Merge branch 'jc/lockfile' into next
[gitweb.git] / daemon.c
index 91b96569cd75c77cd4ee169c55be045daccf3908..776749e3432fca916981d73d04a1fa19ed3d88b8 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -9,13 +9,17 @@
 #include <syslog.h>
 #include "pkt-line.h"
 #include "cache.h"
+#include "exec_cmd.h"
 
 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"
-"           [--timeout=n] [--init-timeout=n] [--strict-paths] [directory...]";
+"           [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
+"           [--base-path=path] [--user-path | --user-path=path]\n"
+"           [--reuseaddr] [directory...]";
 
 /* List of acceptable pathname prefixes */
 static char **ok_paths = NULL;
@@ -24,6 +28,15 @@ static int strict_paths = 0;
 /* If this is set, git-daemon-export-ok is not required */
 static int export_all_trees = 0;
 
+/* Take all paths relative to this one if non-NULL */
+static char *base_path = NULL;
+
+/* If defined, ~user notation is allowed and the string is inserted
+ * after ~user/.  E.g. a request to git://host/~alice/frotz would
+ * go to /home/alice/pub_git/frotz with --user-path=pub_git.
+ */
+static char *user_path = NULL;
+
 /* Timeout, and initial timeout */
 static unsigned int timeout = 0;
 static unsigned int init_timeout = 0;
@@ -82,9 +95,98 @@ static void loginfo(const char *err, ...)
        va_end(params);
 }
 
+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 *dir)
 {
-       char *path = enter_repo(dir, strict_paths);
+       static char rpath[PATH_MAX];
+       char *path;
+
+       if (avoid_alias(dir)) {
+               logerror("'%s': aliased", dir);
+               return NULL;
+       }
+
+       if (*dir == '~') {
+               if (!user_path) {
+                       logerror("'%s': User-path not allowed", dir);
+                       return NULL;
+               }
+               if (*user_path) {
+                       /* Got either "~alice" or "~alice/foo";
+                        * rewrite them to "~alice/%s" or
+                        * "~alice/%s/foo".
+                        */
+                       int namlen, restlen = strlen(dir);
+                       char *slash = strchr(dir, '/');
+                       if (!slash)
+                               slash = dir + restlen;
+                       namlen = slash - dir;
+                       restlen -= namlen;
+                       loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
+                       snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
+                                namlen, dir, user_path, restlen, slash);
+                       dir = rpath;
+               }
+       }
+       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;
+               }
+       }
+
+       path = enter_repo(dir, strict_paths);
 
        if (!path) {
                logerror("'%s': unable to chdir or not a git archive", dir);
@@ -96,9 +198,11 @@ static char *path_ok(char *dir)
                int pathlen = strlen(path);
 
                /* The validation is done on the paths after enter_repo
-                * canonicalization, so whitelist should be written in
-                * terms of real pathnames (i.e. after ~user is expanded
-                * and symlinks resolved).
+                * appends optional {.git,.git/.git} and friends, but 
+                * it does not use getcwd().  So if your /pub is
+                * a symlink to /mnt/pub, you can whitelist /pub and
+                * do not have to say /mnt/pub.
+                * Do not say /pub/.
                 */
                for ( pp = ok_paths ; *pp ; pp++ ) {
                        int len = strlen(*pp);
@@ -156,7 +260,7 @@ static int upload(char *dir)
        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 
        /* git-upload-pack only ever reads stuff, so this is safe */
-       execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, ".", NULL);
+       execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
        return -1;
 }
 
@@ -375,6 +479,16 @@ static void child_handler(int signo)
        }
 }
 
+static int set_reuse_addr(int sockfd)
+{
+       int on = 1;
+
+       if (!reuseaddr)
+               return 0;
+       return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
+                         &on, sizeof(on));
+}
+
 #ifndef NO_IPV6
 
 static int socksetup(int port, int **socklist_p)
@@ -419,6 +533,11 @@ static int socksetup(int port, int **socklist_p)
                }
 #endif
 
+               if (set_reuse_addr(sockfd)) {
+                       close(sockfd);
+                       continue;
+               }
+
                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
                        close(sockfd);
                        continue;       /* not fatal */
@@ -461,6 +580,11 @@ static int socksetup(int port, int **socklist_p)
        sin.sin_addr.s_addr = htonl(INADDR_ANY);
        sin.sin_port = htons(port);
 
+       if (set_reuse_addr(sockfd)) {
+               close(sockfd);
+               return 0;
+       }
+
        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
                close(sockfd);
                return 0;
@@ -583,6 +707,22 @@ int main(int argc, char **argv)
                        strict_paths = 1;
                        continue;
                }
+               if (!strncmp(arg, "--base-path=", 12)) {
+                       base_path = arg+12;
+                       continue;
+               }
+               if (!strcmp(arg, "--reuseaddr")) {
+                       reuseaddr = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--user-path")) {
+                       user_path = "";
+                       continue;
+               }
+               if (!strncmp(arg, "--user-path=", 12)) {
+                       user_path = arg + 12;
+                       continue;
+               }
                if (!strcmp(arg, "--")) {
                        ok_paths = &argv[i+1];
                        break;