qubes-installer-qubes-os/isys/imount.c
2011-01-18 04:24:57 -05:00

291 lines
7.4 KiB
C

/*
* imount.c
*
* Copyright (C) 2007, 2008, 2009 Red Hat, Inc. All rights reserved.
*
* 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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "imount.h"
#define _(foo) foo
static int mkdirIfNone(char * directory);
static int readFD(int fd, char **buf) {
char *p;
size_t size = 4096;
int s, filesize = 0;
*buf = calloc(4096, sizeof (char));
if (*buf == NULL)
abort();
do {
p = &(*buf)[filesize];
s = read(fd, p, 4096);
if (s < 0)
break;
filesize += s;
if (s == 0)
break;
size += s;
*buf = realloc(*buf, size);
if (*buf == NULL)
abort();
} while (1);
if (filesize == 0 && s < 0) {
free(*buf);
*buf = NULL;
return -1;
}
return filesize;
}
int mountCommandWrapper(int mode, char *dev, char *where, char *fs,
char *options, char **err) {
int rc, child, status, pipefd[2];
char *opts = NULL, *device = NULL, *cmd = NULL;
int programLogFD;
if (mode == IMOUNT_MODE_MOUNT) {
cmd = "/bin/mount";
} else if (mode == IMOUNT_MODE_UMOUNT) {
cmd = "/bin/umount";
} else {
return IMOUNT_ERR_MODE;
}
if (mode == IMOUNT_MODE_MOUNT) {
if (mkdirChain(where))
return IMOUNT_ERR_ERRNO;
if (strstr(fs, "nfs")) {
if (options) {
if (asprintf(&opts, "%s,nolock", options) == -1) {
fprintf(stderr, "%s: %d: %s\n", __func__, __LINE__,
strerror(errno));
fflush(stderr);
abort();
}
} else {
opts = strdup("nolock");
}
device = strdup(dev);
} else {
if ((options && strstr(options, "bind") == NULL) &&
strncmp(dev, "LABEL=", 6) && strncmp(dev, "UUID=", 5) &&
*dev != '/') {
if (asprintf(&device, "/dev/%s", dev) == -1) {
fprintf(stderr, "%s: %d: %s\n", __func__, __LINE__,
strerror(errno));
fflush(stderr);
abort();
}
} else {
device = strdup(dev);
}
if (options)
opts = strdup(options);
}
}
programLogFD = open("/tmp/program.log",
O_APPEND|O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
if (pipe(pipefd))
return IMOUNT_ERR_ERRNO;
if (!(child = fork())) {
int fd;
close(pipefd[0]);
/* Close stdin entirely, redirect stdout to /tmp/program.log, and
* redirect stderr to a pipe so we can put error messages into
* exceptions. We'll only use these messages should mount also
* return an error code.
*/
fd = open("/dev/tty5", O_RDONLY);
close(STDIN_FILENO);
dup2(fd, STDIN_FILENO);
close(fd);
close(STDOUT_FILENO);
dup2(programLogFD, STDOUT_FILENO);
dup2(pipefd[1], STDERR_FILENO);
if (mode == IMOUNT_MODE_MOUNT) {
if (opts) {
fprintf(stdout, "Running... %s -n -t %s -o %s %s %s\n",
cmd, fs, opts, device, where);
rc = execl(cmd, cmd,
"-n", "-t", fs, "-o", opts, device, where, NULL);
exit(1);
} else {
fprintf(stdout, "Running... %s -n -t %s %s %s\n",
cmd, fs, device, where);
rc = execl(cmd, cmd, "-n", "-t", fs, device, where, NULL);
exit(1);
}
} else if (mode == IMOUNT_MODE_UMOUNT) {
fprintf(stdout, "Running... %s %s\n", cmd, where);
rc = execl(cmd, cmd, where, NULL);
exit(1);
} else {
fprintf(stdout, "Running... Unknown imount mode: %d\n", mode);
exit(1);
}
}
close(pipefd[1]);
if (err != NULL) {
if (*err != NULL) {
rc = readFD(pipefd[0], err);
rc = write(programLogFD, *err, 4096);
}
}
close(pipefd[0]);
waitpid(child, &status, 0);
close(programLogFD);
if (opts) {
free(opts);
}
if (device) {
free(device);
}
if (!WIFEXITED(status))
return IMOUNT_ERR_OTHER;
else if ( (rc = WEXITSTATUS(status)) ) {
/* Refer to 'man mount' for the meaning of the error codes. */
switch (rc) {
case 1:
return IMOUNT_ERR_PERMISSIONS;
case 2:
return IMOUNT_ERR_SYSTEM;
case 4:
return IMOUNT_ERR_MOUNTINTERNAL;
case 8:
return IMOUNT_ERR_USERINTERRUPT;
case 16:
return IMOUNT_ERR_MTAB;
case 32:
return IMOUNT_ERR_MOUNTFAILURE;
case 64:
return IMOUNT_ERR_PARTIALSUCC;
default:
return IMOUNT_ERR_OTHER;
}
}
return 0;
}
int doPwMount(char *dev, char *where, char *fs, char *options, char **err) {
return mountCommandWrapper(IMOUNT_MODE_MOUNT,
dev, where, fs, options, err);
}
int doPwUmount(char *where, char **err) {
return mountCommandWrapper(IMOUNT_MODE_UMOUNT,
NULL, where, NULL, NULL, err);
}
int mkdirChain(char * origChain) {
char * chain;
char * chptr;
chain = alloca(strlen(origChain) + 1);
strcpy(chain, origChain);
chptr = chain;
while ((chptr = strchr(chptr, '/'))) {
*chptr = '\0';
if (mkdirIfNone(chain)) {
*chptr = '/';
return IMOUNT_ERR_ERRNO;
}
*chptr = '/';
chptr++;
}
if (mkdirIfNone(chain))
return IMOUNT_ERR_ERRNO;
return 0;
}
/* Returns true iff it is possible that the mount command that have returned
* 'errno' might succeed at a later time (think e.g. not yet initialized USB
* device, etc.) */
int mountMightSucceedLater(int mountRc)
{
int rc;
switch (mountRc) {
case IMOUNT_ERR_MOUNTFAILURE:
rc = 1;
break;
default:
rc = 0;
}
return rc;
}
static int mkdirIfNone(char * directory) {
int rc, mkerr;
char * chptr;
/* If the file exists it *better* be a directory -- I'm not going to
actually check or anything */
if (!access(directory, X_OK)) return 0;
/* if the path is '/' we get ENOFILE not found" from mkdir, rather
then EEXIST which is weird */
for (chptr = directory; *chptr; chptr++)
if (*chptr != '/') break;
if (!*chptr) return 0;
rc = mkdir(directory, 0755);
mkerr = errno;
if (!rc || mkerr == EEXIST) return 0;
return IMOUNT_ERR_ERRNO;
}