/* 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
#include <config.h>
+#define _BSD_SOURCE /* for daemon(3) */
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <rpc/xdr.h>
#include <getopt.h>
#include <netdb.h>
+#include <sys/param.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <printf.h>
+
+#include "c-ctype.h"
+#include "ignore-value.h"
-static void xwrite (int sock, const void *buf, size_t len);
-static void usage (void);
+#include "daemon.h"
+
+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;
- unsigned len;
+ 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 '?':
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';
+ cmdline = read_cmdline ();
- p = strstr (buf, "guestfs=");
+ /* Set the verbose flag. */
+ verbose = verbose ||
+ (cmdline && strstr (cmdline, "guestfs_verbose=1") != NULL);
+ if (verbose)
+ printf ("verbose daemon enabled\n");
+ 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 ... */
+
+ /* 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) {
- p += 8;
- p2 = strchr (p, ':');
- if (p2) {
- *p2++ = '\0';
- host = p;
- r = strcspn (p2, " \n");
- p2[r] = '\0';
- port = p2;
+ len = strcspn (p + 18, " \t\n");
+ vmchannel = strndup (p + 18, len);
+ if (!vmchannel) {
+ perror ("strndup");
+ exit (1);
}
}
- }
- next:
- /* Can't parse /proc/cmdline, so use built-in defaults. */
- if (!host || !port) {
- host = VMCHANNEL_ADDR;
- port = VMCHANNEL_PORT;
+ /* 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);
+ }
+ }
}
- /* 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);
+ /* Default vmchannel. */
+ if (vmchannel == NULL) {
+ vmchannel = strdup ("tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT);
+ if (!vmchannel) {
+ perror ("strdup");
+ 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");
+ if (verbose)
+ printf ("vmchannel: %s\n", vmchannel);
+
+ /* Connect to vmchannel. */
+ int 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:<ip>:<port>\": %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;
+ close (sock);
+ sock = -1;
+ }
}
+ freeaddrinfo (res);
+ } else {
+ fprintf (stderr,
+ "unknown vmchannel connection type: %s\n"
+ "expecting \"tcp:<ip>:<port>\"\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 = 0xf5f55ff5;
- 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);
- xwrite (sock, buf, xdr_getpos (&xdr));
+ if (xwrite (sock, lenbuf, sizeof lenbuf) == -1)
+ exit (1);
xdr_destroy (&xdr);
- /* XXX Fork into the background. */
+ /* Fork into the background. */
+ if (!dont_fork) {
+ if (daemon (0, 1) == -1) {
+ perror ("daemon");
+ exit (1);
+ }
+ }
+ /* Enter the main loop, reading and performing actions. */
+ main_loop (sock);
+ 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;
- sleep (1000000);
+ r = malloc (len);
+ if (r == NULL)
+ return NULL;
- exit (0);
+ snprintf (r, len, "%s%s", sysroot, path);
+ return r;
}
-static void
-xwrite (int sock, const void *buf, size_t len)
+int
+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);
if (r == -1) {
perror ("write");
- exit (1);
+ return -1;
}
buf += r;
len -= r;
}
+
+ return 0;
}
-static void
-usage (void)
+int
+xread (int sock, void *v_buf, size_t len)
+{
+ int r;
+ char *buf = v_buf;
+
+ while (len > 0) {
+ r = read (sock, buf, len);
+ if (r == -1) {
+ perror ("read");
+ return -1;
+ }
+ if (r == 0) {
+ fprintf (stderr, "read: unexpected end of file on fd %d\n", sock);
+ return -1;
+ }
+ buf += r;
+ len -= r;
+ }
+
+ return 0;
+}
+
+int
+add_string (char ***argv, int *size, int *alloc, const char *str)
+{
+ char **new_argv;
+ char *new_str;
+
+ if (*size >= *alloc) {
+ *alloc += 64;
+ new_argv = realloc (*argv, *alloc * sizeof (char *));
+ if (new_argv == NULL) {
+ reply_with_perror ("realloc");
+ free_strings (*argv);
+ return -1;
+ }
+ *argv = new_argv;
+ }
+
+ if (str) {
+ new_str = strdup (str);
+ if (new_str == NULL) {
+ reply_with_perror ("strdup");
+ free_strings (*argv);
+ }
+ } else
+ new_str = NULL;
+
+ (*argv)[*size] = new_str;
+
+ (*size)++;
+ return 0;
+}
+
+int
+count_strings (char *const *argv)
+{
+ int argc;
+
+ for (argc = 0; argv[argc] != NULL; ++argc)
+ ;
+ return argc;
+}
+
+static int
+compare (const void *vp1, const void *vp2)
+{
+ char * const *p1 = (char * const *) vp1;
+ char * const *p2 = (char * const *) vp2;
+ return strcmp (*p1, *p2);
+}
+
+void
+sort_strings (char **argv, int len)
+{
+ qsort (argv, len, sizeof (char *), compare);
+}
+
+void
+free_strings (char **argv)
+{
+ int argc;
+
+ for (argc = 0; argv[argc] != NULL; ++argc)
+ free (argv[argc]);
+ free (argv);
+}
+
+void
+free_stringslen (char **argv, int len)
+{
+ int i;
+
+ for (i = 0; i < len; ++i)
+ free (argv[i]);
+ free (argv);
+}
+
+/* Easy ways to run external commands. For full documentation, see
+ * 'commandrvf' below.
+ */
+int
+commandf (char **stdoutput, char **stderror, int flags, const char *name, ...)
+{
+ va_list args;
+ const char **argv;
+ char *s;
+ int i, r;
+
+ /* Collect the command line arguments into an array. */
+ i = 2;
+ argv = malloc (sizeof (char *) * i);
+ if (argv == NULL) {
+ perror ("malloc");
+ return -1;
+ }
+ argv[0] = (char *) name;
+ argv[1] = NULL;
+
+ va_start (args, name);
+
+ while ((s = va_arg (args, char *)) != NULL) {
+ const char **p = realloc (argv, sizeof (char *) * (++i));
+ if (p == NULL) {
+ perror ("realloc");
+ free (argv);
+ va_end (args);
+ return -1;
+ }
+ argv = p;
+ argv[i-2] = s;
+ argv[i-1] = NULL;
+ }
+
+ va_end (args);
+
+ r = commandvf (stdoutput, stderror, flags, (const char * const*) argv);
+
+ /* NB: Mustn't free the strings which are on the stack. */
+ free (argv);
+
+ return r;
+}
+
+/* Same as 'command', but we allow the status code from the
+ * subcommand to be non-zero, and return that status code.
+ * We still return -1 if there was some other error.
+ */
+int
+commandrf (char **stdoutput, char **stderror, int flags, const char *name, ...)
+{
+ va_list args;
+ const char **argv;
+ char *s;
+ int i, r;
+
+ /* Collect the command line arguments into an array. */
+ i = 2;
+ argv = malloc (sizeof (char *) * i);
+ if (argv == NULL) {
+ perror ("malloc");
+ return -1;
+ }
+ argv[0] = (char *) name;
+ argv[1] = NULL;
+
+ va_start (args, name);
+
+ while ((s = va_arg (args, char *)) != NULL) {
+ const char **p = realloc (argv, sizeof (char *) * (++i));
+ if (p == NULL) {
+ perror ("realloc");
+ free (argv);
+ va_end (args);
+ return -1;
+ }
+ argv = p;
+ argv[i-2] = s;
+ argv[i-1] = NULL;
+ }
+
+ va_end (args);
+
+ r = commandrvf (stdoutput, stderror, flags, argv);
+
+ /* NB: Mustn't free the strings which are on the stack. */
+ free (argv);
+
+ return r;
+}
+
+/* Same as 'command', but passing an argv. */
+int
+commandvf (char **stdoutput, char **stderror, int flags,
+ char const *const *argv)
+{
+ int r;
+
+ 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.
+ */
+int
+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 r, quit, i;
+ fd_set rset, rset2;
+ char buf[256];
+ char *p;
+
+ if (stdoutput) *stdoutput = NULL;
+ if (stderror) *stderror = NULL;
+
+ if (verbose) {
+ printf ("%s", argv[0]);
+ for (i = 1; argv[i] != NULL; ++i)
+ printf (" %s", argv[i]);
+ printf ("\n");
+ }
+
+ if (pipe (so_fd) == -1 || pipe (se_fd) == -1) {
+ perror ("pipe");
+ return -1;
+ }
+
+ 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;
+ }
+
+ if (pid == 0) { /* Child process. */
+ close (0);
+ open ("/dev/null", O_RDONLY); /* Set stdin to /dev/null (ignore failure) */
+ close (so_fd[0]);
+ close (se_fd[0]);
+ 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);
+ }
+
+ /* Parent process. */
+ close (so_fd[1]);
+ close (se_fd[1]);
+
+ FD_ZERO (&rset);
+ FD_SET (so_fd[0], &rset);
+ FD_SET (se_fd[0], &rset);
+
+ quit = 0;
+ while (quit < 2) {
+ rset2 = rset;
+ r = select (MAX (so_fd[0], se_fd[0]) + 1, &rset2, NULL, NULL, NULL);
+ if (r == -1) {
+ perror ("select");
+ quit:
+ if (stdoutput) free (*stdoutput);
+ if (stderror) free (*stderror);
+ close (so_fd[0]);
+ close (se_fd[0]);
+ waitpid (pid, NULL, 0);
+ return -1;
+ }
+
+ 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;
+ }
+ 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);
+ }
+ }
+
+ 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;
+ }
+ if (r == 0) { FD_CLR (se_fd[0], &rset); 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);
+ }
+ }
+ }
+ }
+
+ close (so_fd[0]);
+ close (se_fd[0]);
+
+ /* Make sure the output buffers are \0-terminated. Also remove any
+ * trailing \n characters from the error buffer (not from stdout).
+ */
+ if (stdoutput) {
+ void *q = realloc (*stdoutput, so_size+1);
+ if (q == NULL) {
+ perror ("realloc");
+ free (*stdoutput);
+ }
+ *stdoutput = q;
+ if (*stdoutput)
+ (*stdoutput)[so_size] = '\0';
+ }
+ if (stderror) {
+ void *q = realloc (*stderror, se_size+1);
+ if (q == NULL) {
+ perror ("realloc");
+ free (*stderror);
+ }
+ *stderror = q;
+ if (*stderror) {
+ (*stderror)[se_size] = '\0';
+ se_size--;
+ while (se_size >= 0 && (*stderror)[se_size] == '\n')
+ (*stderror)[se_size--] = '\0';
+ }
+ }
+
+ /* Get the exit status of the command. */
+ if (waitpid (pid, &r, 0) != pid) {
+ perror ("waitpid");
+ return -1;
+ }
+
+ if (WIFEXITED (r)) {
+ return WEXITSTATUS (r);
+ } else
+ return -1;
+}
+
+/* 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.
+ *
+ * The corner cases here are quite tricky. Note in particular:
+ *
+ * "" -> []
+ * "\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.
+ */
+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) (c_isalnum((c)) || \
+ (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 ++;
+ }
+
+ return len;
+}
+
+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);
+}
+
+#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
+
+/* 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;
+ }
+
+ 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 (STRNEQLEN (device, "/dev/sd", 7))
+ goto error;
+
+ device[5] = 'h'; /* /dev/hd (old IDE driver) */
+ fd = open (device, O_RDONLY);
+ if (fd >= 0) {
+ close (fd);
+ return 0;
+ }
+
+ 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)
{
- fprintf (stderr, "guestfsd [-f] [-h host -p port]\n");
+ command (NULL, NULL, "/sbin/udevadm", "settle", NULL);
}
git.annexia.org / libguestfs.git / blobdiff