X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fguestfsd.c;h=2e83b9fa96db06590b8f1f788343fb295a06273a;hp=6fc8b19fbd25f629063e9fc89dc44a4a5ac9dc27;hb=875dc84cc01dacb1e254e294a66e179b96fbdbc6;hpb=d134143b55ecb5f7e6f74318acbf04f9e1370af6 diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index 6fc8b19..2e83b9f 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -18,6 +18,8 @@ #include +#define _BSD_SOURCE /* for daemon(3) */ + #include #include #include @@ -26,17 +28,25 @@ #include #include #include +#include +#include +#include +#include +#include +#include +#include +#include #include "daemon.h" -void xwrite (int sock, const void *buf, size_t len); - static void usage (void); /* Also in guestfs.c */ #define VMCHANNEL_PORT "6666" #define VMCHANNEL_ADDR "10.0.2.4" +int verbose = 0; + int main (int argc, char *argv[]) { @@ -59,7 +69,8 @@ main (int argc, char *argv[]) struct addrinfo *res, *rr; struct addrinfo hints; XDR xdr; - unsigned len; + uint32_t len; + struct sigaction sa; for (;;) { c = getopt_long (argc, argv, options, long_options, NULL); @@ -104,6 +115,14 @@ main (int argc, char *argv[]) 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"); + p = strstr (buf, "guestfs="); if (p) { @@ -126,6 +145,21 @@ main (int argc, char *argv[]) port = VMCHANNEL_PORT; } + /* Make sure SIGPIPE doesn't kill us. */ + 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 ("LANG", "C", 1); + /* Resolve the hostname. */ memset (&hints, 0, sizeof hints); hints.ai_socktype = SOCK_STREAM; @@ -159,36 +193,32 @@ main (int argc, char *argv[]) /* Send the magic length message which indicates that * userspace is up inside the guest. */ - len = 0xf5f55ff5; + 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); } - xwrite (sock, buf, xdr_getpos (&xdr)); + (void) xwrite (sock, buf, xdr_getpos (&xdr)); 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); } -void +int xwrite (int sock, const void *buf, size_t len) { int r; @@ -197,14 +227,16 @@ xwrite (int sock, const void *buf, size_t len) r = write (sock, buf, len); if (r == -1) { perror ("write"); - exit (1); + return -1; } buf += r; len -= r; } + + return 0; } -void +int xread (int sock, void *buf, size_t len) { int r; @@ -213,15 +245,17 @@ xread (int sock, void *buf, size_t len) r = read (sock, buf, len); if (r == -1) { perror ("read"); - exit (1); + return -1; } if (r == 0) { - fprintf (stderr, "read: unexpected end of file on comms socket\n"); - exit (1); + fprintf (stderr, "read: unexpected end of file on fd %d\n", sock); + return -1; } buf += r; len -= r; } + + return 0; } static void @@ -230,17 +264,473 @@ usage (void) fprintf (stderr, "guestfsd [-f] [-h host -p port]\n"); } -/* Some unimplemented actions. */ int -do_mount (const char *device, const char *mountpoint) +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* 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); +} + +/* 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. + */ +int +command (char **stdoutput, char **stderror, const char *name, ...) +{ + va_list args; + char **argv, **p; + 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) { + 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 = commandv (stdoutput, stderror, 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 +commandr (char **stdoutput, char **stderror, const char *name, ...) { - reply_with_error ("mount not implemented"); - return -1; + va_list args; + char **argv, **p; + 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) { + 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 = commandrv (stdoutput, stderror, argv); + + /* NB: Mustn't free the strings which are on the stack. */ + free (argv); + + return r; } +/* Same as 'command', but passing an argv. */ int -do_touch (const char *path) +commandv (char **stdoutput, char **stderror, char * const* const argv) { - reply_with_error ("touch not implemented"); - return -1; + int r; + + r = commandrv (stdoutput, stderror, argv); + if (r == 0) + return 0; + else + return -1; +} + +int +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; + 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); + close (so_fd[0]); + close (se_fd[0]); + dup2 (so_fd[1], 1); + dup2 (se_fd[1], 2); + close (so_fd[1]); + close (se_fd[1]); + + execvp (argv[0], 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 && 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) { + *stdoutput = realloc (*stdoutput, so_size+1); + if (*stdoutput == NULL) { + perror ("realloc"); + *stdoutput = NULL; + } else + (*stdoutput)[so_size] = '\0'; + } + if (stderror) { + *stderror = realloc (*stderror, se_size+1); + if (*stderror == NULL) { + perror ("realloc"); + *stderror = NULL; + } else { + (*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. */ + waitpid (pid, &r, 0); + + 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; +} + +/* Quote 'in' for the shell, and write max len-1 bytes to out. The + * result will be NUL-terminated, even if it is truncated. + * + * Returns number of bytes needed, so if result >= len then the buffer + * should have been longer. + * + * XXX This doesn't quote \n correctly (but is still safe). + */ +int +shell_quote (char *out, int len, const char *in) +{ +#define SAFE(c) (isalnum((c)) || \ + (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.') + int i, j; + int outlen = strlen (in); + + /* Calculate how much output space this really needs. */ + for (i = 0; in[i]; ++i) + if (!SAFE (in[i])) outlen++; + + /* 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]); + + /* Enough space left to write this character? */ + if (j >= len-1 || (!is_safe && j >= len-2)) + break; + + if (!is_safe) out[j++] = '\\'; + out[j++] = in[i]; + } + + out[j] = '\0'; + + return outlen; +} + +/* Perform device name translation. Don't call this directly - + * use the IS_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) { + 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; + } + + 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; }