implemented user id switching

some locking fixups


git-svn-id: file:///home/lennart/svn/public/ivam2/trunk@24 dbf6933d-3bce-0310-9bcc-ed052ba35b35

6 files changed, 112 insertions, 13 deletions

diff --git a/conf/msntab b/conf/msntab
index 251e906..16d8e5e 100644
--- a/conf/msntab
+++ b/conf/msntab
@@ -1,6 +1,6 @@
 # local MSN     remote MSN      options         action
 
-41264179         *        rings=0,pipehack       ivam-autobox
+#41264179         *        rings=0,pipehack       ivam-autobox
 
 #41264179        41264177        rings=0         ivam-dialup --pin=4711 ppp0
 #*               41264179        rings=0         @hangup
diff --git a/doc/TODO b/doc/TODO
index 97e6c8f..c9aad71 100644
--- a/doc/TODO
+++ b/doc/TODO
@@ -1,13 +1,20 @@
+post 1.0:
+
 * implement shbuf support
-* uid switching support
-* autoconf
-* documentation
+* uid switching for each client
 * regexp support
 * @same support
-* uid switching for each client
+
+pre 1.0:
+
+* autoconf
+* documentation
 * init script
-* mail on successful mailbox creation in ivam-autobox
 
+done:
+
+* uid switching support (DONE)
+* mail on successful mailbox creation in ivam-autobox (DONE)
 * --no-record --record-only (for voicebox) (DONE)
 * make it a daemon (DONE)
 * newmessage script (DONE)
diff --git a/src/ivamd.ggo b/src/ivamd.ggo
index 67e6f7e..ca280a4 100644
--- a/src/ivamd.ggo
+++ b/src/ivamd.ggo
@@ -27,3 +27,4 @@ option "check" c "Check if the daemon is currently running" flag off
 option "channels" C "Specify how many channels to allocate, defaults to 2" int default="2" no
 option "msntab" T "Specify non standard msntab file" string no
 option "listen" L "Specify a glob pattern matchin the MSNs to listen on" string no
+option "no-drop-root" - "Do not drop root priviliges" flag off
diff --git a/src/lock.c b/src/lock.c
index 42ad213..efce0bb 100644
--- a/src/lock.c
+++ b/src/lock.c
@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <inttypes.h>
+#include <pwd.h>
 
 #include <libdaemon/dlog.h>
 
@@ -35,6 +36,7 @@ int device_lock(const char *dev) {
     int fd;
     const char *path, *temp;
     char buf[100];
+    char uidbuf[32];
 
     if (stat(LOCK_PATH, &st) != 0 || !S_ISDIR(st.st_mode)) {
         daemon_log(LOG_ERR, "Failed to lock device, directory "LOCK_PATH" not existent.");
@@ -45,6 +47,9 @@ int device_lock(const char *dev) {
     temp = tempfile(path);
 
     for (;;) {
+        mode_t u;
+        struct passwd* pw;
+        char *username;
         
         if ((fd = open(path, O_RDONLY)) < 0) {
             if (errno != ENOENT) {
@@ -87,18 +92,33 @@ int device_lock(const char *dev) {
                 }
             }
         }
+
+        u = umask(0033);
+        fd = open(temp, O_WRONLY | O_CREAT | O_EXCL, 0666);
+        umask(u);
         
-        if ((fd = open(temp, O_WRONLY | O_CREAT | O_EXCL, 0666)) < 0) {
+        if (fd < 0) {
             daemon_log(LOG_ERR, "Failed to create temporary lock file: %s", strerror(errno));
             return -1;
         }
 
+        if ((pw = getpwuid(target_uid)))
+            username = pw->pw_name;
+        else
+            snprintf(username = uidbuf, sizeof(uidbuf), "%lu", (unsigned long) target_uid);
+
         snprintf(buf, sizeof(buf), "%10lu %s %.20s\n", (unsigned long) getpid(), appname, username);
         if (loop_write(fd, buf, strlen(buf)) < 0) {
             daemon_log(LOG_ERR, "Failed to write to temporary lock file: %s", strerror(errno));
             close(fd);
             return -1;
         }
+
+        if (fchown(fd, target_uid, target_gid) < 0) {
+            daemon_log(LOG_ERR, "Failed to change owners of temporary lock file: %s", strerror(errno));
+            close(fd);
+            return -1;
+        }
     
         close(fd);
 
diff --git a/src/main.c b/src/main.c
index 204fc69..53f8e80 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,6 +2,9 @@
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/types.h>
 
 #include <libdaemon/dlog.h>
 #include <libdaemon/dfork.h>
@@ -15,9 +18,14 @@
 
 oop_source* event_source = NULL;
 struct gengetopt_args_info args;
-const char *appname = NULL, *username = NULL;
+const char *appname = NULL;
+
+uid_t target_uid = 0;
+gid_t target_gid = 0;
 
 #define DEFAULT_MSNTABLE "../conf/msntab"
+#define IVAM_USER "ivam"
+#define IVAM_GROUP "ivam"
 
 static void *oop_exit_cb(oop_source *source, int sig, void *user) {
     daemon_log(LOG_ERR, "Recieved signal %s", sig == SIGINT ? "SIGINT" : (sig == SIGTERM ? "SIGTERM" : "UNKNWON"));
@@ -42,11 +50,66 @@ static void *oop_dump_cb(oop_source *source, int sig, void *user) {
 }
 
 
+static int change_uid_gid(void) {
+    if (args.no_drop_root_flag)
+        return 0;
+        
+    if (initgroups(IVAM_USER, target_gid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change group list: %s", strerror(errno));
+        return -1;
+    }
+    
+    if (setgid(target_gid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change GID: %s", strerror(errno));
+        return -1;
+    }
+    
+    if (setuid(target_uid) != 0) {
+        daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno));
+        return -1;
+    }
+
+    daemon_log(LOG_INFO, "Successfully dropped root privileges.");
+    
+    return 0;
+}
+
+static int get_target_uid_gid(void) {
+    struct passwd *pw;
+    struct group * gr;
+
+    if (args.no_drop_root_flag) {
+        target_uid = getuid();
+        target_gid = getgid();
+        return 0;
+    }
+
+    if (!(pw = getpwnam(IVAM_USER))) {
+        daemon_log(LOG_ERR, "Failed to find user '%s'.", IVAM_USER);
+        return -1;
+    }
+
+    if (!(gr = getgrnam(IVAM_GROUP))) {
+        daemon_log(LOG_ERR, "Failed to find group '%s'.", IVAM_GROUP);
+        return -1;
+    }
+
+    target_uid = pw->pw_uid;
+    target_gid = gr->gr_gid;
+    
+    daemon_log(LOG_INFO, "Found user '%s' (UID %lu) and group '%s' (GID %lu).", IVAM_USER, (unsigned long) target_uid, IVAM_GROUP, (unsigned long) target_gid);
+
+    return 0;
+}
+
 int main_loop(void) {
     int r = -1, retval_sent = 0;
     oop_source_sys *sys = NULL;
 
     daemon_log(LOG_INFO, "Starting up.");
+
+    if (get_target_uid_gid() < 0)
+        goto finish;
     
     if (!(sys = oop_sys_new())) {
         daemon_log(LOG_ERR, "Failed to create system source.");
@@ -55,6 +118,12 @@ int main_loop(void) {
 
     event_source = oop_sys_source(sys);
     assert(event_source);
+    
+    if (modem_manager_init(args.channels_arg) < 0)
+        goto finish;
+
+    if (change_uid_gid() < 0)
+        goto finish;
 
     if (child_process_init() < 0)
         goto finish;
@@ -62,9 +131,6 @@ int main_loop(void) {
     if (msntab_load(args.msntab_arg ? args.msntab_arg : DEFAULT_MSNTABLE) < 0)
         goto finish;
 
-    if (modem_manager_init(args.channels_arg) < 0)
-        goto finish;
-
     event_source->on_signal(event_source, SIGINT, oop_exit_cb, NULL);
     event_source->on_signal(event_source, SIGTERM, oop_exit_cb, NULL);
     event_source->on_signal(event_source, SIGHUP, oop_reload_cb, NULL);
@@ -177,7 +243,9 @@ int main(int argc, char*argv[]) {
 
     ret = main_loop() < 0 ? 1 : 0;
 
-    daemon_pid_file_remove();
+    if (daemon_pid_file_remove() < 0)
+        daemon_log(LOG_WARNING, "Failed to remove PID file (%s).", strerror(errno));
+
     return ret;
 }
 
diff --git a/src/main.h b/src/main.h
index c23d87d..6ceb7f2 100644
--- a/src/main.h
+++ b/src/main.h
@@ -7,8 +7,11 @@
 
 extern oop_source* event_source;
 
-extern const char *appname, *username;
+extern const char *appname;
 
 extern struct gengetopt_args_info args;
 
+extern uid_t target_uid;
+extern gid_t target_gid;
+
 #endif