diff options
Diffstat (limited to 'udev_utils_run.c')
| -rw-r--r-- | udev_utils_run.c | 156 |
1 files changed, 118 insertions, 38 deletions
diff --git a/udev_utils_run.c b/udev_utils_run.c index c2e77cbbcc..50b31781e7 100644 --- a/udev_utils_run.c +++ b/udev_utils_run.c @@ -29,6 +29,7 @@ #include <sys/socket.h> #include <sys/un.h> #include <sys/wait.h> +#include <sys/select.h> #include "udev_libc_wrapper.h" #include "udev.h" @@ -70,20 +71,19 @@ int pass_env_to_socket(const char *sockname, const char *devpath, const char *ac 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; @@ -102,7 +102,7 @@ int execute_program(const char *command, const char *subsystem, 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; @@ -111,8 +111,15 @@ int execute_program(const char *command, const char *subsystem, 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; } @@ -121,53 +128,127 @@ int execute_program(const char *command, const char *subsystem, 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; @@ -176,4 +257,3 @@ int execute_program(const char *command, const char *subsystem, return retval; } - |