[PATCH] use numeric owner/group as default values to avoid parsing userdb

[elogind.git] / udevsend.c

diff --git a/udevsend.c b/udevsend.c
index 7db2378b83b16afc9bda5e8a91cd56b52a721924..5fe0f456a1d7e4dc65e8c3e2c989fc5aebaf93ed 100644 (file)
--- a/udevsend.c
+++ b/udevsend.c
@@ -36,13 +36,14 @@
 #include <linux/stddef.h>
 
 #include "udev.h"
-#include "udev_lib.h"
 #include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"
 
+/* global variables */
+static int sock = -1;
+
 #ifdef LOG
-unsigned char logname[LOGNAME_SIZE];
 void log_message (int level, const char *format, ...)
 {
        va_list args;
@@ -57,6 +58,8 @@ static int start_daemon(void)
 {
        pid_t pid;
        pid_t child_pid;
+       char *const argv[] = { "udevd", NULL };
+       char *const envp[] = { NULL };
 
        pid = fork();
        switch (pid) {
@@ -65,10 +68,9 @@ static int start_daemon(void)
                child_pid = fork();
                switch (child_pid) {
                case 0:
-                       /* daemon */
-                       setsid();
-                       chdir("/");
-                       execl(UDEVD_BIN, "udevd", NULL);
+                       /* daemon with empty environment */
+                       close(sock);
+                       execve(UDEVD_BIN, argv, envp);
                        dbg("exec of daemon failed");
                        _exit(1);
                case -1:
@@ -89,13 +91,14 @@ static int start_daemon(void)
 
 static void run_udev(const char *subsystem)
 {
+       char *const argv[] = { "udev", (char *)subsystem, NULL };
        pid_t pid;
 
        pid = fork();
        switch (pid) {
        case 0:
                /* child */
-               execl(UDEV_BIN, "udev", subsystem, NULL);
+               execv(UDEV_BIN, argv);
                dbg("exec of child failed");
                _exit(1);
                break;
@@ -115,30 +118,20 @@ int main(int argc, char *argv[], char *envp[])
        int loop;
        struct sockaddr_un saddr;
        socklen_t addrlen;
-       const char *subsystem_argv;
-       int subsystem_env = 0;
        int bufpos = 0;
        int retval = 1;
-       int sock = -1;
        int started_daemon = 0;
+       const char *subsystem = NULL;
 
        logging_init("udevsend");
        dbg("version %s", UDEV_VERSION);
 
-       subsystem_argv = argv[1];
-       if (subsystem_argv == NULL) {
-               dbg("no subsystem");
-               goto exit;
-       }
-
        sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
        if (sock == -1) {
                dbg("error getting socket");
                goto fallback;
        }
 
-       set_cloexec_flag(sock, 1);
-
        memset(&saddr, 0x00, sizeof(struct sockaddr_un));
        saddr.sun_family = AF_LOCAL;
        /* use abstract namespace for socket path */
@@ -146,7 +139,6 @@ int main(int argc, char *argv[], char *envp[])
        addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 
        memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
-
        strcpy(usend_msg.magic, UDEV_MAGIC);
 
        /* copy all keys to send buffer */
@@ -156,22 +148,30 @@ int main(int argc, char *argv[], char *envp[])
 
                key = envp[i];
                keylen = strlen(key);
+
+               /* prevent loops in the scripts we execute */
+               if (strncmp(key, "UDEVD_EVENT=", 12) == 0) {
+                       dbg("seems that the event source is not the kernel, just exit");
+                       goto exit;
+               }
+
                if (bufpos + keylen >= HOTPLUG_BUFFER_SIZE-1) {
                        dbg("environment buffer too small, probably not called by the kernel");
                        continue;
                }
 
-               /* older kernels do not have the SUBSYSTEM in the environment */
+               /* remember the SUBSYSTEM */
                if (strncmp(key, "SUBSYSTEM=", 10) == 0)
-                       subsystem_env = 1;
+                       subsystem = &key[10];
 
                dbg("add '%s' to env[%i] buffer", key, i);
                strcpy(&usend_msg.envbuf[bufpos], key);
                bufpos += keylen + 1;
        }
-       if (!subsystem_env) {
-               bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", subsystem_argv) + 1;
-               dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", subsystem_argv, i);
+       /* older kernels passed the SUBSYSTEM only as the first argument */
+       if (!subsystem && argc == 2) {
+               bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", argv[1]) + 1;
+               dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", argv[1], i);
        }
 
        usend_msg_len = offsetof(struct udevsend_msg, envbuf) + bufpos;
@@ -195,10 +195,10 @@ int main(int argc, char *argv[], char *envp[])
                        dbg("try to start udevd daemon");
                        retval = start_daemon();
                        if (retval) {
-                               info("error starting daemon");
+                               dbg("error starting daemon");
                                goto fallback;
                        }
-                       info("udevd daemon started");
+                       dbg("udevd daemon started");
                        started_daemon = 1;
                } else {
                        dbg("retry to connect %d", SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND - loop);
@@ -208,7 +208,7 @@ int main(int argc, char *argv[], char *envp[])
 
 fallback:
        info("unable to connect to event daemon, try to call udev directly");
-       run_udev(subsystem_argv);
+       run_udev(subsystem);
 
 exit:
        if (sock != -1)