reset: update cache-tree data when appropriate
[gitweb.git] / daemon.c
index daa4c8e8c95924c6fb446884b3ed44c454425b54..fa283003ea8809a2defc63f3b36cebe135028ddb 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -1,8 +1,9 @@
 #include "cache.h"
 #include "pkt-line.h"
 #include "exec_cmd.h"
-
-#include <syslog.h>
+#include "run-command.h"
+#include "strbuf.h"
+#include "string-list.h"
 
 #ifndef HOST_NAME_MAX
 #define HOST_NAME_MAX 256
 #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"
-"           [--timeout=n] [--init-timeout=n] [--max-connections=n]\n"
-"           [--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"
-"           [--[enable|disable|allow-override|forbid-override]=service]\n"
-"           [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
-"                      [--user=user [--group=group]]\n"
-"           [directory...]";
+"           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
+"           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
+"           [--user-path | --user-path=<path>]\n"
+"           [--interpolated-path=<path>]\n"
+"           [--reuseaddr] [--pid-file=<file>]\n"
+"           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
+"           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
+"                      [--detach] [--user=<user> [--group=<group>]]\n"
+"           [<directory>...]";
 
 /* List of acceptable pathname prefixes */
 static char **ok_paths;
@@ -66,15 +72,18 @@ 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);
        }
 }
 
+__attribute__((format (printf, 1, 2)))
 static void logerror(const char *err, ...)
 {
        va_list params;
@@ -83,6 +92,7 @@ static void logerror(const char *err, ...)
        va_end(params);
 }
 
+__attribute__((format (printf, 1, 2)))
 static void loginfo(const char *err, ...)
 {
        va_list params;
@@ -99,63 +109,16 @@ static void NORETURN daemon_die(const char *err, va_list params)
        exit(1);
 }
 
-static int avoid_alias(char *p)
-{
-       int sl, ndot;
-
-       /*
-        * This resurrects the belts and suspenders paranoia check by HPA
-        * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
-        * does not do getcwd() based path canonicalizations.
-        *
-        * sl becomes true immediately after seeing '/' and continues to
-        * be true as long as dots continue after that without intervening
-        * non-dot character.
-        */
-       if (!p || (*p != '/' && *p != '~'))
-               return -1;
-       sl = 1; ndot = 0;
-       p++;
-
-       while (1) {
-               char ch = *p++;
-               if (sl) {
-                       if (ch == '.')
-                               ndot++;
-                       else if (ch == '/') {
-                               if (ndot < 3)
-                                       /* reject //, /./ and /../ */
-                                       return -1;
-                               ndot = 0;
-                       }
-                       else if (ch == 0) {
-                               if (0 < ndot && ndot < 3)
-                                       /* reject /.$ and /..$ */
-                                       return -1;
-                               return 0;
-                       }
-                       else
-                               sl = ndot = 0;
-               }
-               else if (ch == 0)
-                       return 0;
-               else if (ch == '/') {
-                       sl = 1;
-                       ndot = 0;
-               }
-       }
-}
-
-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;
 
-       if (avoid_alias(dir)) {
+       if (daemon_avoid_alias(dir)) {
                logerror("'%s': aliased", dir);
                return NULL;
        }
@@ -184,16 +147,14 @@ static char *path_ok(char *directory)
        }
        else if (interpolated_path && saw_extended_args) {
                struct strbuf expanded_path = STRBUF_INIT;
-               struct strbuf_expand_dict_entry dict[] = {
-                       { "H", hostname },
-                       { "CH", canon_hostname },
-                       { "IP", ip_address },
-                       { "P", tcp_port },
-                       { "D", directory },
-                       { "%", "%" },
-                       { NULL }
-               };
-
+               struct strbuf_expand_dict_entry dict[6];
+
+               dict[0].placeholder = "H"; dict[0].value = hostname;
+               dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
+               dict[2].placeholder = "IP"; dict[2].value = ip_address;
+               dict[3].placeholder = "P"; dict[3].value = tcp_port;
+               dict[4].placeholder = "D"; dict[4].value = directory;
+               dict[5].placeholder = NULL; dict[5].value = NULL;
                if (*dir != '/') {
                        /* Allow only absolute */
                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
@@ -287,6 +248,14 @@ 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 int run_service(char *dir, struct daemon_service *service)
 {
        const char *path;
@@ -297,11 +266,11 @@ 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.
@@ -317,7 +286,7 @@ 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) {
@@ -331,7 +300,7 @@ 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");
        }
 
        /*
@@ -343,28 +312,68 @@ static int run_service(char *dir, struct daemon_service *service)
        return service->fn();
 }
 
+static void copy_to_log(int fd)
+{
+       struct strbuf line = STRBUF_INIT;
+       FILE *fp;
+
+       fp = fdopen(fd, "r");
+       if (fp == NULL) {
+               logerror("fdopen of error channel failed");
+               close(fd);
+               return;
+       }
+
+       while (strbuf_getline(&line, fp, '\n') != EOF) {
+               logerror("%s", line.buf);
+               strbuf_setlen(&line, 0);
+       }
+
+       strbuf_release(&line);
+       fclose(fp);
+}
+
+static int run_service_command(const char **argv)
+{
+       struct child_process cld;
+
+       memset(&cld, 0, sizeof(cld));
+       cld.argv = argv;
+       cld.git_cmd = 1;
+       cld.err = -1;
+       if (start_command(&cld))
+               return -1;
+
+       close(0);
+       close(1);
+
+       copy_to_log(cld.err);
+
+       return finish_command(&cld);
+}
+
 static int upload_pack(void)
 {
        /* Timeout as string */
        char timeout_buf[64];
+       const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
 
-       snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
+       argv[2] = timeout_buf;
 
-       /* git-upload-pack only ever reads stuff, so this is safe */
-       execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
-       return -1;
+       snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
+       return run_service_command(argv);
 }
 
 static int upload_archive(void)
 {
-       execl_git_cmd("upload-archive", ".", NULL);
-       return -1;
+       static const char *argv[] = { "upload-archive", ".", NULL };
+       return run_service_command(argv);
 }
 
 static int receive_pack(void)
 {
-       execl_git_cmd("receive-pack", ".", NULL);
-       return -1;
+       static const char *argv[] = { "receive-pack", ".", NULL };
+       return run_service_command(argv);
 }
 
 static struct daemon_service daemon_service[] = {
@@ -405,27 +414,53 @@ static char *xstrdup_tolower(const char *str)
        return dup;
 }
 
+static void parse_host_and_port(char *hostport, char **host,
+       char **port)
+{
+       if (*hostport == '[') {
+               char *end;
+
+               end = strchr(hostport, ']');
+               if (!end)
+                       die("Invalid request ('[' without ']')");
+               *end = '\0';
+               *host = hostport + 1;
+               if (!end[1])
+                       *port = NULL;
+               else if (end[1] == ':')
+                       *port = end + 2;
+               else
+                       die("Garbage after end of host part");
+       } else {
+               *host = hostport;
+               *port = strrchr(hostport, ':');
+               if (*port) {
+                       **port = '\0';
+                       ++*port;
+               }
+       }
+}
+
 /*
- * Separate the "extra args" information as supplied by the client connection.
+ * Read the host as supplied by the client connection.
  */
-static void parse_extra_args(char *extra_args, int buflen)
+static void parse_host_arg(char *extra_args, int buflen)
 {
        char *val;
        int vallen;
        char *end = extra_args + buflen;
 
-       while (extra_args < end && *extra_args) {
+       if (extra_args < end && *extra_args) {
                saw_extended_args = 1;
                if (strncasecmp("host=", extra_args, 5) == 0) {
                        val = extra_args + 5;
                        vallen = strlen(val) + 1;
                        if (*val) {
                                /* Split <host>:<port> at colon. */
-                               char *host = val;
-                               char *port = strrchr(host, ':');
+                               char *host;
+                               char *port;
+                               parse_host_and_port(val, &host, &port);
                                if (port) {
-                                       *port = 0;
-                                       port++;
                                        free(tcp_port);
                                        tcp_port = xstrdup(port);
                                }
@@ -436,6 +471,8 @@ static void parse_extra_args(char *extra_args, int buflen)
                        /* On to the next one */
                        extra_args = val + vallen;
                }
+               if (extra_args < end && *extra_args)
+                       die("Invalid request");
        }
 
        /*
@@ -451,7 +488,7 @@ static void parse_extra_args(char *extra_args, int buflen)
                memset(&hints, 0, sizeof(hints));
                hints.ai_flags = AI_CANONNAME;
 
-               gai = getaddrinfo(hostname, 0, &hints, &ai);
+               gai = getaddrinfo(hostname, NULL, &hints, &ai);
                if (!gai) {
                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 
@@ -492,37 +529,14 @@ static void parse_extra_args(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));
@@ -545,7 +559,7 @@ static int execute(struct sockaddr *addr)
        hostname = canon_hostname = ip_address = tcp_port = NULL;
 
        if (len != pktlen)
-               parse_extra_args(line + len + 1, pktlen - len - 1);
+               parse_host_arg(line + len + 1, pktlen - len - 1);
 
        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
                struct daemon_service *s = &(daemon_service[i]);
@@ -565,49 +579,52 @@ static int execute(struct sockaddr *addr)
        return -1;
 }
 
+static int addrcmp(const struct sockaddr_storage *s1,
+    const struct sockaddr_storage *s2)
+{
+       const struct sockaddr *sa1 = (const struct sockaddr*) s1;
+       const struct sockaddr *sa2 = (const struct sockaddr*) s2;
+
+       if (sa1->sa_family != sa2->sa_family)
+               return sa1->sa_family - sa2->sa_family;
+       if (sa1->sa_family == AF_INET)
+               return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
+                   &((struct sockaddr_in *)s2)->sin_addr,
+                   sizeof(struct in_addr));
+#ifndef NO_IPV6
+       if (sa1->sa_family == AF_INET6)
+               return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
+                   &((struct sockaddr_in6 *)s2)->sin6_addr,
+                   sizeof(struct in6_addr));
+#endif
+       return 0;
+}
+
 static int max_connections = 32;
 
 static unsigned int live_children;
 
 static struct child {
        struct child *next;
-       pid_t pid;
+       struct child_process cld;
        struct sockaddr_storage address;
 } *firstborn;
 
-static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
+static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 {
        struct child *newborn, **cradle;
 
-       /*
-        * This must be xcalloc() -- we'll compare the whole sockaddr_storage
-        * but individual address may be shorter.
-        */
        newborn = xcalloc(1, sizeof(*newborn));
        live_children++;
-       newborn->pid = pid;
+       memcpy(&newborn->cld, cld, sizeof(*cld));
        memcpy(&newborn->address, addr, addrlen);
        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
-               if (!memcmp(&(*cradle)->address, &newborn->address,
-                           sizeof(newborn->address)))
+               if (!addrcmp(&(*cradle)->address, &newborn->address))
                        break;
        newborn->next = *cradle;
        *cradle = newborn;
 }
 
-static void remove_child(pid_t pid)
-{
-       struct child **cradle, *blanket;
-
-       for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
-               if (blanket->pid == pid) {
-                       *cradle = blanket->next;
-                       live_children--;
-                       free(blanket);
-                       break;
-               }
-}
-
 /*
  * This gets called if the number of connections grows
  * past "max_connections".
@@ -622,9 +639,8 @@ static void kill_some_child(void)
                return;
 
        for (; (next = blanket->next); blanket = next)
-               if (!memcmp(&blanket->address, &next->address,
-                           sizeof(next->address))) {
-                       kill(blanket->pid, SIGTERM);
+               if (!addrcmp(&blanket->address, &next->address)) {
+                       kill(blanket->cld.pid, SIGTERM);
                        break;
                }
 }
@@ -634,18 +650,28 @@ static void check_dead_children(void)
        int status;
        pid_t pid;
 
-       while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
-               const char *dead = "";
-               remove_child(pid);
-               if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
-                       dead = " (with error)";
-               loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
-       }
+       struct child **cradle, *blanket;
+       for (cradle = &firstborn; (blanket = *cradle);)
+               if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
+                       const char *dead = "";
+                       if (status)
+                               dead = " (with error)";
+                       loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
+
+                       /* remove the child */
+                       *cradle = blanket->next;
+                       live_children--;
+                       free(blanket);
+               } else
+                       cradle = &blanket->next;
 }
 
-static void handle(int incoming, struct sockaddr *addr, int addrlen)
+static char **cld_argv;
+static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 {
-       pid_t pid;
+       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();
@@ -658,22 +684,37 @@ static void handle(int incoming, struct sockaddr *addr, int addrlen)
                }
        }
 
-       if ((pid = fork())) {
-               close(incoming);
-               if (pid < 0) {
-                       logerror("Couldn't fork %s", strerror(errno));
-                       return;
-               }
+       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;
 
-               add_child(pid, addr, addrlen);
-               return;
+               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
        }
 
-       dup2(incoming, 0);
-       dup2(incoming, 1);
-       close(incoming);
+       cld.env = (const char **)env;
+       cld.argv = (const char **)cld_argv;
+       cld.in = incoming;
+       cld.out = dup(incoming);
 
-       exit(execute(addr));
+       if (start_command(&cld))
+               logerror("unable to fork");
+       else
+               add_child(&cld, addr, addrlen);
+       close(incoming);
 }
 
 static void child_handler(int signo)
@@ -696,11 +737,40 @@ static int set_reuse_addr(int sockfd)
                          &on, sizeof(on));
 }
 
+struct socketlist {
+       int *list;
+       size_t nr;
+       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 socksetup(char *listen_addr, int listen_port, int **socklist_p)
+static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 {
-       int socknum = 0, *socklist = NULL;
+       int socknum = 0;
        int maxfd = -1;
        char pbuf[NI_MAXSERV];
        struct addrinfo hints, *ai0, *ai;
@@ -715,8 +785,10 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
        hints.ai_flags = AI_PASSIVE;
 
        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
-       if (gai)
-               die("getaddrinfo() failed: %s", gai_strerror(gai));
+       if (gai) {
+               logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
+               return 0;
+       }
 
        for (ai = ai0; ai; ai = ai->ai_next) {
                int sockfd;
@@ -740,15 +812,22 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 #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 */
                }
@@ -757,8 +836,9 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
                if (flags >= 0)
                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 
-               socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
-               socklist[socknum++] = sockfd;
+               ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
+               socklist->list[socklist->nr++] = sockfd;
+               socknum++;
 
                if (maxfd < sockfd)
                        maxfd = sockfd;
@@ -766,13 +846,12 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 
        freeaddrinfo(ai0);
 
-       *socklist_p = socklist;
        return socknum;
 }
 
 #else /* NO_IPV6 */
 
-static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
+static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 {
        struct sockaddr_in sin;
        int sockfd;
@@ -795,16 +874,23 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
                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;
        }
@@ -813,22 +899,39 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
        if (flags >= 0)
                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 
-       *socklist_p = xmalloc(sizeof(int));
-       **socklist_p = sockfd;
+       ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
+       socklist->list[socklist->nr++] = sockfd;
        return 1;
 }
 
 #endif
 
-static int service_loop(int socknum, int *socklist)
+static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
+{
+       if (!listen_addr->nr)
+               setup_named_sock(NULL, listen_port, socklist);
+       else {
+               int i, socknum;
+               for (i = 0; i < listen_addr->nr; i++) {
+                       socknum = setup_named_sock(listen_addr->items[i].string,
+                                                  listen_port, socklist);
+
+                       if (socknum == 0)
+                               logerror("unable to allocate any listen sockets for host %s on port %u",
+                                        listen_addr->items[i].string, listen_port);
+               }
+       }
+}
+
+static int service_loop(struct socketlist *socklist)
 {
        struct pollfd *pfd;
        int i;
 
-       pfd = xcalloc(socknum, sizeof(struct pollfd));
+       pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
 
-       for (i = 0; i < socknum; i++) {
-               pfd[i].fd = socklist[i];
+       for (i = 0; i < socklist->nr; i++) {
+               pfd[i].fd = socklist->list[i];
                pfd[i].events = POLLIN;
        }
 
@@ -839,7 +942,7 @@ static int service_loop(int socknum, int *socklist)
 
                check_dead_children();
 
-               if (poll(pfd, socknum, -1) < 0) {
+               if (poll(pfd, socklist->nr, -1) < 0) {
                        if (errno != EINTR) {
                                logerror("Poll failed, resuming: %s",
                                      strerror(errno));
@@ -848,11 +951,17 @@ static int service_loop(int socknum, int *socklist)
                        continue;
                }
 
-               for (i = 0; i < socknum; i++) {
+               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:
@@ -860,10 +969,10 @@ static int service_loop(int socknum, int *socklist)
                                        case ECONNABORTED:
                                                continue;
                                        default:
-                                               die("accept returned %s", strerror(errno));
+                                               die_errno("accept returned");
                                        }
                                }
-                               handle(incoming, (struct sockaddr *)&ss, sslen);
+                               handle(incoming, &ss.sa, sslen);
                        }
                }
        }
@@ -876,65 +985,118 @@ static void sanitize_stdfds(void)
        while (fd != -1 && fd < 2)
                fd = dup(fd);
        if (fd == -1)
-               die("open /dev/null or dup failed: %s", strerror(errno));
+               die_errno("open /dev/null or dup failed");
        if (fd > 2)
                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()) {
                case 0:
                        break;
                case -1:
-                       die("fork failed: %s", strerror(errno));
+                       die_errno("fork failed");
                default:
                        exit(0);
        }
        if (setsid() == -1)
-               die("setsid failed: %s", strerror(errno));
+               die_errno("setsid failed");
        close(0);
        close(1);
        close(2);
        sanitize_stdfds();
 }
+#endif
 
 static void store_pid(const char *path)
 {
        FILE *f = fopen(path, "w");
        if (!f)
-               die("cannot open pid file %s: %s", path, strerror(errno));
+               die_errno("cannot open pid file '%s'", path);
        if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
-               die("failed to write pid file %s: %s", path, strerror(errno));
+               die_errno("failed to write pid file '%s'", path);
 }
 
-static int serve(char *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)
 {
-       int socknum, *socklist;
+       struct socketlist socklist = { NULL, 0, 0 };
 
-       socknum = socksetup(listen_addr, listen_port, &socklist);
-       if (socknum == 0)
-               die("unable to allocate any listen sockets on host %s port %u",
-                   listen_addr, listen_port);
+       socksetup(listen_addr, listen_port, &socklist);
+       if (socklist.nr == 0)
+               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);
 
-       return service_loop(socknum, socklist);
+       return service_loop(&socklist);
 }
 
 int main(int argc, char **argv)
 {
        int listen_port = 0;
-       char *listen_addr = NULL;
-       int inetd_mode = 0;
+       struct string_list listen_addr = STRING_LIST_INIT_NODUP;
+       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_extract_argv0_path(argv[0]);
@@ -943,7 +1105,7 @@ int main(int argc, char **argv)
                char *arg = argv[i];
 
                if (!prefixcmp(arg, "--listen=")) {
-                       listen_addr = xstrdup_tolower(arg + 9);
+                       string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
                        continue;
                }
                if (!prefixcmp(arg, "--port=")) {
@@ -955,6 +1117,10 @@ int main(int argc, char **argv)
                                continue;
                        }
                }
+               if (!strcmp(arg, "--serve")) {
+                       serve_mode = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--inetd")) {
                        inetd_mode = 1;
                        log_syslog = 1;
@@ -1047,6 +1213,14 @@ 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;
@@ -1063,12 +1237,12 @@ 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))
+       if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
                die("--listen= and --port= are incompatible with --inetd");
        else if (listen_port == 0)
                listen_port = DEFAULT_GIT_PORT;
@@ -1076,21 +1250,8 @@ 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");
@@ -1100,20 +1261,13 @@ int main(int argc, char **argv)
                    base_path);
 
        if (inetd_mode) {
-               struct sockaddr_storage ss;
-               struct sockaddr *peer = (struct sockaddr *)&ss;
-               socklen_t slen = sizeof(ss);
-
                if (!freopen("/dev/null", "w", stderr))
-                       die("failed to redirect stderr to /dev/null: %s",
-                           strerror(errno));
-
-               if (getpeername(0, peer, &slen))
-                       peer = NULL;
-
-               return execute(peer);
+                       die_errno("failed to redirect stderr to /dev/null");
        }
 
+       if (inetd_mode || serve_mode)
+               return execute();
+
        if (detach) {
                daemonize();
                loginfo("Ready to rumble");
@@ -1124,5 +1278,13 @@ int main(int argc, char **argv)
        if (pid_file)
                store_pid(pid_file);
 
-       return serve(listen_addr, listen_port, pass, gid);
+       /* prepare argv for serving-processes */
+       cld_argv = xmalloc(sizeof (char *) * (argc + 2));
+       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, cred);
 }