X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fguestfsd.c;h=e398b7d8348410fad052a94ebe27bde014e4b0a9;hp=bfd8139241ab0c5b0ae0632f2cb1d29619c1d186;hb=4d900cdac8258daa2e99c6ceb2a4985154e94150;hpb=da0a4f8d1f6ddd302ceba028d87c6e009589e503 diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index bfd8139..e398b7d 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) 2009-2010 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 @@ -20,6 +20,10 @@ #define _BSD_SOURCE /* for daemon(3) */ +#ifdef HAVE_WINDOWS_H +# include +#endif + #include #include #include @@ -27,24 +31,45 @@ #include #include #include -#include #include -#include #include -#include #include #include -#include #include -#include +#include +#include +#include +#include +#include +#include + +#ifdef HAVE_PRINTF_H +# include +#endif + +#include "sockets.h" +#include "c-ctype.h" +#include "ignore-value.h" +#include "error.h" #include "daemon.h" -static void usage (void); +static char *read_cmdline (void); + +#ifndef MAX +# define MAX(a,b) ((a)>(b)?(a):(b)) +#endif + +/* Not the end of the world if this open flag is not defined. */ +#ifndef O_CLOEXEC +# define O_CLOEXEC 0 +#endif -/* Also in guestfs.c */ -#define GUESTFWD_PORT "6666" -#define GUESTFWD_ADDR "10.0.2.4" +/* If root device is an ext2 filesystem, this is the major and minor. + * This is so we can ignore this device from the point of view of the + * user, eg. in guestfs_list_devices and many other places. + */ +static dev_t root_device = 0; int verbose = 0; @@ -60,30 +85,65 @@ static int print_arginfo (const struct printf_info *info, size_t n, int *argtype #endif #endif +#ifdef WIN32 +static int +daemon (int nochdir, int noclose) +{ + fprintf (stderr, + "On Windows the daemon does not support forking into the " + "background.\nYou *must* run the daemon with the -f option.\n"); + exit (EXIT_FAILURE); +} +#endif /* WIN32 */ + +#ifdef WIN32 +static int +winsock_init (void) +{ + int r; + + /* http://msdn2.microsoft.com/en-us/library/ms742213.aspx */ + r = gl_sockets_startup (SOCKETS_2_2); + return r == 0 ? 0 : -1; +} +#else /* !WIN32 */ +static int +winsock_init (void) +{ + return 0; +} +#endif /* !WIN32 */ + /* Location to mount root device. */ const char *sysroot = "/sysroot"; /* No trailing slash. */ int sysroot_len = 8; +/* Not used explicitly, but required by the gnulib 'error' module. */ +const char *program_name = "guestfsd"; + +static void +usage (void) +{ + fprintf (stderr, + "guestfsd [-f|--foreground] [-v|--verbose]\n"); +} + int main (int argc, char *argv[]) { - static const char *options = "f?"; + static const char *options = "fv?"; static const struct option long_options[] = { { "foreground", 0, 0, 'f' }, { "help", 0, 0, '?' }, + { "verbose", 0, 0, 'v' }, { 0, 0, 0, 0 } }; - int c, n, r; + int c; int dont_fork = 0; - 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; + + if (winsock_init () == -1) + error (EXIT_FAILURE, 0, "winsock initialization failed"); #ifdef HAVE_REGISTER_PRINTF_SPECIFIER /* http://udrepper.livejournal.com/20948.html */ @@ -98,6 +158,10 @@ main (int argc, char *argv[]) #endif #endif + struct stat statbuf; + if (stat ("/", &statbuf) == 0) + root_device = statbuf.st_dev; + for (;;) { c = getopt_long (argc, argv, options, long_options, NULL); if (c == -1) break; @@ -107,98 +171,107 @@ main (int argc, char *argv[]) dont_fork = 1; break; + case 'v': + verbose = 1; + break; + case '?': usage (); - exit (0); + exit (EXIT_SUCCESS); default: fprintf (stderr, "guestfsd: unexpected command line option 0x%x\n", c); - exit (1); + exit (EXIT_FAILURE); } } if (optind < argc) { usage (); - exit (1); + exit (EXIT_FAILURE); } - /* Set the verbose flag. */ - 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'; + cmdline = read_cmdline (); - verbose = strstr (buf, "guestfs_verbose=1") != NULL; + /* Set the verbose flag. */ + verbose = verbose || + (cmdline && strstr (cmdline, "guestfs_verbose=1") != NULL); if (verbose) printf ("verbose daemon enabled\n"); - next: + if (verbose) { + if (cmdline) + printf ("linux commmand line: %s\n", cmdline); + else + printf ("could not read linux command line\n"); + } + +#ifndef WIN32 /* 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 ... */ +#endif +#ifdef WIN32 +# define setenv(n,v,f) _putenv(n "=" v) +#endif /* 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 + * + * NOTE: if you change $PATH, you must also change 'prog_exists' + * function below. */ - setenv ("PATH", "/usr/bin:/bin", 1); + setenv ("PATH", "/sbin:/usr/sbin:/bin:/usr/bin", 1); setenv ("SHELL", "/bin/sh", 1); setenv ("LC_ALL", "C", 1); + setenv ("TERM", "dumb", 1); +#ifndef WIN32 /* We document that umask defaults to 022 (it should be this anyway). */ umask (022); +#else + /* This is the default for Windows anyway. It's not even clear if + * Windows ever uses this -- the MSDN documentation for the function + * contains obvious errors. + */ + _umask (0); +#endif - /* Resolve the hostname. */ - memset (&hints, 0, sizeof hints); - hints.ai_socktype = SOCK_STREAM; - hints.ai_flags = AI_ADDRCONFIG; - r = getaddrinfo (GUESTFWD_ADDR, GUESTFWD_PORT, &hints, &res); - if (r != 0) { - fprintf (stderr, "%s:%s: %s\n", - GUESTFWD_ADDR, GUESTFWD_PORT, gai_strerror (r)); - exit (1); - } - - /* 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"); - - close (sock); - sock = -1; - } - } - freeaddrinfo (res); - + /* Connect to virtio-serial channel. */ + int sock = open ("/dev/virtio-ports/org.libguestfs.channel.0", + O_RDWR | O_CLOEXEC); if (sock == -1) { - fprintf (stderr, "connection to %s:%s failed\n", - GUESTFWD_ADDR, GUESTFWD_PORT); - exit (1); + fprintf (stderr, + "\n" + "Failed to connect to virtio-serial channel.\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"); + exit (EXIT_FAILURE); } /* 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_u_int (&xdr, &len); - if (xwrite (sock, buf, xdr_getpos (&xdr)) == -1) - exit (1); + if (xwrite (sock, lenbuf, sizeof lenbuf) == -1) + exit (EXIT_FAILURE); xdr_destroy (&xdr); @@ -206,14 +279,79 @@ main (int argc, char *argv[]) if (!dont_fork) { if (daemon (0, 1) == -1) { perror ("daemon"); - exit (1); + exit (EXIT_FAILURE); } } /* Enter the main loop, reading and performing actions. */ main_loop (sock); - exit (0); + exit (EXIT_SUCCESS); +} + +/* 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; +} + +/* Return true iff device is the root device (and therefore should be + * ignored from the point of view of user calls). + */ +int +is_root_device (const char *device) +{ + struct stat statbuf; + if (stat (device, &statbuf) == -1) { + perror (device); + return 0; + } + if (statbuf.st_rdev == root_device) + return 1; + return 0; } /* Turn "/path" into "/sysroot/path". @@ -279,12 +417,6 @@ xread (int sock, void *v_buf, size_t len) return 0; } -static void -usage (void) -{ - fprintf (stderr, "guestfsd [-f]\n"); -} - int add_string (char ***argv, int *size, int *alloc, const char *str) { @@ -317,16 +449,23 @@ add_string (char ***argv, int *size, int *alloc, const char *str) return 0; } -int +size_t count_strings (char *const *argv) { - int argc; + size_t argc; for (argc = 0; argv[argc] != NULL; ++argc) ; return argc; } +/* http://graphics.stanford.edu/~seander/bithacks.html#DetermineIfPowerOf2 */ +int +is_power_of_2 (unsigned long v) +{ + return v && ((v & (v - 1)) == 0); +} + static int compare (const void *vp1, const void *vp2) { @@ -361,13 +500,11 @@ free_stringslen (char **argv, int len) free (argv); } -/* This is a more sane version of 'system(3)' for running external - * commands. It uses fork/execvp, so we don't need to worry about - * quoting of parameters, and it allows us to capture any error - * messages in a buffer. +/* Easy ways to run external commands. For full documentation, see + * 'commandrvf' below. */ int -command (char **stdoutput, char **stderror, const char *name, ...) +commandf (char **stdoutput, char **stderror, int flags, const char *name, ...) { va_list args; const char **argv; @@ -401,7 +538,7 @@ command (char **stdoutput, char **stderror, const char *name, ...) va_end (args); - r = commandv (stdoutput, stderror, (char **) argv); + r = commandvf (stdoutput, stderror, flags, (const char * const*) argv); /* NB: Mustn't free the strings which are on the stack. */ free (argv); @@ -414,7 +551,7 @@ command (char **stdoutput, char **stderror, const char *name, ...) * We still return -1 if there was some other error. */ int -commandr (char **stdoutput, char **stderror, const char *name, ...) +commandrf (char **stdoutput, char **stderror, int flags, const char *name, ...) { va_list args; const char **argv; @@ -448,7 +585,7 @@ commandr (char **stdoutput, char **stderror, const char *name, ...) va_end (args); - r = commandrv (stdoutput, stderror, argv); + r = commandrvf (stdoutput, stderror, flags, argv); /* NB: Mustn't free the strings which are on the stack. */ free (argv); @@ -458,23 +595,57 @@ commandr (char **stdoutput, char **stderror, const char *name, ...) /* Same as 'command', but passing an argv. */ int -commandv (char **stdoutput, char **stderror, char *const *argv) +commandvf (char **stdoutput, char **stderror, int flags, + char const *const *argv) { int r; - r = commandrv (stdoutput, stderror, (void *) argv); + r = commandrvf (stdoutput, stderror, flags, (void *) argv); if (r == 0) return 0; else return -1; } +/* This is a more sane version of 'system(3)' for running external + * commands. It uses fork/execvp, so we don't need to worry about + * quoting of parameters, and it allows us to capture any error + * messages in a buffer. + * + * If stdoutput is not NULL, then *stdoutput will return the stdout + * of the command. + * + * If stderror is not NULL, then *stderror will return the stderr + * of the command. If there is a final \n character, it is removed + * so you can use the error string directly in a call to + * reply_with_error. + * + * Flags: + * + * COMMAND_FLAG_FOLD_STDOUT_ON_STDERR: For broken external commands + * that send error messages to stdout (hello, parted) but that don't + * have any useful stdout information, use this flag to capture the + * error messages in the *stderror buffer. If using this flag, + * you should pass stdoutput as NULL because nothing could ever be + * captured in that buffer. + * + * COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN: For running external + * commands on chrooted files correctly (see RHBZ#579608) specifying + * this flag causes another process to be forked which chroots into + * sysroot and just copies the input file to stdin of the specified + * command. The file descriptor is ORed with the flags, and that file + * descriptor is always closed by this function. See hexdump.c for an + * example of usage. + */ int -commandrv (char **stdoutput, char **stderror, char const* const *argv) +commandrvf (char **stdoutput, char **stderror, int flags, + char const* const *argv) { int so_size = 0, se_size = 0; int so_fd[2], se_fd[2]; - pid_t pid; + int flag_copy_stdin = flags & COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN; + int stdin_fd[2] = { -1, -1 }; + pid_t pid, stdin_pid = -1; int r, quit, i; fd_set rset, rset2; char buf[256]; @@ -490,33 +661,110 @@ commandrv (char **stdoutput, char **stderror, char const* const *argv) printf ("\n"); } + /* Note: abort is used in a few places along the error paths early + * in this function. This is because (a) cleaning up correctly is + * very complex at these places and (b) abort is used when a + * resource problems is indicated which would be due to much more + * serious issues - eg. memory or file descriptor leaks. We + * wouldn't expect fork(2) or pipe(2) to fail in normal + * circumstances. + */ + if (pipe (so_fd) == -1 || pipe (se_fd) == -1) { - perror ("pipe"); - return -1; + error (0, errno, "pipe"); + abort (); + } + + if (flag_copy_stdin) { + if (pipe (stdin_fd) == -1) { + error (0, errno, "pipe"); + abort (); + } } pid = fork (); if (pid == -1) { - perror ("fork"); - close (so_fd[0]); - close (so_fd[1]); - close (se_fd[0]); - close (se_fd[1]); - return -1; + error (0, errno, "fork"); + abort (); } - if (pid == 0) { /* Child process. */ + if (pid == 0) { /* Child process running the command. */ close (0); + if (flag_copy_stdin) { + dup2 (stdin_fd[0], 0); + close (stdin_fd[0]); + close (stdin_fd[1]); + } else { + /* Set stdin to /dev/null (ignore failure) */ + open ("/dev/null", O_RDONLY); + } close (so_fd[0]); close (se_fd[0]); - dup2 (so_fd[1], 1); + if (!(flags & COMMAND_FLAG_FOLD_STDOUT_ON_STDERR)) + dup2 (so_fd[1], 1); + else + dup2 (se_fd[1], 1); dup2 (se_fd[1], 2); close (so_fd[1]); close (se_fd[1]); execvp (argv[0], (void *) argv); perror (argv[0]); - _exit (1); + _exit (EXIT_FAILURE); + } + + if (flag_copy_stdin) { + int fd = flags & COMMAND_FLAG_FD_MASK; + + stdin_pid = fork (); + if (stdin_pid == -1) { + error (0, errno, "fork"); + abort (); + } + + if (stdin_pid == 0) { /* Child process copying stdin. */ + close (so_fd[0]); + close (so_fd[1]); + close (se_fd[0]); + close (se_fd[1]); + + close (1); + dup2 (stdin_fd[1], 1); + close (stdin_fd[0]); + close (stdin_fd[1]); + + if (chroot (sysroot) == -1) { + perror ("chroot"); + _exit (EXIT_FAILURE); + } + + ssize_t n; + char buffer[BUFSIZ]; + while ((n = read (fd, buffer, sizeof buffer)) > 0) { + if (xwrite (1, buffer, n) == -1) + /* EPIPE error indicates the command process has exited + * early. If the command process fails that will be caught + * by the daemon, and if not, then it's not an error. + */ + _exit (errno == EPIPE ? EXIT_SUCCESS : EXIT_FAILURE); + } + + if (n == -1) { + perror ("read"); + _exit (EXIT_FAILURE); + } + + if (close (fd) == -1) { + perror ("close"); + _exit (EXIT_FAILURE); + } + + _exit (EXIT_SUCCESS); + } + + close (fd); + close (stdin_fd[0]); + close (stdin_fd[1]); } /* Parent process. */ @@ -539,6 +787,7 @@ commandrv (char **stdoutput, char **stderror, char const* const *argv) close (so_fd[0]); close (se_fd[0]); waitpid (pid, NULL, 0); + if (stdin_pid >= 0) waitpid (stdin_pid, NULL, 0); return -1; } @@ -570,15 +819,20 @@ commandrv (char **stdoutput, char **stderror, char const* const *argv) } 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; + if (r > 0) { + if (verbose) + ignore_value (write (2, buf, r)); + + if (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); } - *stderror = p; - memcpy (*stderror + se_size - r, buf, r); } } } @@ -614,6 +868,23 @@ commandrv (char **stdoutput, char **stderror, char const* const *argv) } } + if (flag_copy_stdin) { + /* Check copy process didn't fail. */ + if (waitpid (stdin_pid, &r, 0) != stdin_pid) { + perror ("waitpid"); + kill (pid, 9); + waitpid (pid, NULL, 0); + return -1; + } + + if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) { + fprintf (stderr, "failed copying from input file, see earlier messages\n"); + kill (pid, 9); + waitpid (pid, NULL, 0); + return -1; + } + } + /* Get the exit status of the command. */ if (waitpid (pid, &r, 0) != pid) { perror ("waitpid"); @@ -651,7 +922,7 @@ split_lines (char *str) int size = 0, alloc = 0; char *p, *pend; - if (strcmp (str, "") == 0) + if (STREQ (str, "")) goto empty_list; p = str; @@ -680,6 +951,28 @@ split_lines (char *str) return lines; } +/* Skip leading and trailing whitespace, updating the original string + * in-place. + */ +void +trim (char *str) +{ + size_t len = strlen (str); + + while (len > 0 && c_isspace (str[len-1])) { + str[len-1] = '\0'; + len--; + } + + const char *p = str; + while (*p && c_isspace (*p)) { + p++; + len--; + } + + memmove (str, p, len+1); +} + /* printf helper function so we can use %Q ("quoted") and %R to print * shell-quoted strings. See HACKING file for more details. */ @@ -688,7 +981,7 @@ print_shell_quote (FILE *stream, const struct printf_info *info ATTRIBUTE_UNUSED, const void *const *args) { -#define SAFE(c) (isalnum((c)) || \ +#define SAFE(c) (c_isalnum((c)) || \ (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.') int i, len; const char *str = *((const char **) (args[0])); @@ -748,53 +1041,74 @@ print_arginfo (const struct printf_info *info, size_t n, int *argtypes) * the device nodes themselves will exist in the appliance. */ int -device_name_translation (char *device, const char *func) +device_name_translation (char *device) { int fd; fd = open (device, O_RDONLY); if (fd >= 0) { + close_ok: close (fd); return 0; } - if (errno != ENXIO && errno != ENOENT) { - error: - reply_with_perror ("%s: %s", func, device); + if (errno != ENXIO && errno != ENOENT) return -1; - } /* If the name begins with "/dev/sd" then try the alternatives. */ - if (strncmp (device, "/dev/sd", 7) != 0) - goto error; + if (STRNEQLEN (device, "/dev/sd", 7)) + return -1; device[5] = 'h'; /* /dev/hd (old IDE driver) */ fd = open (device, O_RDONLY); - if (fd >= 0) { - close (fd); - return 0; - } + if (fd >= 0) + goto close_ok; device[5] = 'v'; /* /dev/vd (for virtio devices) */ fd = open (device, O_RDONLY); - if (fd >= 0) { - close (fd); - return 0; - } + if (fd >= 0) + goto close_ok; device[5] = 's'; /* Restore original device name. */ - goto error; + return -1; +} + +/* Check program exists and is executable on $PATH. Actually, we + * just assume PATH contains the default entries (see main() above). + */ +int +prog_exists (const char *prog) +{ + static const char * const dirs[] = + { "/sbin", "/usr/sbin", "/bin", "/usr/bin" }; + size_t i; + char buf[1024]; + + for (i = 0; i < sizeof dirs / sizeof dirs[0]; ++i) { + snprintf (buf, sizeof buf, "%s/%s", dirs[i], prog); + if (access (buf, X_OK) == 0) + return 1; + } + return 0; } /* 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. + * + * 'udevsettle' was the old name for this command (RHEL 5). This was + * deprecated in favour of 'udevadm settle'. The old 'udevsettle' + * command was left as a symlink. Then in Fedora 13 the old symlink + * remained but it stopped working (RHBZ#548121), so we have to be + * careful not to assume that we can use 'udevsettle' if it exists. */ void udev_settle (void) { - command (NULL, NULL, "/sbin/udevadm", "settle", NULL); + (void) command (NULL, NULL, "udevadm", "settle", NULL); + (void) command (NULL, NULL, "udevsettle", NULL); }