push: require force for refs under refs/tags/
[gitweb.git] / daemon.c
index 40595933bea6ddc516a49f7bd5de29b3bb91db16..4602b46a5c39e1d501143ab4e95b55aff5c8f23b 100644 (file)
--- a/daemon.c
+++ b/daemon.c
 #define NI_MAXSERV 32
 #endif
 
+#ifdef NO_INITGROUPS
+#define initgroups(x, y) (0) /* nothing */
+#endif
+
 static int log_syslog;
 static int verbose;
 static int reuseaddr;
+static int informative_errors;
 
 static const char daemon_usage[] =
 "git daemon [--verbose] [--syslog] [--export-all]\n"
@@ -23,10 +28,11 @@ static const char daemon_usage[] =
 "           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
 "           [--user-path | --user-path=<path>]\n"
 "           [--interpolated-path=<path>]\n"
-"           [--reuseaddr] [--detach] [--pid-file=<file>]\n"
+"           [--reuseaddr] [--pid-file=<file>]\n"
 "           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
+"           [--access-hook=<path>]\n"
 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
-"                      [--user=<user> [--group=<group>]]\n"
+"                      [--detach] [--user=<user> [--group=<group>]]\n"
 "           [<directory>...]";
 
 /* List of acceptable pathname prefixes */
@@ -67,12 +73,14 @@ static void logreport(int priority, const char *err, va_list params)
                syslog(priority, "%s", buf);
        } else {
                /*
-                * Since stderr is set to linebuffered mode, the
+                * Since stderr is set to buffered mode, the
                 * logging of different processes will not overlap
+                * unless they overflow the (rather big) buffers.
                 */
                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
                vfprintf(stderr, err, params);
                fputc('\n', stderr);
+               fflush(stderr);
        }
 }
 
@@ -102,11 +110,11 @@ static void NORETURN daemon_die(const char *err, va_list params)
        exit(1);
 }
 
-static char *path_ok(char *directory)
+static const char *path_ok(char *directory)
 {
        static char rpath[PATH_MAX];
        static char interp_path[PATH_MAX];
-       char *path;
+       const char *path;
        char *dir;
 
        dir = directory;
@@ -241,6 +249,79 @@ static int git_daemon_config(const char *var, const char *value, void *cb)
        return 0;
 }
 
+static int daemon_error(const char *dir, const char *msg)
+{
+       if (!informative_errors)
+               msg = "access denied or repository not exported";
+       packet_write(1, "ERR %s: %s", msg, dir);
+       return -1;
+}
+
+static char *access_hook;
+
+static int run_access_hook(struct daemon_service *service, const char *dir, const char *path)
+{
+       struct child_process child;
+       struct strbuf buf = STRBUF_INIT;
+       const char *argv[8];
+       const char **arg = argv;
+       char *eol;
+       int seen_errors = 0;
+
+#define STRARG(x) ((x) ? (x) : "")
+       *arg++ = access_hook;
+       *arg++ = service->name;
+       *arg++ = path;
+       *arg++ = STRARG(hostname);
+       *arg++ = STRARG(canon_hostname);
+       *arg++ = STRARG(ip_address);
+       *arg++ = STRARG(tcp_port);
+       *arg = NULL;
+#undef STRARG
+
+       memset(&child, 0, sizeof(child));
+       child.use_shell = 1;
+       child.argv = argv;
+       child.no_stdin = 1;
+       child.no_stderr = 1;
+       child.out = -1;
+       if (start_command(&child)) {
+               logerror("daemon access hook '%s' failed to start",
+                        access_hook);
+               goto error_return;
+       }
+       if (strbuf_read(&buf, child.out, 0) < 0) {
+               logerror("failed to read from pipe to daemon access hook '%s'",
+                        access_hook);
+               strbuf_reset(&buf);
+               seen_errors = 1;
+       }
+       if (close(child.out) < 0) {
+               logerror("failed to close pipe to daemon access hook '%s'",
+                        access_hook);
+               seen_errors = 1;
+       }
+       if (finish_command(&child))
+               seen_errors = 1;
+
+       if (!seen_errors) {
+               strbuf_release(&buf);
+               return 0;
+       }
+
+error_return:
+       strbuf_ltrim(&buf);
+       if (!buf.len)
+               strbuf_addstr(&buf, "service rejected");
+       eol = strchr(buf.buf, '\n');
+       if (eol)
+               *eol = '\0';
+       errno = EACCES;
+       daemon_error(dir, buf.buf);
+       strbuf_release(&buf);
+       return -1;
+}
+
 static int run_service(char *dir, struct daemon_service *service)
 {
        const char *path;
@@ -251,11 +332,11 @@ static int run_service(char *dir, struct daemon_service *service)
        if (!enabled && !service->overridable) {
                logerror("'%s': service not enabled.", service->name);
                errno = EACCES;
-               return -1;
+               return daemon_error(dir, "service not enabled");
        }
 
        if (!(path = path_ok(dir)))
-               return -1;
+               return daemon_error(dir, "no such repository");
 
        /*
         * Security on the cheap.
@@ -271,7 +352,7 @@ static int run_service(char *dir, struct daemon_service *service)
        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
                logerror("'%s': repository not exported.", path);
                errno = EACCES;
-               return -1;
+               return daemon_error(dir, "repository not exported");
        }
 
        if (service->overridable) {
@@ -285,9 +366,16 @@ static int run_service(char *dir, struct daemon_service *service)
                logerror("'%s': service not enabled for '%s'",
                         service->name, path);
                errno = EACCES;
-               return -1;
+               return daemon_error(dir, "service not enabled");
        }
 
+       /*
+        * Optionally, a hook can choose to deny access to the
+        * repository depending on the phase of the moon.
+        */
+       if (access_hook && run_access_hook(service, dir, path))
+               return -1;
+
        /*
         * We'll ignore SIGTERM from now on, we have a
         * good client.
@@ -514,37 +602,14 @@ static void parse_host_arg(char *extra_args, int buflen)
 }
 
 
-static int execute(struct sockaddr *addr)
+static int execute(void)
 {
        static char line[1000];
        int pktlen, len, i;
+       char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 
-       if (addr) {
-               char addrbuf[256] = "";
-               int port = -1;
-
-               if (addr->sa_family == AF_INET) {
-                       struct sockaddr_in *sin_addr = (void *) addr;
-                       inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
-                       port = ntohs(sin_addr->sin_port);
-#ifndef NO_IPV6
-               } else if (addr && addr->sa_family == AF_INET6) {
-                       struct sockaddr_in6 *sin6_addr = (void *) addr;
-
-                       char *buf = addrbuf;
-                       *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
-                       inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
-                       strcat(buf, "]");
-
-                       port = ntohs(sin6_addr->sin6_port);
-#endif
-               }
-               loginfo("Connection from %s:%d", addrbuf, port);
-               setenv("REMOTE_ADDR", addrbuf, 1);
-       }
-       else {
-               unsetenv("REMOTE_ADDR");
-       }
+       if (addr)
+               loginfo("Connection from %s:%s", addr, port);
 
        alarm(init_timeout ? init_timeout : timeout);
        pktlen = packet_read_line(0, line, sizeof(line));
@@ -618,7 +683,7 @@ static struct child {
        struct sockaddr_storage address;
 } *firstborn;
 
-static void add_child(struct child_process *cld, struct sockaddr *addr, int addrlen)
+static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 {
        struct child *newborn, **cradle;
 
@@ -675,9 +740,11 @@ static void check_dead_children(void)
 }
 
 static char **cld_argv;
-static void handle(int incoming, struct sockaddr *addr, int addrlen)
+static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 {
-       struct child_process cld = { 0 };
+       struct child_process cld = { NULL };
+       char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
+       char *env[] = { addrbuf, portbuf, NULL };
 
        if (max_connections && live_children >= max_connections) {
                kill_some_child();
@@ -690,6 +757,28 @@ static void handle(int incoming, struct sockaddr *addr, int addrlen)
                }
        }
 
+       if (addr->sa_family == AF_INET) {
+               struct sockaddr_in *sin_addr = (void *) addr;
+               inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf + 12,
+                   sizeof(addrbuf) - 12);
+               snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
+                   ntohs(sin_addr->sin_port));
+#ifndef NO_IPV6
+       } else if (addr && addr->sa_family == AF_INET6) {
+               struct sockaddr_in6 *sin6_addr = (void *) addr;
+
+               char *buf = addrbuf + 12;
+               *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
+               inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf,
+                   sizeof(addrbuf) - 13);
+               strcat(buf, "]");
+
+               snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
+                   ntohs(sin6_addr->sin6_port));
+#endif
+       }
+
+       cld.env = (const char **)env;
        cld.argv = (const char **)cld_argv;
        cld.in = incoming;
        cld.out = dup(incoming);
@@ -727,6 +816,29 @@ struct socketlist {
        size_t alloc;
 };
 
+static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
+{
+#ifdef NO_IPV6
+       static char ip[INET_ADDRSTRLEN];
+#else
+       static char ip[INET6_ADDRSTRLEN];
+#endif
+
+       switch (family) {
+#ifndef NO_IPV6
+       case AF_INET6:
+               inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
+               break;
+#endif
+       case AF_INET:
+               inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
+               break;
+       default:
+               strcpy(ip, "<unknown>");
+       }
+       return ip;
+}
+
 #ifndef NO_IPV6
 
 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
@@ -773,15 +885,22 @@ static int setup_named_sock(char *listen_addr, int listen_port, struct socketlis
 #endif
 
                if (set_reuse_addr(sockfd)) {
+                       logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
                        close(sockfd);
                        continue;
                }
 
                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
+                       logerror("Could not bind to %s: %s",
+                                ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
+                                strerror(errno));
                        close(sockfd);
                        continue;       /* not fatal */
                }
                if (listen(sockfd, 5) < 0) {
+                       logerror("Could not listen to %s: %s",
+                                ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
+                                strerror(errno));
                        close(sockfd);
                        continue;       /* not fatal */
                }
@@ -828,16 +947,23 @@ static int setup_named_sock(char *listen_addr, int listen_port, struct socketlis
                return 0;
 
        if (set_reuse_addr(sockfd)) {
+               logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
                close(sockfd);
                return 0;
        }
 
        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
+               logerror("Could not listen to %s: %s",
+                        ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
+                        strerror(errno));
                close(sockfd);
                return 0;
        }
 
        if (listen(sockfd, 5) < 0) {
+               logerror("Could not listen to %s: %s",
+                        ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
+                        strerror(errno));
                close(sockfd);
                return 0;
        }
@@ -900,9 +1026,15 @@ static int service_loop(struct socketlist *socklist)
 
                for (i = 0; i < socklist->nr; i++) {
                        if (pfd[i].revents & POLLIN) {
-                               struct sockaddr_storage ss;
-                               unsigned int sslen = sizeof(ss);
-                               int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
+                               union {
+                                       struct sockaddr sa;
+                                       struct sockaddr_in sai;
+#ifndef NO_IPV6
+                                       struct sockaddr_in6 sai6;
+#endif
+                               } ss;
+                               socklen_t sslen = sizeof(ss);
+                               int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
                                if (incoming < 0) {
                                        switch (errno) {
                                        case EAGAIN:
@@ -913,7 +1045,7 @@ static int service_loop(struct socketlist *socklist)
                                                die_errno("accept returned");
                                        }
                                }
-                               handle(incoming, (struct sockaddr *)&ss, sslen);
+                               handle(incoming, &ss.sa, sslen);
                        }
                }
        }
@@ -931,6 +1063,62 @@ static void sanitize_stdfds(void)
                close(fd);
 }
 
+#ifdef NO_POSIX_GOODIES
+
+struct credentials;
+
+static void drop_privileges(struct credentials *cred)
+{
+       /* nothing */
+}
+
+static void daemonize(void)
+{
+       die("--detach not supported on this platform");
+}
+
+static struct credentials *prepare_credentials(const char *user_name,
+    const char *group_name)
+{
+       die("--user not supported on this platform");
+}
+
+#else
+
+struct credentials {
+       struct passwd *pass;
+       gid_t gid;
+};
+
+static void drop_privileges(struct credentials *cred)
+{
+       if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
+           setgid (cred->gid) || setuid(cred->pass->pw_uid)))
+               die("cannot drop privileges");
+}
+
+static struct credentials *prepare_credentials(const char *user_name,
+    const char *group_name)
+{
+       static struct credentials c;
+
+       c.pass = getpwnam(user_name);
+       if (!c.pass)
+               die("user not found - %s", user_name);
+
+       if (!group_name)
+               c.gid = c.pass->pw_gid;
+       else {
+               struct group *group = getgrnam(group_name);
+               if (!group)
+                       die("group not found - %s", group_name);
+
+               c.gid = group->gr_gid;
+       }
+
+       return &c;
+}
+
 static void daemonize(void)
 {
        switch (fork()) {
@@ -948,6 +1136,7 @@ static void daemonize(void)
        close(2);
        sanitize_stdfds();
 }
+#endif
 
 static void store_pid(const char *path)
 {
@@ -958,7 +1147,8 @@ static void store_pid(const char *path)
                die_errno("failed to write pid file '%s'", path);
 }
 
-static int serve(struct string_list *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
+static int serve(struct string_list *listen_addr, int listen_port,
+    struct credentials *cred)
 {
        struct socketlist socklist = { NULL, 0, 0 };
 
@@ -967,10 +1157,9 @@ static int serve(struct string_list *listen_addr, int listen_port, struct passwd
                die("unable to allocate any listen sockets on port %u",
                    listen_port);
 
-       if (pass && gid &&
-           (initgroups(pass->pw_name, gid) || setgid (gid) ||
-            setuid(pass->pw_uid)))
-               die("cannot drop privileges");
+       drop_privileges(cred);
+
+       loginfo("Ready to rumble");
 
        return service_loop(&socklist);
 }
@@ -982,11 +1171,11 @@ int main(int argc, char **argv)
        int serve_mode = 0, inetd_mode = 0;
        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
        int detach = 0;
-       struct passwd *pass = NULL;
-       struct group *group;
-       gid_t gid = 0;
+       struct credentials *cred = NULL;
        int i;
 
+       git_setup_gettext();
+
        git_extract_argv0_path(argv[0]);
 
        for (i = 1; i < argc; i++) {
@@ -1026,6 +1215,10 @@ int main(int argc, char **argv)
                        export_all_trees = 1;
                        continue;
                }
+               if (!prefixcmp(arg, "--access-hook=")) {
+                       access_hook = arg + 14;
+                       continue;
+               }
                if (!prefixcmp(arg, "--timeout=")) {
                        timeout = atoi(arg+10);
                        continue;
@@ -1101,6 +1294,14 @@ int main(int argc, char **argv)
                        make_service_overridable(arg + 18, 0);
                        continue;
                }
+               if (!prefixcmp(arg, "--informative-errors")) {
+                       informative_errors = 1;
+                       continue;
+               }
+               if (!prefixcmp(arg, "--no-informative-errors")) {
+                       informative_errors = 0;
+                       continue;
+               }
                if (!strcmp(arg, "--")) {
                        ok_paths = &argv[i+1];
                        break;
@@ -1117,10 +1318,10 @@ int main(int argc, char **argv)
                set_die_routine(daemon_die);
        } else
                /* avoid splitting a message in the middle */
-               setvbuf(stderr, NULL, _IOLBF, 0);
+               setvbuf(stderr, NULL, _IOFBF, 4096);
 
-       if (inetd_mode && (group_name || user_name))
-               die("--user and --group are incompatible with --inetd");
+       if (inetd_mode && (detach || group_name || user_name))
+               die("--detach, --user and --group are incompatible with --inetd");
 
        if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
                die("--listen= and --port= are incompatible with --inetd");
@@ -1130,21 +1331,8 @@ int main(int argc, char **argv)
        if (group_name && !user_name)
                die("--group supplied without --user");
 
-       if (user_name) {
-               pass = getpwnam(user_name);
-               if (!pass)
-                       die("user not found - %s", user_name);
-
-               if (!group_name)
-                       gid = pass->pw_gid;
-               else {
-                       group = getgrnam(group_name);
-                       if (!group)
-                               die("group not found - %s", group_name);
-
-                       gid = group->gr_gid;
-               }
-       }
+       if (user_name)
+               cred = prepare_credentials(user_name, group_name);
 
        if (strict_paths && (!ok_paths || !*ok_paths))
                die("option --strict-paths requires a whitelist");
@@ -1158,21 +1346,11 @@ int main(int argc, char **argv)
                        die_errno("failed to redirect stderr to /dev/null");
        }
 
-       if (inetd_mode || serve_mode) {
-               struct sockaddr_storage ss;
-               struct sockaddr *peer = (struct sockaddr *)&ss;
-               socklen_t slen = sizeof(ss);
-
-               if (getpeername(0, peer, &slen))
-                       return execute(NULL);
-               else
-                       return execute(peer);
-       }
+       if (inetd_mode || serve_mode)
+               return execute();
 
-       if (detach) {
+       if (detach)
                daemonize();
-               loginfo("Ready to rumble");
-       }
        else
                sanitize_stdfds();
 
@@ -1181,10 +1359,11 @@ int main(int argc, char **argv)
 
        /* prepare argv for serving-processes */
        cld_argv = xmalloc(sizeof (char *) * (argc + 2));
-       for (i = 0; i < argc; ++i)
-               cld_argv[i] = argv[i];
-       cld_argv[argc] = "--serve";
+       cld_argv[0] = argv[0];  /* git-daemon */
+       cld_argv[1] = "--serve";
+       for (i = 1; i < argc; ++i)
+               cld_argv[i+1] = argv[i];
        cld_argv[argc+1] = NULL;
 
-       return serve(&listen_addr, listen_port, pass, gid);
+       return serve(&listen_addr, listen_port, cred);
 }