diff options
Diffstat (limited to 'daemon.c')
-rw-r--r-- | daemon.c | 473 |
1 files changed, 178 insertions, 295 deletions
@@ -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); } @@ -827,7 +716,7 @@ static int socksetup(char *listen_addr, int listen_port, int **socklist_p) gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0); if (gai) - die("getaddrinfo() failed: %s\n", gai_strerror(gai)); + die("getaddrinfo() failed: %s", gai_strerror(gai)); for (ai = ai0; ai; ai = ai->ai_next) { int sockfd; @@ -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 +937,14 @@ 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); + git_extract_argv0_path(argv[0]); 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 +980,12 @@ 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 +1059,11 @@ 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 +1095,18 @@ 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 +1114,10 @@ int main(int argc, char **argv) return execute(peer); } - if (detach) + if (detach) { daemonize(); + loginfo("Ready to rumble"); + } else sanitize_stdfds(); |