Obey NO_C99_FORMAT in fast-import.c.
[gitweb.git] / daemon.c
index 012936f3bd76d9f9648ba9498b4126c7d6861e5c..66f8d6f03d91d7dfa4a164137ee0310ca26dc1aa 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -1,25 +1,28 @@
-#include <signal.h>
-#include <sys/wait.h>
-#include <sys/socket.h>
-#include <sys/time.h>
-#include <sys/poll.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <syslog.h>
-#include "pkt-line.h"
 #include "cache.h"
+#include "pkt-line.h"
 #include "exec_cmd.h"
+#include "interpolate.h"
+
+#include <syslog.h>
+
+#ifndef HOST_NAME_MAX
+#define HOST_NAME_MAX 256
+#endif
 
 static int log_syslog;
 static int verbose;
 static int reuseaddr;
 
 static const char daemon_usage[] =
-"git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
+"git-daemon [--verbose] [--syslog] [--export-all]\n"
 "           [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
 "           [--base-path=path] [--user-path | --user-path=path]\n"
-"           [--reuseaddr] [--detach] [--pid-file=file] [directory...]";
+"           [--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...]";
 
 /* List of acceptable pathname prefixes */
 static char **ok_paths;
@@ -30,6 +33,10 @@ static int export_all_trees;
 
 /* Take all paths relative to this one if non-NULL */
 static char *base_path;
+static char *interpolated_path;
+
+/* Flag indicating client sent extra args. */
+static int saw_extended_args;
 
 /* If defined, ~user notation is allowed and the string is inserted
  * after ~user/.  E.g. a request to git://host/~alice/frotz would
@@ -41,6 +48,27 @@ static const char *user_path;
 static unsigned int timeout;
 static unsigned int init_timeout;
 
+/*
+ * Static table for now.  Ugh.
+ * Feel free to make dynamic as needed.
+ */
+#define INTERP_SLOT_HOST       (0)
+#define INTERP_SLOT_CANON_HOST (1)
+#define INTERP_SLOT_IP         (2)
+#define INTERP_SLOT_PORT       (3)
+#define INTERP_SLOT_DIR                (4)
+#define INTERP_SLOT_PERCENT    (5)
+
+static struct interp interp_table[] = {
+       { "%H", 0},
+       { "%CH", 0},
+       { "%IP", 0},
+       { "%P", 0},
+       { "%D", 0},
+       { "%%", 0},
+};
+
+
 static void logreport(int priority, const char *err, va_list params)
 {
        /* We should do a single write so that it is atomic and output
@@ -74,7 +102,7 @@ static void logreport(int priority, const char *err, va_list params)
        buf[buflen++] = '\n';
        buf[buflen] = '\0';
 
-       write(2, buf, buflen);
+       write_in_full(2, buf, buflen);
 }
 
 static void logerror(const char *err, ...)
@@ -148,10 +176,14 @@ static int avoid_alias(char *p)
        }
 }
 
-static char *path_ok(char *dir)
+static char *path_ok(struct interp *itable)
 {
        static char rpath[PATH_MAX];
+       static char interp_path[PATH_MAX];
        char *path;
+       char *dir;
+
+       dir = itable[INTERP_SLOT_DIR].value;
 
        if (avoid_alias(dir)) {
                logerror("'%s': aliased", dir);
@@ -180,16 +212,27 @@ static char *path_ok(char *dir)
                        dir = rpath;
                }
        }
+       else if (interpolated_path && saw_extended_args) {
+               if (*dir != '/') {
+                       /* Allow only absolute */
+                       logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
+                       return NULL;
+               }
+
+               interpolate(interp_path, PATH_MAX, interpolated_path,
+                           interp_table, ARRAY_SIZE(interp_table));
+               loginfo("Interpolated dir '%s'", interp_path);
+
+               dir = interp_path;
+       }
        else if (base_path) {
                if (*dir != '/') {
                        /* Allow only absolute */
                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
                        return NULL;
                }
-               else {
-                       snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
-                       dir = rpath;
-               }
+               snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
+               dir = rpath;
        }
 
        path = enter_repo(dir, strict_paths);
@@ -229,15 +272,46 @@ static char *path_ok(char *dir)
        return NULL;            /* Fallthrough. Deny by default */
 }
 
-static int upload(char *dir)
+typedef int (*daemon_service_fn)(void);
+struct daemon_service {
+       const char *name;
+       const char *config_name;
+       daemon_service_fn fn;
+       int enabled;
+       int overridable;
+};
+
+static struct daemon_service *service_looking_at;
+static int service_enabled;
+
+static int git_daemon_config(const char *var, const char *value)
+{
+       if (!strncmp(var, "daemon.", 7) &&
+           !strcmp(var + 7, service_looking_at->config_name)) {
+               service_enabled = git_config_bool(var, value);
+               return 0;
+       }
+
+       /* we are not interested in parsing any other configuration here */
+       return 0;
+}
+
+static int run_service(struct interp *itable, struct daemon_service *service)
 {
-       /* Timeout as string */
-       char timeout_buf[64];
        const char *path;
+       int enabled = service->enabled;
 
-       loginfo("Request for '%s'", dir);
+       loginfo("Request %s for '%s'",
+               service->name,
+               itable[INTERP_SLOT_DIR].value);
 
-       if (!(path = path_ok(dir)))
+       if (!enabled && !service->overridable) {
+               logerror("'%s': service not enabled.", service->name);
+               errno = EACCES;
+               return -1;
+       }
+
+       if (!(path = path_ok(itable)))
                return -1;
 
        /*
@@ -257,12 +331,34 @@ static int upload(char *dir)
                return -1;
        }
 
+       if (service->overridable) {
+               service_looking_at = service;
+               service_enabled = -1;
+               git_config(git_daemon_config);
+               if (0 <= service_enabled)
+                       enabled = service_enabled;
+       }
+       if (!enabled) {
+               logerror("'%s': service not enabled for '%s'",
+                        service->name, path);
+               errno = EACCES;
+               return -1;
+       }
+
        /*
         * We'll ignore SIGTERM from now on, we have a
         * good client.
         */
        signal(SIGTERM, SIG_IGN);
 
+       return service->fn();
+}
+
+static int upload_pack(void)
+{
+       /* Timeout as string */
+       char timeout_buf[64];
+
        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 
        /* git-upload-pack only ever reads stuff, so this is safe */
@@ -270,10 +366,150 @@ static int upload(char *dir)
        return -1;
 }
 
+static int upload_archive(void)
+{
+       execl_git_cmd("upload-archive", ".", NULL);
+       return -1;
+}
+
+static int receive_pack(void)
+{
+       execl_git_cmd("receive-pack", ".", NULL);
+       return -1;
+}
+
+static struct daemon_service daemon_service[] = {
+       { "upload-archive", "uploadarch", upload_archive, 0, 1 },
+       { "upload-pack", "uploadpack", upload_pack, 1, 1 },
+       { "receive-pack", "receivepack", receive_pack, 0, 1 },
+};
+
+static void enable_service(const char *name, int ena) {
+       int i;
+       for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
+               if (!strcmp(daemon_service[i].name, name)) {
+                       daemon_service[i].enabled = ena;
+                       return;
+               }
+       }
+       die("No such service %s", name);
+}
+
+static void make_service_overridable(const char *name, int ena) {
+       int i;
+       for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
+               if (!strcmp(daemon_service[i].name, name)) {
+                       daemon_service[i].overridable = ena;
+                       return;
+               }
+       }
+       die("No such service %s", name);
+}
+
+/*
+ * Separate the "extra args" information as supplied by the client connection.
+ * Any resulting data is squirreled away in the given interpolation table.
+ */
+static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
+{
+       char *val;
+       int vallen;
+       char *end = extra_args + buflen;
+
+       while (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, ':');
+                               if (port) {
+                                       *port = 0;
+                                       port++;
+                                       interp_set_entry(table, INTERP_SLOT_PORT, port);
+                               }
+                               interp_set_entry(table, INTERP_SLOT_HOST, host);
+                       }
+
+                       /* On to the next one */
+                       extra_args = val + vallen;
+               }
+       }
+}
+
+void fill_in_extra_table_entries(struct interp *itable)
+{
+       char *hp;
+
+       /*
+        * Replace literal host with lowercase-ized hostname.
+        */
+       hp = interp_table[INTERP_SLOT_HOST].value;
+       if (!hp)
+               return;
+       for ( ; *hp; hp++)
+               *hp = tolower(*hp);
+
+       /*
+        * Locate canonical hostname and its IP address.
+        */
+#ifndef NO_IPV6
+       {
+               struct addrinfo hints;
+               struct addrinfo *ai, *ai0;
+               int gai;
+               static char addrbuf[HOST_NAME_MAX + 1];
+
+               memset(&hints, 0, sizeof(hints));
+               hints.ai_flags = AI_CANONNAME;
+
+               gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
+               if (!gai) {
+                       for (ai = ai0; ai; ai = ai->ai_next) {
+                               struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
+
+                               inet_ntop(AF_INET, &sin_addr->sin_addr,
+                                         addrbuf, sizeof(addrbuf));
+                               interp_set_entry(interp_table,
+                                                INTERP_SLOT_CANON_HOST, ai->ai_canonname);
+                               interp_set_entry(interp_table,
+                                                INTERP_SLOT_IP, addrbuf);
+                               break;
+                       }
+                       freeaddrinfo(ai0);
+               }
+       }
+#else
+       {
+               struct hostent *hent;
+               struct sockaddr_in sa;
+               char **ap;
+               static char addrbuf[HOST_NAME_MAX + 1];
+
+               hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
+
+               ap = hent->h_addr_list;
+               memset(&sa, 0, sizeof sa);
+               sa.sin_family = hent->h_addrtype;
+               sa.sin_port = htons(0);
+               memcpy(&sa.sin_addr, *ap, hent->h_length);
+
+               inet_ntop(hent->h_addrtype, &sa.sin_addr,
+                         addrbuf, sizeof(addrbuf));
+
+               interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
+               interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
+       }
+#endif
+}
+
+
 static int execute(struct sockaddr *addr)
 {
        static char line[1000];
-       int pktlen, len;
+       int pktlen, len, i;
 
        if (addr) {
                char addrbuf[256] = "";
@@ -307,11 +543,37 @@ static int execute(struct sockaddr *addr)
                loginfo("Extended attributes (%d bytes) exist <%.*s>",
                        (int) pktlen - len,
                        (int) pktlen - len, line + len + 1);
-       if (len && line[len-1] == '\n')
+       if (len && line[len-1] == '\n') {
                line[--len] = 0;
+               pktlen--;
+       }
 
-       if (!strncmp("git-upload-pack ", line, 16))
-               return upload(line+16);
+       /*
+        * Initialize the path interpolation table for this connection.
+        */
+       interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
+       interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
+
+       if (len != pktlen) {
+           parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
+           fill_in_extra_table_entries(interp_table);
+       }
+
+       for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
+               struct daemon_service *s = &(daemon_service[i]);
+               int namelen = strlen(s->name);
+               if (!strncmp("git-", line, 4) &&
+                   !strncmp(s->name, line + 4, namelen) &&
+                   line[namelen + 4] == ' ') {
+                       /*
+                        * Note: The directory here is probably context sensitive,
+                        * and might depend on the actual service being performed.
+                        */
+                       interp_set_entry(interp_table,
+                                        INTERP_SLOT_DIR, line + namelen + 5);
+                       return run_service(interp_table, s);
+               }
+       }
 
        logerror("Protocol error: '%s'", line);
        return -1;
@@ -504,29 +766,28 @@ static int set_reuse_addr(int sockfd)
 
 #ifndef NO_IPV6
 
-static int socksetup(int port, int **socklist_p)
+static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 {
        int socknum = 0, *socklist = NULL;
        int maxfd = -1;
        char pbuf[NI_MAXSERV];
-
        struct addrinfo hints, *ai0, *ai;
        int gai;
+       long flags;
 
-       sprintf(pbuf, "%d", port);
+       sprintf(pbuf, "%d", listen_port);
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = IPPROTO_TCP;
        hints.ai_flags = AI_PASSIVE;
 
-       gai = getaddrinfo(NULL, pbuf, &hints, &ai0);
+       gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
        if (gai)
                die("getaddrinfo() failed: %s\n", gai_strerror(gai));
 
        for (ai = ai0; ai; ai = ai->ai_next) {
                int sockfd;
-               int *newlist;
 
                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sockfd < 0)
@@ -560,11 +821,11 @@ static int socksetup(int port, int **socklist_p)
                        continue;       /* not fatal */
                }
 
-               newlist = realloc(socklist, sizeof(int) * (socknum + 1));
-               if (!newlist)
-                       die("memory allocation failed: %s", strerror(errno));
+               flags = fcntl(sockfd, F_GETFD, 0);
+               if (flags >= 0)
+                       fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
 
-               socklist = newlist;
+               socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
                socklist[socknum++] = sockfd;
 
                if (maxfd < sockfd)
@@ -579,20 +840,28 @@ static int socksetup(int port, int **socklist_p)
 
 #else /* NO_IPV6 */
 
-static int socksetup(int port, int **socklist_p)
+static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
 {
        struct sockaddr_in sin;
        int sockfd;
+       long flags;
+
+       memset(&sin, 0, sizeof sin);
+       sin.sin_family = AF_INET;
+       sin.sin_port = htons(listen_port);
+
+       if (listen_addr) {
+               /* Well, host better be an IP address here. */
+               if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
+                       return 0;
+       } else {
+               sin.sin_addr.s_addr = htonl(INADDR_ANY);
+       }
 
        sockfd = socket(AF_INET, SOCK_STREAM, 0);
        if (sockfd < 0)
                return 0;
 
-       memset(&sin, 0, sizeof sin);
-       sin.sin_family = AF_INET;
-       sin.sin_addr.s_addr = htonl(INADDR_ANY);
-       sin.sin_port = htons(port);
-
        if (set_reuse_addr(sockfd)) {
                close(sockfd);
                return 0;
@@ -608,6 +877,10 @@ static int socksetup(int port, int **socklist_p)
                return 0;
        }
 
+       flags = fcntl(sockfd, F_GETFD, 0);
+       if (flags >= 0)
+               fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
+
        *socklist_p = xmalloc(sizeof(int));
        **socklist_p = sockfd;
        return 1;
@@ -701,23 +974,33 @@ static void store_pid(const char *path)
        fclose(f);
 }
 
-static int serve(int port)
+static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
 {
        int socknum, *socklist;
 
-       socknum = socksetup(port, &socklist);
+       socknum = socksetup(listen_addr, listen_port, &socklist);
        if (socknum == 0)
-               die("unable to allocate any listen sockets on port %u", port);
+               die("unable to allocate any listen sockets on host %s port %u",
+                   listen_addr, listen_port);
+
+       if (pass && gid &&
+           (initgroups(pass->pw_name, gid) || setgid (gid) ||
+            setuid(pass->pw_uid)))
+               die("cannot drop privileges");
 
        return service_loop(socknum, socklist);
 }
 
 int main(int argc, char **argv)
 {
-       int port = DEFAULT_GIT_PORT;
+       int listen_port = 0;
+       char *listen_addr = NULL;
        int inetd_mode = 0;
-       const char *pid_file = NULL;
+       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;
        int i;
 
        /* Without this we cannot rely on waitpid() to tell
@@ -728,12 +1011,20 @@ int main(int argc, char **argv)
        for (i = 1; i < argc; i++) {
                char *arg = argv[i];
 
+               if (!strncmp(arg, "--listen=", 9)) {
+                   char *p = arg + 9;
+                   char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
+                   while (*p)
+                       *ph++ = tolower(*p++);
+                   *ph = 0;
+                   continue;
+               }
                if (!strncmp(arg, "--port=", 7)) {
                        char *end;
                        unsigned long n;
                        n = strtoul(arg+7, &end, 0);
                        if (arg[7] && !*end) {
-                               port = n;
+                               listen_port = n;
                                continue;
                        }
                }
@@ -770,6 +1061,10 @@ int main(int argc, char **argv)
                        base_path = arg+12;
                        continue;
                }
+               if (!strncmp(arg, "--interpolated-path=", 20)) {
+                       interpolated_path = arg+20;
+                       continue;
+               }
                if (!strcmp(arg, "--reuseaddr")) {
                        reuseaddr = 1;
                        continue;
@@ -791,6 +1086,30 @@ int main(int argc, char **argv)
                        log_syslog = 1;
                        continue;
                }
+               if (!strncmp(arg, "--user=", 7)) {
+                       user_name = arg + 7;
+                       continue;
+               }
+               if (!strncmp(arg, "--group=", 8)) {
+                       group_name = arg + 8;
+                       continue;
+               }
+               if (!strncmp(arg, "--enable=", 9)) {
+                       enable_service(arg + 9, 1);
+                       continue;
+               }
+               if (!strncmp(arg, "--disable=", 10)) {
+                       enable_service(arg + 10, 0);
+                       continue;
+               }
+               if (!strncmp(arg, "--allow-override=", 17)) {
+                       make_service_overridable(arg + 17, 1);
+                       continue;
+               }
+               if (!strncmp(arg, "--forbid-override=", 18)) {
+                       make_service_overridable(arg + 18, 0);
+                       continue;
+               }
                if (!strcmp(arg, "--")) {
                        ok_paths = &argv[i+1];
                        break;
@@ -802,6 +1121,33 @@ int main(int argc, char **argv)
                usage(daemon_usage);
        }
 
+       if (inetd_mode && (group_name || user_name))
+               die("--user and --group are incompatible with --inetd");
+
+       if (inetd_mode && (listen_port || listen_addr))
+               die("--listen= and --port= are incompatible with --inetd");
+       else if (listen_port == 0)
+               listen_port = DEFAULT_GIT_PORT;
+
+       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 (log_syslog) {
                openlog("git-daemon", 0, LOG_DAEMON);
                set_die_routine(daemon_die);
@@ -831,5 +1177,5 @@ int main(int argc, char **argv)
        if (pid_file)
                store_pid(pid_file);
 
-       return serve(port);
+       return serve(listen_addr, listen_port, pass, gid);
 }