#include "cache.h"
#include "pkt-line.h"
+#include <signal.h>
+#include <sys/wait.h>
#include <sys/socket.h>
+#include <sys/time.h>
+#include <netdb.h>
#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <syslog.h>
-static const char daemon_usage[] = "git-daemon [--inetd | --port=n]";
+static int log_syslog;
+static int verbose;
-static int upload(char *dir, int dirlen)
+static const char daemon_usage[] = "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all] [directory...]";
+
+/* List of acceptable pathname prefixes */
+static char **ok_paths = NULL;
+
+/* If this is set, git-daemon-export-ok is not required */
+static int export_all_trees = 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
+ * of several processes do not get intermingled. */
+ char buf[1024];
+ int buflen;
+ int maxlen, msglen;
+
+ /* sizeof(buf) should be big enough for "[pid] \n" */
+ buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
+
+ maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
+ msglen = vsnprintf(buf + buflen, maxlen, err, params);
+
+ if (log_syslog) {
+ syslog(priority, "%s", buf);
+ return;
+ }
+
+ /* maxlen counted our own LF but also counts space given to
+ * vsnprintf for the terminating NUL. We want to make sure that
+ * we have space for our own LF and NUL after the "meat" of the
+ * message, so truncate it at maxlen - 1.
+ */
+ if (msglen > maxlen - 1)
+ msglen = maxlen - 1;
+ else if (msglen < 0)
+ msglen = 0; /* Protect against weird return values. */
+ buflen += msglen;
+
+ buf[buflen++] = '\n';
+ buf[buflen] = '\0';
+
+ write(2, buf, buflen);
+}
+
+static void logerror(const char *err, ...)
+{
+ va_list params;
+ va_start(params, err);
+ logreport(LOG_ERR, err, params);
+ va_end(params);
+}
+
+static void loginfo(const char *err, ...)
{
- if (chdir(dir) < 0)
+ va_list params;
+ if (!verbose)
+ return;
+ va_start(params, err);
+ logreport(LOG_INFO, err, params);
+ va_end(params);
+}
+
+static int path_ok(const char *dir)
+{
+ const char *p = dir;
+ char **pp;
+ int sl, ndot;
+
+ /* The pathname here should be an absolute path. */
+ if ( *p++ != '/' )
+ return 0;
+
+ sl = 1; ndot = 0;
+
+ for (;;) {
+ if ( *p == '.' ) {
+ ndot++;
+ } else if ( *p == '\0' ) {
+ /* Reject "." and ".." at the end of the path */
+ if ( sl && ndot > 0 && ndot < 3 )
+ return 0;
+
+ /* Otherwise OK */
+ break;
+ } else if ( *p == '/' ) {
+ /* Refuse "", "." or ".." */
+ if ( sl && ndot < 3 )
+ return 0;
+ sl = 1;
+ ndot = 0;
+ } else {
+ sl = ndot = 0;
+ }
+ p++;
+ }
+
+ if ( ok_paths && *ok_paths ) {
+ int ok = 0;
+ int dirlen = strlen(dir);
+
+ for ( pp = ok_paths ; *pp ; pp++ ) {
+ int len = strlen(*pp);
+ if ( len <= dirlen &&
+ !strncmp(*pp, dir, len) &&
+ (dir[len] == '/' || dir[len] == '\0') ) {
+ ok = 1;
+ break;
+ }
+ }
+
+ if ( !ok )
+ return 0; /* Path not in whitelist */
+ }
+
+ return 1; /* Path acceptable */
+}
+
+static int set_dir(const char *dir)
+{
+ if (!path_ok(dir)) {
+ errno = EACCES;
return -1;
- chdir(".git");
+ }
+ if ( chdir(dir) )
+ return -1;
+
/*
* Security on the cheap.
*
* a "git-daemon-export-ok" flag that says that the other side
* is ok with us doing this.
*/
- if (access("git-daemon-export-ok", F_OK) ||
- access("objects/00", X_OK) ||
- access("HEAD", R_OK))
+ if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
+ errno = EACCES;
+ return -1;
+ }
+
+ if (access("objects/", X_OK) || access("HEAD", R_OK)) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* If all this passed, we're OK */
+ return 0;
+}
+
+static int upload(char *dir)
+{
+ /* Try paths in this order */
+ static const char *paths[] = { "%s", "%s/.git", "%s.git", "%s.git/.git", NULL };
+ const char **pp;
+ /* Enough for the longest path above including final null */
+ int buflen = strlen(dir)+10;
+ char *dirbuf = xmalloc(buflen);
+
+ loginfo("Request for '%s'", dir);
+
+ for ( pp = paths ; *pp ; pp++ ) {
+ snprintf(dirbuf, buflen, *pp, dir);
+ if ( !set_dir(dirbuf) )
+ break;
+ }
+
+ if ( !*pp ) {
+ logerror("Cannot set directory '%s': %s", dir, strerror(errno));
return -1;
+ }
+
+ /*
+ * We'll ignore SIGTERM from now on, we have a
+ * good client.
+ */
+ signal(SIGTERM, SIG_IGN);
/* git-upload-pack only ever reads stuff, so this is safe */
execlp("git-upload-pack", "git-upload-pack", ".", NULL);
line[--len] = 0;
if (!strncmp("git-upload-pack /", line, 17))
- return upload(line + 16, len - 16);
+ return upload(line+16);
- fprintf(stderr, "got bad connection '%s'\n", line);
+ logerror("Protocol error: '%s'", line);
return -1;
}
-static void handle(int incoming, struct sockaddr_in *addr, int addrlen)
+
+/*
+ * We count spawned/reaped separately, just to avoid any
+ * races when updating them from signals. The SIGCHLD handler
+ * will only update children_reaped, and the fork logic will
+ * only update children_spawned.
+ *
+ * MAX_CHILDREN should be a power-of-two to make the modulus
+ * operation cheap. It should also be at least twice
+ * the maximum number of connections we will ever allow.
+ */
+#define MAX_CHILDREN 128
+
+static int max_connections = 25;
+
+/* These are updated by the signal handler */
+static volatile unsigned int children_reaped = 0;
+static pid_t dead_child[MAX_CHILDREN];
+
+/* These are updated by the main loop */
+static unsigned int children_spawned = 0;
+static unsigned int children_deleted = 0;
+
+static struct child {
+ pid_t pid;
+ int addrlen;
+ struct sockaddr_storage address;
+} live_child[MAX_CHILDREN];
+
+static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
+{
+ live_child[idx].pid = pid;
+ live_child[idx].addrlen = addrlen;
+ memcpy(&live_child[idx].address, addr, addrlen);
+}
+
+/*
+ * Walk from "deleted" to "spawned", and remove child "pid".
+ *
+ * We move everything up by one, since the new "deleted" will
+ * be one higher.
+ */
+static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
{
- if (fork()) {
+ struct child n;
+
+ deleted %= MAX_CHILDREN;
+ spawned %= MAX_CHILDREN;
+ if (live_child[deleted].pid == pid) {
+ live_child[deleted].pid = -1;
+ return;
+ }
+ n = live_child[deleted];
+ for (;;) {
+ struct child m;
+ deleted = (deleted + 1) % MAX_CHILDREN;
+ if (deleted == spawned)
+ die("could not find dead child %d\n", pid);
+ m = live_child[deleted];
+ live_child[deleted] = n;
+ if (m.pid == pid)
+ return;
+ n = m;
+ }
+}
+
+/*
+ * This gets called if the number of connections grows
+ * past "max_connections".
+ *
+ * We _should_ start off by searching for connections
+ * from the same IP, and if there is some address wth
+ * multiple connections, we should kill that first.
+ *
+ * As it is, we just "randomly" kill 25% of the connections,
+ * and our pseudo-random generator sucks too. I have no
+ * shame.
+ *
+ * Really, this is just a place-holder for a _real_ algorithm.
+ */
+static void kill_some_children(int signo, unsigned start, unsigned stop)
+{
+ start %= MAX_CHILDREN;
+ stop %= MAX_CHILDREN;
+ while (start != stop) {
+ if (!(start & 3))
+ kill(live_child[start].pid, signo);
+ start = (start + 1) % MAX_CHILDREN;
+ }
+}
+
+static void check_max_connections(void)
+{
+ for (;;) {
+ int active;
+ unsigned spawned, reaped, deleted;
+
+ spawned = children_spawned;
+ reaped = children_reaped;
+ deleted = children_deleted;
+
+ while (deleted < reaped) {
+ pid_t pid = dead_child[deleted % MAX_CHILDREN];
+ remove_child(pid, deleted, spawned);
+ deleted++;
+ }
+ children_deleted = deleted;
+
+ active = spawned - deleted;
+ if (active <= max_connections)
+ break;
+
+ /* Kill some unstarted connections with SIGTERM */
+ kill_some_children(SIGTERM, deleted, spawned);
+ if (active <= max_connections << 1)
+ break;
+
+ /* If the SIGTERM thing isn't helping use SIGKILL */
+ kill_some_children(SIGKILL, deleted, spawned);
+ sleep(1);
+ }
+}
+
+static void handle(int incoming, struct sockaddr *addr, int addrlen)
+{
+ pid_t pid = fork();
+ char addrbuf[256] = "";
+ int port = -1;
+
+ if (pid) {
+ unsigned idx;
+
close(incoming);
+ if (pid < 0)
+ return;
+
+ idx = children_spawned % MAX_CHILDREN;
+ children_spawned++;
+ add_child(idx, pid, addr, addrlen);
+
+ check_max_connections();
return;
}
dup2(incoming, 0);
dup2(incoming, 1);
close(incoming);
+
+ if (addr->sa_family == AF_INET) {
+ struct sockaddr_in *sin_addr = (void *) addr;
+ inet_ntop(AF_INET, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
+ port = sin_addr->sin_port;
+
+ } else if (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 = sin6_addr->sin6_port;
+ }
+ loginfo("Connection from %s:%d", addrbuf, port);
+
exit(execute());
}
+static void child_handler(int signo)
+{
+ for (;;) {
+ int status;
+ pid_t pid = waitpid(-1, &status, WNOHANG);
+
+ if (pid > 0) {
+ unsigned reaped = children_reaped;
+ dead_child[reaped % MAX_CHILDREN] = pid;
+ children_reaped = reaped + 1;
+ /* XXX: Custom logging, since we don't wanna getpid() */
+ if (verbose) {
+ char *dead = "";
+ if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
+ dead = " (with error)";
+ if (log_syslog)
+ syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
+ else
+ fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
+ }
+ continue;
+ }
+ break;
+ }
+}
+
static int serve(int port)
{
- int sockfd;
- struct sockaddr_in addr;
-
- sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_IP);
- if (sockfd < 0)
- die("unable to open socket (%s)", strerror(errno));
- memset(&addr, 0, sizeof(addr));
- addr.sin_port = htons(port);
- addr.sin_family = AF_INET;
- if (bind(sockfd, (void *)&addr, sizeof(addr)) < 0)
- die("unable to bind to port %d (%s)", port, strerror(errno));
- if (listen(sockfd, 5) < 0)
- die("unable to listen to port %d (%s)", port, strerror(errno));
+ struct addrinfo hints, *ai0, *ai;
+ int gai;
+ int socknum = 0, *socklist = NULL;
+ int maxfd = -1;
+ fd_set fds_init, fds;
+ char pbuf[NI_MAXSERV];
+
+ signal(SIGCHLD, child_handler);
+
+ sprintf(pbuf, "%d", 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);
+ if (gai)
+ die("getaddrinfo() failed: %s\n", gai_strerror(gai));
+
+ FD_ZERO(&fds_init);
+
+ 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)
+ continue;
+ if (sockfd >= FD_SETSIZE) {
+ error("too large socket descriptor.");
+ close(sockfd);
+ continue;
+ }
+
+#ifdef IPV6_V6ONLY
+ if (ai->ai_family == AF_INET6) {
+ int on = 1;
+ setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
+ &on, sizeof(on));
+ /* Note: error is not fatal */
+ }
+#endif
+
+ if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
+ close(sockfd);
+ continue; /* not fatal */
+ }
+ if (listen(sockfd, 5) < 0) {
+ close(sockfd);
+ continue; /* not fatal */
+ }
+
+ newlist = realloc(socklist, sizeof(int) * (socknum + 1));
+ if (!newlist)
+ die("memory allocation failed: %s", strerror(errno));
+
+ socklist = newlist;
+ socklist[socknum++] = sockfd;
+
+ FD_SET(sockfd, &fds_init);
+ if (maxfd < sockfd)
+ maxfd = sockfd;
+ }
+
+ freeaddrinfo(ai0);
+
+ if (socknum == 0)
+ die("unable to allocate any listen sockets on port %u", port);
for (;;) {
- struct sockaddr_in in;
- socklen_t addrlen = sizeof(in);
- int incoming = accept(sockfd, (void *)&in, &addrlen);
-
- if (incoming < 0) {
- switch (errno) {
- case EAGAIN:
- case EINTR:
- case ECONNABORTED:
- continue;
- default:
- die("accept returned %s", strerror(errno));
+ int i;
+ fds = fds_init;
+
+ if (select(maxfd + 1, &fds, NULL, NULL, NULL) < 0) {
+ if (errno != EINTR) {
+ error("select failed, resuming: %s",
+ strerror(errno));
+ sleep(1);
+ }
+ continue;
+ }
+
+ for (i = 0; i < socknum; i++) {
+ int sockfd = socklist[i];
+
+ if (FD_ISSET(sockfd, &fds)) {
+ struct sockaddr_storage ss;
+ int sslen = sizeof(ss);
+ int incoming = accept(sockfd, (struct sockaddr *)&ss, &sslen);
+ if (incoming < 0) {
+ switch (errno) {
+ case EAGAIN:
+ case EINTR:
+ case ECONNABORTED:
+ continue;
+ default:
+ die("accept returned %s", strerror(errno));
+ }
+ }
+ handle(incoming, (struct sockaddr *)&ss, sslen);
}
}
- handle(incoming, &in, addrlen);
}
}
continue;
}
}
-
if (!strcmp(arg, "--inetd")) {
inetd_mode = 1;
continue;
}
+ if (!strcmp(arg, "--verbose")) {
+ verbose = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--syslog")) {
+ log_syslog = 1;
+ openlog("git-daemon", 0, LOG_DAEMON);
+ continue;
+ }
+ if (!strcmp(arg, "--export-all")) {
+ export_all_trees = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--")) {
+ ok_paths = &argv[i+1];
+ break;
+ } else if (arg[0] != '-') {
+ ok_paths = &argv[i];
+ break;
+ }
usage(daemon_usage);
}
- if (inetd_mode)
+ if (inetd_mode) {
+ fclose(stderr); //FIXME: workaround
return execute();
+ }
return serve(port);
}
projects / git.git / blobdiff