X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fbus-proxyd%2Fbus-proxyd.c;h=07995ec83255c6147793a6e341045fbc1554e678;hb=9339db7187c61eb7ae7e6ffcddb2b2f2686954eb;hp=e095d61ffbd6a1dd8ce1b8c997b8324325fe22db;hpb=19befb2d5fc087f96e40ddc432b2cc9385666209;p=elogind.git

diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c
index e095d61ff..07995ec83 100644
--- a/src/bus-proxyd/bus-proxyd.c
+++ b/src/bus-proxyd/bus-proxyd.c
@@ -44,18 +44,24 @@
 #include "build.h"
 #include "strv.h"
 #include "def.h"
+#include "capability.h"
+#include "bus-policy.h"
 
-static const char *arg_address = DEFAULT_SYSTEM_BUS_PATH;
+static const char *arg_address = KERNEL_SYSTEM_BUS_PATH;
 static char *arg_command_line_buffer = NULL;
+static bool arg_drop_privileges = false;
+static char **arg_configuration = NULL;
 
 static int help(void) {
 
         printf("%s [OPTIONS...]\n\n"
                "Connect STDIO or a socket to a given bus address.\n\n"
-               "  -h --help              Show this help\n"
-               "     --version           Show package version\n"
-               "     --address=ADDRESS   Connect to the bus specified by ADDRESS\n"
-               "                         (default: " DEFAULT_SYSTEM_BUS_PATH ")\n",
+               "  -h --help               Show this help\n"
+               "     --version            Show package version\n"
+               "     --drop-privileges    Drop privileges\n"
+               "     --configuration=PATH Configuration file or directory\n"
+               "     --address=ADDRESS    Connect to the bus specified by ADDRESS\n"
+               "                         (default: " KERNEL_SYSTEM_BUS_PATH ")\n",
                program_invocation_short_name);
 
         return 0;
@@ -66,16 +72,20 @@ static int parse_argv(int argc, char *argv[]) {
         enum {
                 ARG_VERSION = 0x100,
                 ARG_ADDRESS,
+                ARG_DROP_PRIVILEGES,
+                ARG_CONFIGURATION,
         };
 
         static const struct option options[] = {
-                { "help",       no_argument,       NULL, 'h'            },
-                { "version",    no_argument,       NULL, ARG_VERSION    },
-                { "address",    required_argument, NULL, ARG_ADDRESS    },
-                { NULL,         0,                 NULL, 0              }
+                { "help",            no_argument,       NULL, 'h'                 },
+                { "version",         no_argument,       NULL, ARG_VERSION         },
+                { "address",         required_argument, NULL, ARG_ADDRESS         },
+                { "drop-privileges", no_argument,       NULL, ARG_DROP_PRIVILEGES },
+                { "configuration",   required_argument, NULL, ARG_CONFIGURATION   },
+                { NULL,              0,                 NULL, 0                   },
         };
 
-        int c;
+        int c, r;
 
         assert(argc >= 0);
         assert(argv);
@@ -97,6 +107,16 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_address = optarg;
                         break;
 
+                case ARG_DROP_PRIVILEGES:
+                        arg_drop_privileges = true;
+                        break;
+
+                case ARG_CONFIGURATION:
+                        r = strv_extend(&arg_configuration, optarg);
+                        if (r < 0)
+                                return log_oom();
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -440,7 +460,6 @@ static int peer_is_privileged(sd_bus *bus, sd_bus_message *m) {
         return false;
 }
 
-
 static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m) {
         int r;
 
@@ -1035,6 +1054,7 @@ int main(int argc, char *argv[]) {
         bool is_unix;
         struct ucred ucred = {};
         _cleanup_free_ char *peersec = NULL;
+        Policy policy = {};
 
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_parse_environment();
@@ -1044,6 +1064,14 @@ int main(int argc, char *argv[]) {
         if (r <= 0)
                 goto finish;
 
+        r = policy_load(&policy, arg_configuration);
+        if (r < 0) {
+                log_error("Failed to load policy: %s", strerror(-r));
+                goto finish;
+        }
+
+        /* policy_dump(&policy); */
+
         r = sd_listen_fds(0);
         if (r == 0) {
                 in_fd = STDIN_FILENO;
@@ -1065,6 +1093,22 @@ int main(int argc, char *argv[]) {
                 getpeersec(in_fd, &peersec);
         }
 
+        if (arg_drop_privileges) {
+                const char *user = "systemd-bus-proxy";
+                uid_t uid;
+                gid_t gid;
+
+                r = get_user_creds(&user, &uid, &gid, NULL, NULL);
+                if (r < 0) {
+                        log_error("Cannot resolve user name %s: %s", user, strerror(-r));
+                        goto finish;
+                }
+
+                r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER);
+                if (r < 0)
+                        goto finish;
+        }
+
         r = sd_bus_new(&a);
         if (r < 0) {
                 log_error("Failed to allocate bus: %s", strerror(-r));
@@ -1390,5 +1434,8 @@ finish:
         sd_bus_flush(a);
         sd_bus_flush(b);
 
+        policy_free(&policy);
+        strv_free(arg_configuration);
+
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }