#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
+#include <sys/select.h>
#include "udev_libc_wrapper.h"
#include "udev.h"
return retval;
}
-int execute_program(const char *command, const char *subsystem,
- char *result, size_t ressize, size_t *reslen)
+int run_program(const char *command, const char *subsystem,
+ char *result, size_t ressize, size_t *reslen, int dbg)
{
int retval = 0;
- int count;
int status;
- int pipefds[2];
+ int outpipe[2] = {-1, -1};
+ int errpipe[2] = {-1, -1};
pid_t pid;
char *pos;
char arg[PATH_SIZE];
char *argv[(sizeof(arg) / 2) + 1];
int devnull;
int i;
- size_t len;
strlcpy(arg, command, sizeof(arg));
i = 0;
dbg("arg[%i] '%s'", i, argv[i]);
i++;
}
- argv[i] = NULL;
+ argv[i] = NULL;
dbg("execute '%s' with parsed arguments", arg);
} else {
argv[0] = arg;
dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
}
- if (result) {
- if (pipe(pipefds) != 0) {
+ /* prepare pipes from child to parent */
+ if (result || dbg) {
+ if (pipe(outpipe) != 0) {
+ err("pipe failed");
+ return -1;
+ }
+ }
+ if (dbg) {
+ if (pipe(errpipe) != 0) {
err("pipe failed");
return -1;
}
pid = fork();
switch(pid) {
case 0:
- /* child dup2 write side of pipe to STDOUT */
+ /* child closes parent ends of pipes */
+ if (outpipe[0] > 0)
+ close(outpipe[0]);
+ if (errpipe[0] > 0)
+ close(errpipe[0]);
+
+ /* discard child output or connect to pipe */
devnull = open("/dev/null", O_RDWR);
- if (devnull >= 0) {
- dup2(devnull, STDIN_FILENO);
- if (!result)
- dup2(devnull, STDOUT_FILENO);
- dup2(devnull, STDERR_FILENO);
- close(devnull);
+ if (devnull < 0) {
+ err("open /dev/null failed");
+ exit(1);
}
- if (result)
- dup2(pipefds[1], STDOUT_FILENO);
+ dup2(devnull, STDIN_FILENO);
+
+ if (outpipe[1] > 0)
+ dup2(outpipe[1], STDOUT_FILENO);
+ else
+ dup2(devnull, STDOUT_FILENO);
+
+ if (errpipe[1] > 0)
+ dup2(errpipe[1], STDERR_FILENO);
+ else
+ dup2(devnull, STDERR_FILENO);
+
+ close(devnull);
execv(arg, argv);
+
+ /* we should never reach this */
err("exec of program failed");
_exit(1);
case -1:
err("fork of '%s' failed", arg);
return -1;
default:
- /* parent reads from pipefds[0] */
- if (result) {
- close(pipefds[1]);
- len = 0;
- while (1) {
- count = read(pipefds[0], result + len, ressize - len-1);
- if (count < 0) {
- err("read failed with '%s'", strerror(errno));
+ /* read from child if requested */
+ if (outpipe[0] > 0 || errpipe[0] > 0) {
+ size_t count;
+ size_t respos = 0;
+
+ /* parent closes child ends of pipes */
+ if (outpipe[1] > 0)
+ close(outpipe[1]);
+ if (errpipe[1] > 0)
+ close(errpipe[1]);
+
+ /* read child output */
+ while (outpipe[0] > 0 || errpipe[0] > 0) {
+ int fdcount;
+ fd_set readfds;
+
+ FD_ZERO(&readfds);
+ if (outpipe[0] > 0)
+ FD_SET(outpipe[0], &readfds);
+ if (errpipe[0] > 0)
+ FD_SET(errpipe[0], &readfds);
+ fdcount = select(UDEV_MAX(outpipe[0], errpipe[0])+1, &readfds, NULL, NULL, NULL);
+ if (fdcount < 0) {
+ if (errno == EINTR)
+ continue;
retval = -1;
break;
}
- if (count == 0)
- break;
+ /* get stdout */
+ if (outpipe[0] > 0 && FD_ISSET(outpipe[0], &readfds)) {
+ char inbuf[1024];
- len += count;
- if (len >= ressize-1) {
- err("ressize %ld too short", (long)ressize);
- retval = -1;
- break;
+ count = read(outpipe[0], inbuf, sizeof(inbuf)-1);
+ if (count <= 0) {
+ close(outpipe[0]);
+ outpipe[0] = -1;
+ if (count < 0) {
+ err("stdin read failed with '%s'", strerror(errno));
+ retval = -1;
+ }
+ continue;
+ }
+ inbuf[count] = '\0';
+ dbg("stdout: '%s'", inbuf);
+
+ if (result) {
+ if (respos + count >= ressize) {
+ err("ressize %ld too short", (long)ressize);
+ retval = -1;
+ continue;
+ }
+ memcpy(&result[respos], inbuf, count);
+ respos += count;
+ }
+ }
+
+ /* get stderr */
+ if (errpipe[0] > 0 && FD_ISSET(errpipe[0], &readfds)) {
+ char errbuf[1024];
+
+ count = read(errpipe[0], errbuf, sizeof(errbuf)-1);
+ if (count <= 0) {
+ close(errpipe[0]);
+ errpipe[0] = -1;
+ if (count < 0)
+ err("stderr read failed with '%s'", strerror(errno));
+ continue;
+ }
+ errbuf[count] = '\0';
+ dbg("stderr: '%s'", errbuf);
}
}
- result[len] = '\0';
- close(pipefds[0]);
- if (reslen)
- *reslen = len;
+ if (outpipe[0] > 0)
+ close(outpipe[0]);
+ if (errpipe[0] > 0)
+ close(errpipe[0]);
+
+ /* 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) || (WEXITSTATUS(status) != 0)) {
dbg("exec program status 0x%x", status);
retval = -1;
return retval;
}
-
~ianmdlvl / elogind.git / blobdiff