chiark / gitweb /
[PATCH] use numeric owner/group as default values to avoid parsing userdb
[elogind.git] / udevsend.c
index 23ba1a1..5fe0f45 100644 (file)
 #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) {
@@ -65,12 +68,11 @@ 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);
+                       _exit(1);
                case -1:
                        dbg("fork of daemon failed");
                        return -1;
@@ -82,128 +84,125 @@ static int start_daemon(void)
                dbg("fork of helper failed");
                return -1;
        default:
-               wait(NULL);
+               waitpid(pid, NULL, 0);
        }
        return 0;
 }
 
 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);
+               _exit(1);
                break;
        case -1:
                dbg("fork of child failed");
                break;
        default:
-               wait(NULL);
+               waitpid(pid, NULL, 0);
        }
 }
 
-int main(int argc, char* argv[])
+int main(int argc, char *argv[], char *envp[])
 {
-       struct hotplug_msg msg;
-       char *action;
-       char *devpath;
-       char *subsystem;
-       char *seqnum;
-       unsigned long long seq;
-       int retval = 1;
+       static struct udevsend_msg usend_msg;
+       int usend_msg_len;
+       int i;
        int loop;
-       struct timespec tspec;
-       int sock = -1;
        struct sockaddr_un saddr;
        socklen_t addrlen;
+       int bufpos = 0;
+       int retval = 1;
        int started_daemon = 0;
+       const char *subsystem = NULL;
 
-       init_logging("udevsend");
+       logging_init("udevsend");
        dbg("version %s", UDEV_VERSION);
 
-       subsystem = get_subsystem(argv[1]);
-       if (subsystem == NULL) {
-               dbg("no subsystem");
-               goto exit;
-       }
-       dbg("subsystem = '%s'", subsystem);
-
-       devpath = get_devpath();
-       if (devpath == NULL) {
-               dbg("no devpath");
-               goto exit;
-       }
-       dbg("DEVPATH = '%s'", devpath);
-
-       action = get_action();
-       if (action == NULL) {
-               dbg("no action");
-               goto exit;
-       }
-       dbg("ACTION = '%s'", action);
-
-       seqnum = get_seqnum();
-       if (seqnum == NULL)
-               seq = 0;
-       else
-               seq = strtoull(seqnum, NULL, 10);
-       dbg("SEQNUM = '%llu'", seq);
-
        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 */
        strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
        addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 
-       memset(&msg, 0x00, sizeof(struct hotplug_msg));
-       strcpy(msg.magic, UDEV_MAGIC);
-       msg.seqnum = seq;
-       strfieldcpy(msg.action, action);
-       strfieldcpy(msg.devpath, devpath);
-       strfieldcpy(msg.subsystem, subsystem);
+       memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
+       strcpy(usend_msg.magic, UDEV_MAGIC);
+
+       /* copy all keys to send buffer */
+       for (i = 0; envp[i]; i++) {
+               const char *key;
+               int keylen;
+
+               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;
+               }
+
+               /* remember the SUBSYSTEM */
+               if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+                       subsystem = &key[10];
+
+               dbg("add '%s' to env[%i] buffer", key, i);
+               strcpy(&usend_msg.envbuf[bufpos], key);
+               bufpos += keylen + 1;
+       }
+       /* 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;
+       dbg("usend_msg_len=%i", usend_msg_len);
 
        /* If we can't send, try to start daemon and resend message */
-       loop = UDEVSEND_CONNECT_RETRY;
-       while (loop--) {
-               retval = sendto(sock, &msg, sizeof(struct hotplug_msg), 0,
-                               (struct sockaddr *)&saddr, addrlen);
+       loop = SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND;
+       while (--loop) {
+               retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
                if (retval != -1) {
                        retval = 0;
                        goto exit;
                }
 
                if (errno != ECONNREFUSED) {
-                       dbg("error sending message");
+                       dbg("error sending message (%s)", strerror(errno));
                        goto fallback;
                }
 
                if (!started_daemon) {
-                       info("starting udevd daemon");
+                       dbg("try to start udevd daemon");
                        retval = start_daemon();
                        if (retval) {
-                               info("error starting daemon");
+                               dbg("error starting daemon");
                                goto fallback;
                        }
-                       dbg("daemon started");
+                       dbg("udevd daemon started");
                        started_daemon = 1;
                } else {
-                       dbg("retry to connect %d", UDEVSEND_CONNECT_RETRY - loop);
-                       tspec.tv_sec = 0;
-                       tspec.tv_nsec = 100000000;  /* 100 millisec */
-                       nanosleep(&tspec, NULL);
+                       dbg("retry to connect %d", SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND - loop);
+                       usleep(1000 * 1000 / SEND_WAIT_LOOP_PER_SECOND);
                }
        }
 
@@ -215,5 +214,7 @@ exit:
        if (sock != -1)
                close(sock);
 
+       logging_close();
+
        return retval;
 }