X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fbus-proxyd%2Fbus-proxyd.c;h=b6b0056362f8f071af4092e67b2261b910f0dc65;hb=484adfd914504cd7e95867cea20ca7af71b888f2;hp=702f021a6bdcfed8df3082e4a7a53394b80fc546;hpb=a8a1a43f482af480c375a97921df6b42452c7092;p=elogind.git

diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c
index 702f021a6..b6b005636 100644
--- a/src/bus-proxyd/bus-proxyd.c
+++ b/src/bus-proxyd/bus-proxyd.c
@@ -29,7 +29,8 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
-#include <sys/poll.h>
+#include <poll.h>
+#include <sys/prctl.h>
 #include <stddef.h>
 #include <getopt.h>
 #include <pthread.h>
@@ -60,13 +61,15 @@ static char **arg_configuration = NULL;
 
 typedef struct {
         int fd;
+        SharedPolicy *policy;
+        uid_t bus_uid;
 } ClientContext;
 
 static ClientContext *client_context_free(ClientContext *c) {
         if (!c)
                 return NULL;
 
-        close(c->fd);
+        safe_close(c->fd);
         free(c);
 
         return NULL;
@@ -74,14 +77,14 @@ static ClientContext *client_context_free(ClientContext *c) {
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(ClientContext*, client_context_free);
 
-static int client_context_new(ClientContext **out, int fd) {
+static int client_context_new(ClientContext **out) {
         _cleanup_(client_context_freep) ClientContext *c = NULL;
 
         c = new0(ClientContext, 1);
         if (!c)
                 return log_oom();
 
-        c->fd = fd;
+        c->fd = -1;
 
         *out = c;
         c = NULL;
@@ -91,17 +94,26 @@ static int client_context_new(ClientContext **out, int fd) {
 static void *run_client(void *userdata) {
         _cleanup_(client_context_freep) ClientContext *c = userdata;
         _cleanup_(proxy_freep) Proxy *p = NULL;
+        char comm[16];
         int r;
 
         r = proxy_new(&p, c->fd, c->fd, arg_address);
         if (r < 0)
                 goto exit;
 
-        r = proxy_load_policy(p, arg_configuration);
+        c->fd = -1;
+
+        /* set comm to "p$PIDu$UID" and suffix with '*' if truncated */
+        r = snprintf(comm, sizeof(comm), "p" PID_FMT "u" UID_FMT, p->local_creds.pid, p->local_creds.uid);
+        if (r >= (ssize_t)sizeof(comm))
+                comm[sizeof(comm) - 2] = '*';
+        (void) prctl(PR_SET_NAME, comm);
+
+        r = proxy_set_policy(p, c->policy, arg_configuration);
         if (r < 0)
                 goto exit;
 
-        r = proxy_hello_policy(p, getuid());
+        r = proxy_hello_policy(p, c->bus_uid);
         if (r < 0)
                 goto exit;
 
@@ -111,22 +123,26 @@ exit:
         return NULL;
 }
 
-static int loop_clients(int accept_fd) {
+static int loop_clients(int accept_fd, uid_t bus_uid) {
+        _cleanup_(shared_policy_freep) SharedPolicy *sp = NULL;
         pthread_attr_t attr;
         int r;
 
         r = pthread_attr_init(&attr);
         if (r < 0) {
-                r = log_error_errno(errno, "Cannot initialize pthread attributes: %m");
-                goto exit;
+                return log_error_errno(errno, "Cannot initialize pthread attributes: %m");
         }
 
         r = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
         if (r < 0) {
                 r = log_error_errno(errno, "Cannot mark pthread attributes as detached: %m");
-                goto exit_attr;
+                goto finish;
         }
 
+        r = shared_policy_new(&sp);
+        if (r < 0)
+                goto finish;
+
         for (;;) {
                 ClientContext *c;
                 pthread_t tid;
@@ -138,16 +154,20 @@ static int loop_clients(int accept_fd) {
                                 continue;
 
                         r = log_error_errno(errno, "accept4() failed: %m");
-                        break;
+                        goto finish;
                 }
 
-                r = client_context_new(&c, fd);
+                r = client_context_new(&c);
                 if (r < 0) {
                         log_oom();
                         close(fd);
                         continue;
                 }
 
+                c->fd = fd;
+                c->policy = sp;
+                c->bus_uid = bus_uid;
+
                 r = pthread_create(&tid, &attr, run_client, c);
                 if (r < 0) {
                         log_error("Cannot spawn thread: %m");
@@ -156,9 +176,8 @@ static int loop_clients(int accept_fd) {
                 }
         }
 
-exit_attr:
+finish:
         pthread_attr_destroy(&attr);
-exit:
         return r;
 }
 
@@ -213,17 +232,11 @@ static int parse_argv(int argc, char *argv[]) {
                         puts(SYSTEMD_FEATURES);
                         return 0;
 
-                case ARG_ADDRESS: {
-                        char *a;
-
-                        a = strdup(optarg);
-                        if (!a)
+                case ARG_ADDRESS:
+                        r = free_and_strdup(&arg_address, optarg);
+                        if (r < 0)
                                 return log_oom();
-
-                        free(arg_address);
-                        arg_address = a;
                         break;
-                }
 
                 case ARG_CONFIGURATION:
                         r = strv_extend(&arg_configuration, optarg);
@@ -276,11 +289,31 @@ static int parse_argv(int argc, char *argv[]) {
 
 int main(int argc, char *argv[]) {
         int r, accept_fd;
+        uid_t uid, bus_uid;
+        gid_t gid;
 
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_parse_environment();
         log_open();
 
+        bus_uid = getuid();
+
+        if (geteuid() == 0) {
+                const char *user = "systemd-bus-proxy";
+
+                r = get_user_creds(&user, &uid, &gid, NULL, NULL);
+                if (r < 0) {
+                        log_error_errno(r, "Cannot resolve user name %s: %m", user);
+                        goto finish;
+                }
+
+                r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER);
+                if (r < 0) {
+                        log_error_errno(r, "Cannot drop privileges: %m");
+                        goto finish;
+                }
+        }
+
         r = parse_argv(argc, argv);
         if (r <= 0)
                 goto finish;
@@ -292,13 +325,14 @@ int main(int argc, char *argv[]) {
         }
 
         accept_fd = SD_LISTEN_FDS_START;
+
         r = fd_nonblock(accept_fd, false);
         if (r < 0) {
                 log_error_errno(r, "Cannot mark accept-fd non-blocking: %m");
                 goto finish;
         }
 
-        r = loop_clients(accept_fd);
+        r = loop_clients(accept_fd, bus_uid);
 
 finish:
         sd_notify(false,