X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fguestfsd.c;h=e3b8883eb2c2c472fe038f0bd2677234c28ea521;hp=eeb84bd1c29f738e4e09e8fddef7fb462b984e39;hb=8b217a87bf9175e7e02a5913e5617e0d12dfd09c;hpb=427b5f079fd344919ecf568bab2084825aacf606 diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index eeb84bd..e3b8883 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -1,5 +1,5 @@ /* libguestfs - the guestfsd daemon - * Copyright (C) 2009 Red Hat Inc. + * Copyright (C) 2009 Red Hat Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -32,59 +32,89 @@ #include #include #include +#include +#include #include #include +#include #include "daemon.h" -static void usage (void); +static char *read_cmdline (void); /* Also in guestfs.c */ -#define VMCHANNEL_PORT "6666" -#define VMCHANNEL_ADDR "10.0.2.4" +#define GUESTFWD_ADDR "10.0.2.4" +#define GUESTFWD_PORT "6666" int verbose = 0; +static int print_shell_quote (FILE *stream, const struct printf_info *info, const void *const *args); +static int print_sysroot_shell_quote (FILE *stream, const struct printf_info *info, const void *const *args); +#ifdef HAVE_REGISTER_PRINTF_SPECIFIER +static int print_arginfo (const struct printf_info *info, size_t n, int *argtypes, int *size); +#else +#ifdef HAVE_REGISTER_PRINTF_FUNCTION +static int print_arginfo (const struct printf_info *info, size_t n, int *argtypes); +#else +#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined" +#endif +#endif + +/* Location to mount root device. */ +const char *sysroot = "/sysroot"; /* No trailing slash. */ +int sysroot_len = 8; + +static void +usage (void) +{ + fprintf (stderr, + "guestfsd [-f|--foreground] [-c|--channel vmchannel] [-v|--verbose]\n"); +} + int main (int argc, char *argv[]) { - static const char *options = "fh:p:?"; - static struct option long_options[] = { + static const char *options = "fc:v?"; + static const struct option long_options[] = { + { "channel", required_argument, 0, 'c' }, { "foreground", 0, 0, 'f' }, { "help", 0, 0, '?' }, - { "host", 1, 0, 'h' }, - { "port", 1, 0, 'p' }, + { "verbose", 0, 0, 'v' }, { 0, 0, 0, 0 } }; - int c, n, r; + int c; int dont_fork = 0; - const char *host = NULL; - const char *port = NULL; - FILE *fp; - char buf[4096]; - char *p, *p2; - int sock; - struct addrinfo *res, *rr; - struct addrinfo hints; - XDR xdr; - uint32_t len; - struct sigaction sa; + char *cmdline; + char *vmchannel = NULL; + +#ifdef HAVE_REGISTER_PRINTF_SPECIFIER + /* http://udrepper.livejournal.com/20948.html */ + register_printf_specifier ('Q', print_shell_quote, print_arginfo); + register_printf_specifier ('R', print_sysroot_shell_quote, print_arginfo); +#else +#ifdef HAVE_REGISTER_PRINTF_FUNCTION + register_printf_function ('Q', print_shell_quote, print_arginfo); + register_printf_function ('R', print_sysroot_shell_quote, print_arginfo); +#else +#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined" +#endif +#endif for (;;) { c = getopt_long (argc, argv, options, long_options, NULL); if (c == -1) break; switch (c) { - case 'f': - dont_fork = 1; + case 'c': + vmchannel = optarg; break; - case 'h': - host = optarg; + case 'f': + dont_fork = 1; break; - case 'p': - port = optarg; + case 'v': + verbose = 1; break; case '?': @@ -102,95 +132,177 @@ main (int argc, char *argv[]) exit (1); } - /* If host and port aren't set yet, try /proc/cmdline. */ - if (!host || !port) { - fp = fopen ("/proc/cmdline", "r"); - if (fp == NULL) { - perror ("/proc/cmdline"); - goto next; - } - n = fread (buf, 1, sizeof buf - 1, fp); - fclose (fp); - buf[n] = '\0'; - - /* Set the verbose flag. Not quite right because this will only - * set the flag if host and port aren't set on the command line. - * Don't worry about this for now. (XXX) - */ - verbose = strstr (buf, "guestfs_verbose=1") != NULL; - if (verbose) - printf ("verbose daemon enabled\n"); + cmdline = read_cmdline (); - p = strstr (buf, "guestfs="); - - if (p) { - p += 8; - p2 = strchr (p, ':'); - if (p2) { - *p2++ = '\0'; - host = p; - r = strcspn (p2, " \n"); - p2[r] = '\0'; - port = p2; - } - } - } + /* Set the verbose flag. */ + verbose = verbose || + (cmdline && strstr (cmdline, "guestfs_verbose=1") != NULL); + if (verbose) + printf ("verbose daemon enabled\n"); - next: - /* Can't parse /proc/cmdline, so use built-in defaults. */ - if (!host || !port) { - host = VMCHANNEL_ADDR; - port = VMCHANNEL_PORT; + if (verbose) { + if (cmdline) + printf ("linux commmand line: %s\n", cmdline); + else + printf ("could not read linux command line\n"); } /* Make sure SIGPIPE doesn't kill us. */ + struct sigaction sa; memset (&sa, 0, sizeof sa); sa.sa_handler = SIG_IGN; sa.sa_flags = 0; if (sigaction (SIGPIPE, &sa, NULL) == -1) perror ("sigaction SIGPIPE"); /* but try to continue anyway ... */ - /* Resolve the hostname. */ - memset (&hints, 0, sizeof hints); - hints.ai_socktype = SOCK_STREAM; - hints.ai_flags = AI_ADDRCONFIG; - r = getaddrinfo (host, port, &hints, &res); - if (r != 0) { - fprintf (stderr, "%s:%s: %s\n", host, port, gai_strerror (r)); - exit (1); + /* Set up a basic environment. After we are called by /init the + * environment is essentially empty. + * https://bugzilla.redhat.com/show_bug.cgi?id=502074#c5 + */ + setenv ("PATH", "/usr/bin:/bin", 1); + setenv ("SHELL", "/bin/sh", 1); + setenv ("LC_ALL", "C", 1); + + /* We document that umask defaults to 022 (it should be this anyway). */ + umask (022); + + /* Get the vmchannel string. + * + * Sources: + * --channel/-c option on the command line + * guestfs_vmchannel=... from the kernel command line + * guestfs=... from the kernel command line + * built-in default + * + * At the moment we expect this to contain "tcp:ip:port" but in + * future it might contain a device name, eg. "/dev/vcon4" for + * virtio-console vmchannel. + */ + if (vmchannel == NULL && cmdline) { + char *p; + size_t len; + + p = strstr (cmdline, "guestfs_vmchannel="); + if (p) { + len = strcspn (p + 18, " \t\n"); + vmchannel = strndup (p + 18, len); + if (!vmchannel) { + perror ("strndup"); + exit (1); + } + } + + /* Old libraries passed guestfs=host:port. Rewrite it as tcp:host:port. */ + if (vmchannel == NULL) { + /* We will rewrite it part of the "guestfs=" string with + * "tcp:" hence p + 4 below. */ + p = strstr (cmdline, "guestfs="); + if (p) { + len = strcspn (p + 4, " \t\n"); + vmchannel = strndup (p + 4, len); + if (!vmchannel) { + perror ("strndup"); + exit (1); + } + memcpy (vmchannel, "tcp:", 4); + } + } } - /* Connect to the given TCP socket. */ - sock = -1; - for (rr = res; rr != NULL; rr = rr->ai_next) { - sock = socket (rr->ai_family, rr->ai_socktype, rr->ai_protocol); - if (sock != -1) { - if (connect (sock, rr->ai_addr, rr->ai_addrlen) == 0) - break; - perror ("connect"); + /* Default vmchannel. */ + if (vmchannel == NULL) { + vmchannel = strdup ("tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT); + if (!vmchannel) { + perror ("strdup"); + exit (1); + } + } + + if (verbose) + printf ("vmchannel: %s\n", vmchannel); + + /* Connect to vmchannel. */ + int sock = -1; - close (sock); - sock = -1; + if (strncmp (vmchannel, "tcp:", 4) == 0) { + /* Resolve the hostname. */ + struct addrinfo *res, *rr; + struct addrinfo hints; + int r; + char *host, *port; + + host = vmchannel+4; + port = strchr (host, ':'); + if (port) { + port[0] = '\0'; + port++; + } else { + fprintf (stderr, "vmchannel: expecting \"tcp::\": %s\n", + vmchannel); + exit (1); + } + + memset (&hints, 0, sizeof hints); + hints.ai_socktype = SOCK_STREAM; + hints.ai_flags = AI_ADDRCONFIG; + r = getaddrinfo (host, port, &hints, &res); + if (r != 0) { + fprintf (stderr, "%s:%s: %s\n", + host, port, gai_strerror (r)); + exit (1); + } + + /* Connect to the given TCP socket. */ + for (rr = res; rr != NULL; rr = rr->ai_next) { + sock = socket (rr->ai_family, rr->ai_socktype, rr->ai_protocol); + if (sock != -1) { + if (connect (sock, rr->ai_addr, rr->ai_addrlen) == 0) + break; + perror ("connect"); + + close (sock); + sock = -1; + } } + freeaddrinfo (res); + } else { + fprintf (stderr, + "unknown vmchannel connection type: %s\n" + "expecting \"tcp::\"\n", + vmchannel); + exit (1); } - freeaddrinfo (res); if (sock == -1) { - fprintf (stderr, "connection to %s:%s failed\n", host, port); + fprintf (stderr, + "\n" + "Failed to connect to any vmchannel implementation.\n" + "vmchannel: %s\n" + "\n" + "This is a fatal error and the appliance will now exit.\n" + "\n" + "Usually this error is caused by either QEMU or the appliance\n" + "kernel not supporting the vmchannel method that the\n" + "libguestfs library chose to use. Please run\n" + "'libguestfs-test-tool' and provide the complete, unedited\n" + "output to the libguestfs developers, either in a bug report\n" + "or on the libguestfs redhat com mailing list.\n" + "\n", + vmchannel); exit (1); } /* Send the magic length message which indicates that * userspace is up inside the guest. */ - len = GUESTFS_LAUNCH_FLAG; - xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE); - if (!xdr_uint32_t (&xdr, &len)) { - fprintf (stderr, "xdr_uint32_t failed\n"); - exit (1); - } + char lenbuf[4]; + XDR xdr; + uint32_t len = GUESTFS_LAUNCH_FLAG; + xdrmem_create (&xdr, lenbuf, sizeof lenbuf, XDR_ENCODE); + xdr_uint32_t (&xdr, &len); - (void) xwrite (sock, buf, xdr_getpos (&xdr)); + if (xwrite (sock, lenbuf, sizeof lenbuf) == -1) + exit (1); xdr_destroy (&xdr); @@ -208,10 +320,81 @@ main (int argc, char *argv[]) exit (0); } +/* Read /proc/cmdline. */ +static char * +read_cmdline (void) +{ + int fd = open ("/proc/cmdline", O_RDONLY); + if (fd == -1) { + perror ("/proc/cmdline"); + return NULL; + } + + size_t len = 0; + ssize_t n; + char buf[256]; + char *r = NULL; + + for (;;) { + n = read (fd, buf, sizeof buf); + if (n == -1) { + perror ("read"); + free (r); + close (fd); + return NULL; + } + if (n == 0) + break; + char *newr = realloc (r, len + n + 1); /* + 1 is for terminating NUL */ + if (newr == NULL) { + perror ("realloc"); + free (r); + close (fd); + return NULL; + } + r = newr; + memcpy (&r[len], buf, n); + len += n; + } + + if (r) + r[len] = '\0'; + + if (close (fd) == -1) { + perror ("close"); + free (r); + return NULL; + } + + return r; +} + +/* Turn "/path" into "/sysroot/path". + * + * Caller must check for NULL and call reply_with_perror ("malloc") + * if it is. Caller must also free the string. + * + * See also the custom %R printf formatter which does shell quoting too. + */ +char * +sysroot_path (const char *path) +{ + char *r; + int len = strlen (path) + sysroot_len + 1; + + r = malloc (len); + if (r == NULL) + return NULL; + + snprintf (r, len, "%s%s", sysroot, path); + return r; +} + int -xwrite (int sock, const void *buf, size_t len) +xwrite (int sock, const void *v_buf, size_t len) { int r; + const char *buf = v_buf; while (len > 0) { r = write (sock, buf, len); @@ -227,9 +410,10 @@ xwrite (int sock, const void *buf, size_t len) } int -xread (int sock, void *buf, size_t len) +xread (int sock, void *v_buf, size_t len) { int r; + char *buf = v_buf; while (len > 0) { r = read (sock, buf, len); @@ -248,12 +432,6 @@ xread (int sock, void *buf, size_t len) return 0; } -static void -usage (void) -{ - fprintf (stderr, "guestfsd [-f] [-h host -p port]\n"); -} - int add_string (char ***argv, int *size, int *alloc, const char *str) { @@ -287,7 +465,7 @@ add_string (char ***argv, int *size, int *alloc, const char *str) } int -count_strings (char * const* const argv) +count_strings (char *const *argv) { int argc; @@ -339,7 +517,7 @@ int command (char **stdoutput, char **stderror, const char *name, ...) { va_list args; - char **argv, **p; + const char **argv; char *s; int i, r; @@ -356,7 +534,7 @@ command (char **stdoutput, char **stderror, const char *name, ...) va_start (args, name); while ((s = va_arg (args, char *)) != NULL) { - p = realloc (argv, sizeof (char *) * (++i)); + const char **p = realloc (argv, sizeof (char *) * (++i)); if (p == NULL) { perror ("realloc"); free (argv); @@ -370,7 +548,7 @@ command (char **stdoutput, char **stderror, const char *name, ...) va_end (args); - r = commandv (stdoutput, stderror, argv); + r = commandv (stdoutput, stderror, (char **) argv); /* NB: Mustn't free the strings which are on the stack. */ free (argv); @@ -386,7 +564,7 @@ int commandr (char **stdoutput, char **stderror, const char *name, ...) { va_list args; - char **argv, **p; + const char **argv; char *s; int i, r; @@ -403,7 +581,7 @@ commandr (char **stdoutput, char **stderror, const char *name, ...) va_start (args, name); while ((s = va_arg (args, char *)) != NULL) { - p = realloc (argv, sizeof (char *) * (++i)); + const char **p = realloc (argv, sizeof (char *) * (++i)); if (p == NULL) { perror ("realloc"); free (argv); @@ -427,11 +605,11 @@ commandr (char **stdoutput, char **stderror, const char *name, ...) /* Same as 'command', but passing an argv. */ int -commandv (char **stdoutput, char **stderror, char * const* const argv) +commandv (char **stdoutput, char **stderror, char *const *argv) { int r; - r = commandrv (stdoutput, stderror, argv); + r = commandrv (stdoutput, stderror, (void *) argv); if (r == 0) return 0; else @@ -439,11 +617,12 @@ commandv (char **stdoutput, char **stderror, char * const* const argv) } int -commandrv (char **stdoutput, char **stderror, char * const* const argv) +commandrv (char **stdoutput, char **stderror, char const* const *argv) { int so_size = 0, se_size = 0; int so_fd[2], se_fd[2]; - int pid, r, quit, i; + pid_t pid; + int r, quit, i; fd_set rset, rset2; char buf[256]; char *p; @@ -482,7 +661,7 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv) close (so_fd[1]); close (se_fd[1]); - execvp (argv[0], argv); + execvp (argv[0], (void *) argv); perror (argv[0]); _exit (1); } @@ -513,40 +692,40 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv) if (FD_ISSET (so_fd[0], &rset2)) { /* something on stdout */ r = read (so_fd[0], buf, sizeof buf); if (r == -1) { - perror ("read"); - goto quit; + perror ("read"); + goto quit; } if (r == 0) { FD_CLR (so_fd[0], &rset); quit++; } if (r > 0 && stdoutput) { - so_size += r; - p = realloc (*stdoutput, so_size); - if (p == NULL) { - perror ("realloc"); - goto quit; - } - *stdoutput = p; - memcpy (*stdoutput + so_size - r, buf, r); + so_size += r; + p = realloc (*stdoutput, so_size); + if (p == NULL) { + perror ("realloc"); + goto quit; + } + *stdoutput = p; + memcpy (*stdoutput + so_size - r, buf, r); } } if (FD_ISSET (se_fd[0], &rset2)) { /* something on stderr */ r = read (se_fd[0], buf, sizeof buf); if (r == -1) { - perror ("read"); - goto quit; + perror ("read"); + goto quit; } if (r == 0) { FD_CLR (se_fd[0], &rset); quit++; } if (r > 0 && stderror) { - se_size += r; - p = realloc (*stderror, se_size); - if (p == NULL) { - perror ("realloc"); - goto quit; - } - *stderror = p; - memcpy (*stderror + se_size - r, buf, r); + se_size += r; + p = realloc (*stderror, se_size); + if (p == NULL) { + perror ("realloc"); + goto quit; + } + *stderror = p; + memcpy (*stderror + se_size - r, buf, r); } } } @@ -558,28 +737,35 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv) * trailing \n characters from the error buffer (not from stdout). */ if (stdoutput) { - *stdoutput = realloc (*stdoutput, so_size+1); - if (*stdoutput == NULL) { + void *q = realloc (*stdoutput, so_size+1); + if (q == NULL) { perror ("realloc"); - *stdoutput = NULL; - } else + free (*stdoutput); + } + *stdoutput = q; + if (*stdoutput) (*stdoutput)[so_size] = '\0'; } if (stderror) { - *stderror = realloc (*stderror, se_size+1); - if (*stderror == NULL) { + void *q = realloc (*stderror, se_size+1); + if (q == NULL) { perror ("realloc"); - *stderror = NULL; - } else { + free (*stderror); + } + *stderror = q; + if (*stderror) { (*stderror)[se_size] = '\0'; se_size--; while (se_size >= 0 && (*stderror)[se_size] == '\n') - (*stderror)[se_size--] = '\0'; + (*stderror)[se_size--] = '\0'; } } /* Get the exit status of the command. */ - waitpid (pid, &r, 0); + if (waitpid (pid, &r, 0) != pid) { + perror ("waitpid"); + return -1; + } if (WIFEXITED (r)) { return WEXITSTATUS (r); @@ -587,39 +773,175 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv) return -1; } -/* Quote 'in' for the shell, and write max len-1 bytes to out. The - * result will be NUL-terminated, even if it is truncated. +/* Split an output string into a NULL-terminated list of lines. + * Typically this is used where we have run an external command + * which has printed out a list of things, and we want to return + * an actual list. * - * Returns number of bytes needed, so if result >= len then the buffer - * should have been longer. + * The corner cases here are quite tricky. Note in particular: * - * XXX This doesn't quote \n correctly (but is still safe). + * "" -> [] + * "\n" -> [""] + * "a\nb" -> ["a"; "b"] + * "a\nb\n" -> ["a"; "b"] + * "a\nb\n\n" -> ["a"; "b"; ""] + * + * The original string is written over and destroyed by this + * function (which is usually OK because it's the 'out' string + * from command()). You can free the original string, because + * add_string() strdups the strings. */ -int -shell_quote (char *out, int len, const char *in) +char ** +split_lines (char *str) +{ + char **lines = NULL; + int size = 0, alloc = 0; + char *p, *pend; + + if (strcmp (str, "") == 0) + goto empty_list; + + p = str; + while (p) { + /* Empty last line? */ + if (p[0] == '\0') + break; + + pend = strchr (p, '\n'); + if (pend) { + *pend = '\0'; + pend++; + } + + if (add_string (&lines, &size, &alloc, p) == -1) { + return NULL; + } + + p = pend; + } + + empty_list: + if (add_string (&lines, &size, &alloc, NULL) == -1) + return NULL; + + return lines; +} + +/* printf helper function so we can use %Q ("quoted") and %R to print + * shell-quoted strings. See HACKING file for more details. + */ +static int +print_shell_quote (FILE *stream, + const struct printf_info *info ATTRIBUTE_UNUSED, + const void *const *args) { #define SAFE(c) (isalnum((c)) || \ - (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.') - int i, j; - int outlen = strlen (in); + (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.') + int i, len; + const char *str = *((const char **) (args[0])); + + for (i = len = 0; str[i]; ++i) { + if (!SAFE(str[i])) { + putc ('\\', stream); + len ++; + } + putc (str[i], stream); + len ++; + } - /* Calculate how much output space this really needs. */ - for (i = 0; in[i]; ++i) - if (!SAFE (in[i])) outlen++; + return len; +} - /* Now copy the string, but only up to len-1 bytes. */ - for (i = 0, j = 0; in[i]; ++i) { - int is_safe = SAFE (in[i]); +static int +print_sysroot_shell_quote (FILE *stream, + const struct printf_info *info, + const void *const *args) +{ + fputs (sysroot, stream); + return sysroot_len + print_shell_quote (stream, info, args); +} - /* Enough space left to write this character? */ - if (j >= len-1 || (!is_safe && j >= len-2)) - break; +#ifdef HAVE_REGISTER_PRINTF_SPECIFIER +static int +print_arginfo (const struct printf_info *info ATTRIBUTE_UNUSED, + size_t n, int *argtypes, int *size) +{ + if (n > 0) { + argtypes[0] = PA_STRING; + size[0] = sizeof (const char *); + } + return 1; +} +#else +#ifdef HAVE_REGISTER_PRINTF_FUNCTION +static int +print_arginfo (const struct printf_info *info, size_t n, int *argtypes) +{ + if (n > 0) + argtypes[0] = PA_STRING; + return 1; +} +#else +#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined" +#endif +#endif - if (!is_safe) out[j++] = '\\'; - out[j++] = in[i]; +/* Perform device name translation. Don't call this directly - + * use the RESOLVE_DEVICE macro. + * + * See guestfs(3) for the algorithm. + * + * We have to open the device and test for ENXIO, because + * the device nodes themselves will exist in the appliance. + */ +int +device_name_translation (char *device, const char *func) +{ + int fd; + + fd = open (device, O_RDONLY); + if (fd >= 0) { + close (fd); + return 0; } - out[j] = '\0'; + if (errno != ENXIO && errno != ENOENT) { + error: + reply_with_perror ("%s: %s", func, device); + return -1; + } + + /* If the name begins with "/dev/sd" then try the alternatives. */ + if (strncmp (device, "/dev/sd", 7) != 0) + goto error; + + device[5] = 'h'; /* /dev/hd (old IDE driver) */ + fd = open (device, O_RDONLY); + if (fd >= 0) { + close (fd); + return 0; + } - return outlen; + device[5] = 'v'; /* /dev/vd (for virtio devices) */ + fd = open (device, O_RDONLY); + if (fd >= 0) { + close (fd); + return 0; + } + + device[5] = 's'; /* Restore original device name. */ + goto error; +} + +/* LVM and other commands aren't synchronous, especially when udev is + * involved. eg. You can create or remove some device, but the /dev + * device node won't appear until some time later. This means that + * you get an error if you run one command followed by another. + * Use 'udevadm settle' after certain commands, but don't be too + * fussed if it fails. + */ +void +udev_settle (void) +{ + command (NULL, NULL, "/sbin/udevadm", "settle", NULL); }