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-rw-r--r--daemon.c471
1 files changed, 176 insertions, 295 deletions
diff --git a/daemon.c b/daemon.c
index 8dcde73..60bf6c7 100644
--- a/daemon.c
+++ b/daemon.c
@@ -1,7 +1,6 @@
#include "cache.h"
#include "pkt-line.h"
#include "exec_cmd.h"
-#include "interpolate.h"
#include <syslog.h>
@@ -16,12 +15,11 @@
static int log_syslog;
static int verbose;
static int reuseaddr;
-static int child_handler_pipe[2];
static const char daemon_usage[] =
"git daemon [--verbose] [--syslog] [--export-all]\n"
-" [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
-" [--base-path=path] [--base-path-relaxed]\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"
@@ -55,61 +53,26 @@ 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 char *hostname;
+static char *canon_hostname;
+static char *ip_address;
+static char *tcp_port;
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) {
+ char buf[1024];
+ vsnprintf(buf, sizeof(buf), err, params);
syslog(priority, "%s", buf);
- return;
+ } else {
+ /*
+ * Since stderr is set to linebuffered mode, the
+ * logging of different processes will not overlap
+ */
+ fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
+ vfprintf(stderr, err, params);
+ fputc('\n', stderr);
}
-
- /* 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_in_full(2, buf, buflen);
}
static void logerror(const char *err, ...)
@@ -183,15 +146,14 @@ static int avoid_alias(char *p)
}
}
-static char *path_ok(struct interp *itable)
+static char *path_ok(char *directory)
{
static char rpath[PATH_MAX];
static char interp_path[PATH_MAX];
- int retried_path = 0;
char *path;
char *dir;
- dir = itable[INTERP_SLOT_DIR].value;
+ dir = directory;
if (avoid_alias(dir)) {
logerror("'%s': aliased", dir);
@@ -221,14 +183,27 @@ static char *path_ok(struct interp *itable)
}
}
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 }
+ };
+
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));
+ strbuf_expand(&expanded_path, interpolated_path,
+ strbuf_expand_dict_cb, &dict);
+ strlcpy(interp_path, expanded_path.buf, PATH_MAX);
+ strbuf_release(&expanded_path);
loginfo("Interpolated dir '%s'", interp_path);
dir = interp_path;
@@ -243,22 +218,15 @@ static char *path_ok(struct interp *itable)
dir = rpath;
}
- do {
- path = enter_repo(dir, strict_paths);
- if (path)
- break;
-
+ path = enter_repo(dir, strict_paths);
+ if (!path && base_path && base_path_relaxed) {
/*
* if we fail and base_path_relaxed is enabled, try without
* prefixing the base path
*/
- if (base_path && base_path_relaxed && !retried_path) {
- dir = itable[INTERP_SLOT_DIR].value;
- retried_path = 1;
- continue;
- }
- break;
- } while (1);
+ dir = directory;
+ path = enter_repo(dir, strict_paths);
+ }
if (!path) {
logerror("'%s': unable to chdir or not a git archive", dir);
@@ -319,14 +287,12 @@ static int git_daemon_config(const char *var, const char *value, void *cb)
return 0;
}
-static int run_service(struct interp *itable, struct daemon_service *service)
+static int run_service(char *dir, struct daemon_service *service)
{
const char *path;
int enabled = service->enabled;
- loginfo("Request %s for '%s'",
- service->name,
- itable[INTERP_SLOT_DIR].value);
+ loginfo("Request %s for '%s'", service->name, dir);
if (!enabled && !service->overridable) {
logerror("'%s': service not enabled.", service->name);
@@ -334,7 +300,7 @@ static int run_service(struct interp *itable, struct daemon_service *service)
return -1;
}
- if (!(path = path_ok(itable)))
+ if (!(path = path_ok(dir)))
return -1;
/*
@@ -431,11 +397,18 @@ static void make_service_overridable(const char *name, int ena)
die("No such service %s", name);
}
+static char *xstrdup_tolower(const char *str)
+{
+ char *p, *dup = xstrdup(str);
+ for (p = dup; *p; p++)
+ *p = tolower(*p);
+ return dup;
+}
+
/*
* 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)
+static void parse_extra_args(char *extra_args, int buflen)
{
char *val;
int vallen;
@@ -453,35 +426,23 @@ static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
if (port) {
*port = 0;
port++;
- interp_set_entry(table, INTERP_SLOT_PORT, port);
+ free(tcp_port);
+ tcp_port = xstrdup(port);
}
- interp_set_entry(table, INTERP_SLOT_HOST, host);
+ free(hostname);
+ hostname = xstrdup_tolower(host);
}
/* On to the next one */
extra_args = val + vallen;
}
}
-}
-
-static 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.
*/
+ if (hostname) {
#ifndef NO_IPV6
- {
struct addrinfo hints;
struct addrinfo *ai, *ai0;
int gai;
@@ -490,30 +451,28 @@ static void fill_in_extra_table_entries(struct interp *itable)
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
- gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
+ gai = getaddrinfo(hostname, 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);
+ free(canon_hostname);
+ canon_hostname = xstrdup(ai->ai_canonname);
+ free(ip_address);
+ ip_address = xstrdup(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);
+ hent = gethostbyname(hostname);
ap = hent->h_addr_list;
memset(&sa, 0, sizeof sa);
@@ -524,10 +483,12 @@ static void fill_in_extra_table_entries(struct interp *itable)
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);
- }
+ free(canon_hostname);
+ canon_hostname = xstrdup(hent->h_name);
+ free(ip_address);
+ ip_address = xstrdup(addrbuf);
#endif
+ }
}
@@ -557,6 +518,10 @@ static int execute(struct sockaddr *addr)
#endif
}
loginfo("Connection from %s:%d", addrbuf, port);
+ setenv("REMOTE_ADDR", addrbuf, 1);
+ }
+ else {
+ unsetenv("REMOTE_ADDR");
}
alarm(init_timeout ? init_timeout : timeout);
@@ -573,16 +538,14 @@ static int execute(struct sockaddr *addr)
pktlen--;
}
- /*
- * 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, "%");
+ free(hostname);
+ free(canon_hostname);
+ free(ip_address);
+ free(tcp_port);
+ hostname = canon_hostname = ip_address = tcp_port = NULL;
- if (len != pktlen) {
- parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
- fill_in_extra_table_entries(interp_table);
- }
+ if (len != pktlen)
+ parse_extra_args(line + len + 1, pktlen - len - 1);
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
struct daemon_service *s = &(daemon_service[i]);
@@ -594,9 +557,7 @@ static int execute(struct sockaddr *addr)
* 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);
+ return run_service(line + namelen + 5, s);
}
}
@@ -604,169 +565,107 @@ static int execute(struct sockaddr *addr)
return -1;
}
+static int max_connections = 32;
-/*
- * 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;
-static pid_t dead_child[MAX_CHILDREN];
-
-/* These are updated by the main loop */
-static unsigned int children_spawned;
-static unsigned int children_deleted;
+static unsigned int live_children;
static struct child {
+ struct child *next;
pid_t pid;
- int addrlen;
struct sockaddr_storage address;
-} live_child[MAX_CHILDREN];
+} *firstborn;
-static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
+static void add_child(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);
+ 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->address, addr, addrlen);
+ for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
+ if (!memcmp(&(*cradle)->address, &newborn->address,
+ sizeof(newborn->address)))
+ break;
+ newborn->next = *cradle;
+ *cradle = newborn;
}
-/*
- * 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)
+static void remove_child(pid_t pid)
{
- struct child n;
+ struct child **cradle, *blanket;
- 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;
- }
+ 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".
*
- * 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.
+ * We kill the newest connection from a duplicate IP.
*/
-static void kill_some_children(int signo, unsigned start, unsigned stop)
+static void kill_some_child(void)
{
- 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_dead_children(void)
-{
- unsigned spawned, reaped, deleted;
-
- spawned = children_spawned;
- reaped = children_reaped;
- deleted = children_deleted;
+ const struct child *blanket, *next;
- while (deleted < reaped) {
- pid_t pid = dead_child[deleted % MAX_CHILDREN];
- const char *dead = pid < 0 ? " (with error)" : "";
-
- if (pid < 0)
- pid = -pid;
+ if (!(blanket = firstborn))
+ return;
- /* XXX: Custom logging, since we don't wanna getpid() */
- if (verbose) {
- if (log_syslog)
- syslog(LOG_INFO, "[%d] Disconnected%s",
- pid, dead);
- else
- fprintf(stderr, "[%d] Disconnected%s\n",
- pid, dead);
+ for (; (next = blanket->next); blanket = next)
+ if (!memcmp(&blanket->address, &next->address,
+ sizeof(next->address))) {
+ kill(blanket->pid, SIGTERM);
+ break;
}
- remove_child(pid, deleted, spawned);
- deleted++;
- }
- children_deleted = deleted;
}
-static void check_max_connections(void)
+static void check_dead_children(void)
{
- for (;;) {
- int active;
- unsigned spawned, deleted;
-
- check_dead_children();
-
- spawned = children_spawned;
- deleted = children_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;
+ int status;
+ pid_t pid;
- /* If the SIGTERM thing isn't helping use SIGKILL */
- kill_some_children(SIGKILL, deleted, spawned);
- sleep(1);
+ 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);
}
}
static void handle(int incoming, struct sockaddr *addr, int addrlen)
{
- pid_t pid = fork();
+ pid_t pid;
- if (pid) {
- unsigned idx;
+ if (max_connections && live_children >= max_connections) {
+ kill_some_child();
+ sleep(1); /* give it some time to die */
+ check_dead_children();
+ if (live_children >= max_connections) {
+ close(incoming);
+ logerror("Too many children, dropping connection");
+ return;
+ }
+ }
+ if ((pid = fork())) {
close(incoming);
- if (pid < 0)
+ if (pid < 0) {
+ logerror("Couldn't fork %s", strerror(errno));
return;
+ }
- idx = children_spawned % MAX_CHILDREN;
- children_spawned++;
- add_child(idx, pid, addr, addrlen);
-
- check_max_connections();
+ add_child(pid, addr, addrlen);
return;
}
@@ -779,21 +678,11 @@ static void handle(int incoming, struct sockaddr *addr, int addrlen)
static void child_handler(int signo)
{
- for (;;) {
- int status;
- pid_t pid = waitpid(-1, &status, WNOHANG);
-
- if (pid > 0) {
- unsigned reaped = children_reaped;
- if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
- pid = -pid;
- dead_child[reaped % MAX_CHILDREN] = pid;
- children_reaped = reaped + 1;
- write(child_handler_pipe[1], &status, 1);
- continue;
- }
- break;
- }
+ /*
+ * Otherwise empty handler because systemcalls will get interrupted
+ * upon signal receipt
+ * SysV needs the handler to be rearmed
+ */
signal(SIGCHLD, child_handler);
}
@@ -836,7 +725,7 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
if (sockfd < 0)
continue;
if (sockfd >= FD_SETSIZE) {
- error("too large socket descriptor.");
+ logerror("Socket descriptor too large");
close(sockfd);
continue;
}
@@ -936,35 +825,28 @@ static int service_loop(int socknum, int *socklist)
struct pollfd *pfd;
int i;
- if (pipe(child_handler_pipe) < 0)
- die ("Could not set up pipe for child handler");
-
- pfd = xcalloc(socknum + 1, sizeof(struct pollfd));
+ pfd = xcalloc(socknum, sizeof(struct pollfd));
for (i = 0; i < socknum; i++) {
pfd[i].fd = socklist[i];
pfd[i].events = POLLIN;
}
- pfd[socknum].fd = child_handler_pipe[0];
- pfd[socknum].events = POLLIN;
signal(SIGCHLD, child_handler);
for (;;) {
int i;
- if (poll(pfd, socknum + 1, -1) < 0) {
+ check_dead_children();
+
+ if (poll(pfd, socknum, -1) < 0) {
if (errno != EINTR) {
- error("poll failed, resuming: %s",
+ logerror("Poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
- if (pfd[socknum].revents & POLLIN) {
- read(child_handler_pipe[0], &i, 1);
- check_dead_children();
- }
for (i = 0; i < socknum; i++) {
if (pfd[i].revents & POLLIN) {
@@ -1022,7 +904,7 @@ static void store_pid(const char *path)
FILE *f = fopen(path, "w");
if (!f)
die("cannot open pid file %s: %s", path, strerror(errno));
- if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
+ if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
die("failed to write pid file %s: %s", path, strerror(errno));
}
@@ -1055,21 +937,12 @@ int main(int argc, char **argv)
gid_t gid = 0;
int i;
- /* Without this we cannot rely on waitpid() to tell
- * what happened to our children.
- */
- signal(SIGCHLD, SIG_DFL);
-
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (!prefixcmp(arg, "--listen=")) {
- char *p = arg + 9;
- char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
- while (*p)
- *ph++ = tolower(*p++);
- *ph = 0;
- continue;
+ listen_addr = xstrdup_tolower(arg + 9);
+ continue;
}
if (!prefixcmp(arg, "--port=")) {
char *end;
@@ -1105,6 +978,12 @@ int main(int argc, char **argv)
init_timeout = atoi(arg+15);
continue;
}
+ if (!prefixcmp(arg, "--max-connections=")) {
+ max_connections = atoi(arg+18);
+ if (max_connections < 0)
+ max_connections = 0; /* unlimited */
+ continue;
+ }
if (!strcmp(arg, "--strict-paths")) {
strict_paths = 1;
continue;
@@ -1178,9 +1057,11 @@ int main(int argc, char **argv)
}
if (log_syslog) {
- openlog("git-daemon", 0, LOG_DAEMON);
+ openlog("git-daemon", LOG_PID, LOG_DAEMON);
set_die_routine(daemon_die);
- }
+ } else
+ /* avoid splitting a message in the middle */
+ setvbuf(stderr, NULL, _IOLBF, 0);
if (inetd_mode && (group_name || user_name))
die("--user and --group are incompatible with --inetd");
@@ -1212,20 +1093,18 @@ int main(int argc, char **argv)
if (strict_paths && (!ok_paths || !*ok_paths))
die("option --strict-paths requires a whitelist");
- if (base_path) {
- struct stat st;
-
- if (stat(base_path, &st) || !S_ISDIR(st.st_mode))
- die("base-path '%s' does not exist or "
- "is not a directory", base_path);
- }
+ if (base_path && !is_directory(base_path))
+ die("base-path '%s' does not exist or is not a directory",
+ base_path);
if (inetd_mode) {
struct sockaddr_storage ss;
struct sockaddr *peer = (struct sockaddr *)&ss;
socklen_t slen = sizeof(ss);
- freopen("/dev/null", "w", stderr);
+ if (!freopen("/dev/null", "w", stderr))
+ die("failed to redirect stderr to /dev/null: %s",
+ strerror(errno));
if (getpeername(0, peer, &slen))
peer = NULL;
@@ -1233,8 +1112,10 @@ int main(int argc, char **argv)
return execute(peer);
}
- if (detach)
+ if (detach) {
daemonize();
+ loginfo("Ready to rumble");
+ }
else
sanitize_stdfds();