xdr, msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE); + + /* Serialize the header. */ + hdr.prog = GUESTFS_PROGRAM; + hdr.vers = GUESTFS_PROTOCOL_VERSION; + hdr.proc = proc_nr; + hdr.direction = GUESTFS_DIRECTION_CALL; + hdr.serial = serial; + hdr.status = GUESTFS_STATUS_OK; + + if (!xdr_guestfs_message_header (&xdr, &hdr)) { + error (g, _("xdr_guestfs_message_header failed")); + goto cleanup1; + } + + /* Serialize the args. If any, because some message types + * have no parameters. + */ + if (xdrp) { + if (!(*xdrp) (&xdr, args)) { + error (g, _("dispatch failed to marshal args")); + goto cleanup1; + } + } + + /* Get the actual length of the message, resize the buffer to match + * the actual length, and write the length word at the beginning. + */ + len = xdr_getpos (&xdr); + xdr_destroy (&xdr); + + msg_out = safe_realloc (g, msg_out, len + 4); + msg_out_size = len + 4; + + xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE); + xdr_uint32_t (&xdr, &len); + + again: + r = send_to_daemon (g, msg_out, msg_out_size); + if (r == -2) /* Ignore stray daemon cancellations. */ + goto again; + if (r == -1) + goto cleanup1; + free (msg_out); + + return serial; + + cleanup1: + free (msg_out); + return -1; +} + +static int cancel = 0; /* XXX Implement file cancellation. */ +static int send_file_chunk (guestfs_h *g, int cancel, const char *buf, size_t len); +static int send_file_data (guestfs_h *g, const char *buf, size_t len); +static int send_file_cancellation (guestfs_h *g); +static int send_file_complete (guestfs_h *g); + +/* Send a file. + * Returns: + * 0 OK + * -1 error + * -2 daemon cancelled (we must read the error message) + */ +int +guestfs___send_file (guestfs_h *g, const char *filename) +{ + char buf[GUESTFS_MAX_CHUNK_SIZE]; + int fd, r, err; + + fd = open (filename, O_RDONLY); + if (fd == -1) { + perrorf (g, "open: %s", filename); + send_file_cancellation (g); + /* Daemon sees cancellation and won't reply, so caller can + * just return here. + */ + return -1; + } + + /* Send file in chunked encoding. */ + while (!cancel) { + r = read (fd, buf, sizeof buf); + if (r == -1 && (errno == EINTR || errno == EAGAIN)) + continue; + if (r <= 0) break; + err = send_file_data (g, buf, r); + if (err < 0) { + if (err == -2) /* daemon sent cancellation */ + send_file_cancellation (g); + return err; + } + } + + if (cancel) { /* cancel from either end */ + send_file_cancellation (g); + return -1; + } + + if (r == -1) { + perrorf (g, "read: %s", filename); + send_file_cancellation (g); + return -1; + } + + /* End of file, but before we send that, we need to close + * the file and check for errors. + */ + if (close (fd) == -1) { + perrorf (g, "close: %s", filename); + send_file_cancellation (g); + return -1; + } + + return send_file_complete (g); +} + +/* Send a chunk of file data. */ +static int +send_file_data (guestfs_h *g, const char *buf, size_t len) +{ + return send_file_chunk (g, 0, buf, len); +} + +/* Send a cancellation message. */ +static int +send_file_cancellation (guestfs_h *g) +{ + return send_file_chunk (g, 1, NULL, 0); +} + +/* Send a file complete chunk. */ +static int +send_file_complete (guestfs_h *g) +{ + char buf[1]; + return send_file_chunk (g, 0, buf, 0); +} + +static int +send_file_chunk (guestfs_h *g, int cancel, const char *buf, size_t buflen) +{ + u_int32_t len; + int r; + guestfs_chunk chunk; + XDR xdr; + char *msg_out; + size_t msg_out_size; + + if (g->state != BUSY) { + error (g, _("send_file_chunk: state %d != READY"), g->state); + return -1; + } + + /* Allocate the chunk buffer. Don't use the stack to avoid + * excessive stack usage and unnecessary copies. + */ + msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48); + xdrmem_create (&xdr, msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE); + + /* Serialize the chunk. */ + chunk.cancel = cancel; + chunk.data.data_len = buflen; + chunk.data.data_val = (char *) buf; + + if (!xdr_guestfs_chunk (&xdr, &chunk)) { + error (g, _("xdr_guestfs_chunk failed (buf = %p, buflen = %zu)"), + buf, buflen); + xdr_destroy (&xdr); + goto cleanup1; + } + + len = xdr_getpos (&xdr); + xdr_destroy (&xdr); + + /* Reduce the size of the outgoing message buffer to the real length. */ + msg_out = safe_realloc (g, msg_out, len + 4); + msg_out_size = len + 4; + + xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE); + xdr_uint32_t (&xdr, &len); + + r = send_to_daemon (g, msg_out, msg_out_size); + + /* Did the daemon send a cancellation message? */ + if (r == -2) { + if (g->verbose) + fprintf (stderr, "got daemon cancellation\n"); + return -2; + } + + if (r == -1) + goto cleanup1; + + free (msg_out); + + return 0; + + cleanup1: + free (msg_out); + return -1; +} + +/* Receive a reply. */ +int +guestfs___recv (guestfs_h *g, const char *fn, + guestfs_message_header *hdr, + guestfs_message_error *err, + xdrproc_t xdrp, char *ret) +{ + XDR xdr; + void *buf; + uint32_t size; + int r; + + again: + r = recv_from_daemon (g, &size, &buf); + if (r == -1) + return -1; + + /* This can happen if a cancellation happens right at the end + * of us sending a FileIn parameter to the daemon. Discard. The + * daemon should send us an error message next. + */ + if (size == GUESTFS_CANCEL_FLAG) + goto again; + + if (size == GUESTFS_LAUNCH_FLAG) { + error (g, "%s: received unexpected launch flag from daemon when expecting reply", fn); + return -1; + } + + xdrmem_create (&xdr, buf, size, XDR_DECODE); + + if (!xdr_guestfs_message_header (&xdr, hdr)) { + error (g, "%s: failed to parse reply header", fn); + xdr_destroy (&xdr); + free (buf); + return -1; + } + if (hdr->status == GUESTFS_STATUS_ERROR) { + if (!xdr_guestfs_message_error (&xdr, err)) { + error (g, "%s: failed to parse reply error", fn); + xdr_destroy (&xdr); + free (buf); + return -1; + } + } else { + if (xdrp && ret && !xdrp (&xdr, ret)) { + error (g, "%s: failed to parse reply", fn); + xdr_destroy (&xdr); + free (buf); return -1; } + } + xdr_destroy (&xdr); + free (buf); - perrorf (g, "read"); + return 0; +} + +/* Receive a file. */ + +/* Returns -1 = error, 0 = EOF, > 0 = more data */ +static ssize_t receive_file_data (guestfs_h *g, void **buf); + +int +guestfs___recv_file (guestfs_h *g, const char *filename) +{ + void *buf; + int fd, r; + + fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666); + if (fd == -1) { + perrorf (g, "open: %s", filename); + goto cancel; + } + + /* Receive the file in chunked encoding. */ + while ((r = receive_file_data (g, &buf)) > 0) { + if (xwrite (fd, buf, r) == -1) { + perrorf (g, "%s: write", filename); + free (buf); + goto cancel; + } + free (buf); + } + + if (r == -1) { + error (g, _("%s: error in chunked encoding"), filename); + return -1; + } + + if (close (fd) == -1) { + perrorf (g, "close: %s", filename); return -1; } return 0; + + cancel: ; + /* Send cancellation message to daemon, then wait until it + * cancels (just throwing away data). + */ + XDR xdr; + char fbuf[4]; + uint32_t flag = GUESTFS_CANCEL_FLAG; + + if (g->verbose) + fprintf (stderr, "%s: waiting for daemon to acknowledge cancellation\n", + __func__); + + xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE); + xdr_uint32_t (&xdr, &flag); + xdr_destroy (&xdr); + + if (xwrite (g->sock, fbuf, sizeof fbuf) == -1) { + perrorf (g, _("write to daemon socket")); + return -1; + } + + while (receive_file_data (g, NULL) > 0) + ; /* just discard it */ + + return -1; } -void -guestfs_kill_subprocess (guestfs_h *g) +/* Receive a chunk of file data. */ +/* Returns -1 = error, 0 = EOF, > 0 = more data */ +static ssize_t +receive_file_data (guestfs_h *g, void **buf_r) { - if (g->pid >= 0) { - if (g->verbose) - fprintf (stderr, "sending SIGTERM to pgid %d\n", g->pid); + int r; + void *buf; + uint32_t len; + XDR xdr; + guestfs_chunk chunk; + + r = recv_from_daemon (g, &len, &buf); + if (r == -1) { + error (g, _("receive_file_data: parse error in reply callback")); + return -1; + } + + if (len == GUESTFS_LAUNCH_FLAG || len == GUESTFS_CANCEL_FLAG) { + error (g, _("receive_file_data: unexpected flag received when reading file chunks")); + return -1; + } - kill (- g->pid, SIGTERM); - wait_subprocess (g); + memset (&chunk, 0, sizeof chunk); + + xdrmem_create (&xdr, buf, len, XDR_DECODE); + if (!xdr_guestfs_chunk (&xdr, &chunk)) { + error (g, _("failed to parse file chunk")); + free (buf); + return -1; + } + xdr_destroy (&xdr); + /* After decoding, the original buffer is no longer used. */ + free (buf); + + if (chunk.cancel) { + error (g, _("file receive cancelled by daemon")); + free (chunk.data.data_val); + return -1; + } + + if (chunk.data.data_len == 0) { /* end of transfer */ + free (chunk.data.data_val); + return 0; } - cleanup_fds (g); + if (buf_r) *buf_r = chunk.data.data_val; + else free (chunk.data.data_val); /* else caller frees */ + + return chunk.data.data_len; }