udev_utils_run.c revision 1aa1e24848903d11780db1ade355be73ad61a937
/*
* udev_utils_run.c - execute programs from udev and read its output
*
* Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
*
* 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 version 2 of the License.
*
* 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, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/select.h>
#include "udev.h"
int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
{
int sock;
struct sockaddr_un saddr;
socklen_t addrlen;
char buf[2048];
size_t bufpos = 0;
int i;
ssize_t count;
int retval = 0;
dbg("pass environment to socket '%s'", sockname);
sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
memset(&saddr, 0x00, sizeof(struct sockaddr_un));
saddr.sun_family = AF_LOCAL;
/* only abstract namespace is supported */
strcpy(&saddr.sun_path[1], sockname);
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
bufpos++;
for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
bufpos++;
}
count = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
if (count < 0)
retval = -1;
info("passed %zi bytes to socket '%s', ", count, sockname);
close(sock);
return retval;
}
int run_program(const char *command, const char *subsystem,
char *result, size_t ressize, size_t *reslen, int log)
{
int retval = 0;
int status;
int outpipe[2] = {-1, -1};
int errpipe[2] = {-1, -1};
pid_t pid;
char arg[PATH_SIZE];
char program[PATH_SIZE];
char *argv[(sizeof(arg) / 2) + 1];
int devnull;
int i;
strlcpy(arg, command, sizeof(arg));
i = 0;
if (strchr(arg, ' ')) {
char *pos = arg;
while (pos != NULL) {
if (pos[0] == '\'') {
/* don't separate if in apostrophes */
pos++;
argv[i] = strsep(&pos, "\'");
while (pos && pos[0] == ' ')
pos++;
} else {
argv[i] = strsep(&pos, " ");
}
dbg("arg[%i] '%s'", i, argv[i]);
i++;
}
argv[i] = NULL;
info("'%s'", command);
} else {
argv[0] = arg;
argv[1] = (char *) subsystem;
argv[2] = NULL;
info("'%s' '%s'", arg, argv[1]);
}
/* prepare pipes from child to parent */
if (result || log) {
if (pipe(outpipe) != 0) {
err("pipe failed: %s", strerror(errno));
return -1;
}
}
if (log) {
if (pipe(errpipe) != 0) {
err("pipe failed: %s", strerror(errno));
return -1;
}
}
/* allow programs in /lib/udev called without the path */
if (strchr(argv[0], '/') == NULL) {
strlcpy(program, "/lib/udev/", sizeof(program));
strlcat(program, argv[0], sizeof(program));
argv[0] = program;
}
pid = fork();
switch(pid) {
case 0:
/* child closes parent ends of pipes */
if (outpipe[READ_END] > 0)
close(outpipe[READ_END]);
if (errpipe[READ_END] > 0)
close(errpipe[READ_END]);
/* discard child output or connect to pipe */
devnull = open("/dev/null", O_RDWR);
if (devnull > 0) {
dup2(devnull, STDIN_FILENO);
if (outpipe[WRITE_END] < 0)
dup2(devnull, STDOUT_FILENO);
if (errpipe[WRITE_END] < 0)
dup2(devnull, STDERR_FILENO);
close(devnull);
} else
err("open /dev/null failed: %s", strerror(errno));
if (outpipe[WRITE_END] > 0)
dup2(outpipe[WRITE_END], STDOUT_FILENO);
if (errpipe[WRITE_END] > 0)
dup2(errpipe[WRITE_END], STDERR_FILENO);
execv(argv[0], argv);
/* we should never reach this */
err("exec of program '%s' failed", argv[0]);
_exit(1);
case -1:
err("fork of '%s' failed: %s", argv[0], strerror(errno));
return -1;
default:
/* read from child if requested */
if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
ssize_t count;
size_t respos = 0;
/* parent closes child ends of pipes */
if (outpipe[WRITE_END] > 0)
close(outpipe[WRITE_END]);
if (errpipe[WRITE_END] > 0)
close(errpipe[WRITE_END]);
/* read child output */
while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
int fdcount;
fd_set readfds;
FD_ZERO(&readfds);
if (outpipe[READ_END] > 0)
FD_SET(outpipe[READ_END], &readfds);
if (errpipe[READ_END] > 0)
FD_SET(errpipe[READ_END], &readfds);
fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
if (fdcount < 0) {
if (errno == EINTR)
continue;
retval = -1;
break;
}
/* get stdout */
if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
char inbuf[1024];
char *pos;
char *line;
count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
if (count <= 0) {
close(outpipe[READ_END]);
outpipe[READ_END] = -1;
if (count < 0) {
err("stdin read failed: %s", strerror(errno));
retval = -1;
}
continue;
}
inbuf[count] = '\0';
/* store result for rule processing */
if (result) {
if (respos + count < ressize) {
memcpy(&result[respos], inbuf, count);
respos += count;
} else {
err("ressize %ld too short", (long)ressize);
retval = -1;
}
}
pos = inbuf;
while ((line = strsep(&pos, "\n")))
if (pos || line[0] != '\0')
info("'%s' (stdout) '%s'", argv[0], line);
}
/* get stderr */
if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
char errbuf[1024];
char *pos;
char *line;
count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
if (count <= 0) {
close(errpipe[READ_END]);
errpipe[READ_END] = -1;
if (count < 0)
err("stderr read failed: %s", strerror(errno));
continue;
}
errbuf[count] = '\0';
pos = errbuf;
while ((line = strsep(&pos, "\n")))
if (pos || line[0] != '\0')
info("'%s' (stderr) '%s'", argv[0], line);
}
}
if (outpipe[READ_END] > 0)
close(outpipe[READ_END]);
if (errpipe[READ_END] > 0)
close(errpipe[READ_END]);
/* return the childs stdout string */
if (result) {
result[respos] = '\0';
dbg("result='%s'", result);
if (reslen)
*reslen = respos;
}
}
waitpid(pid, &status, 0);
if (WIFEXITED(status)) {
info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
if (WEXITSTATUS(status) != 0)
retval = -1;
} else {
err("'%s' abnormal exit", argv[0]);
retval = -1;
}
}
return retval;
}