| #include "cache.h" |
| #include "credential.h" |
| #include "unix-socket.h" |
| #include "sigchain.h" |
| |
| static const char *socket_path; |
| |
| static void cleanup_socket(void) |
| { |
| if (socket_path) |
| unlink(socket_path); |
| } |
| |
| static void cleanup_socket_on_signal(int sig) |
| { |
| cleanup_socket(); |
| sigchain_pop(sig); |
| raise(sig); |
| } |
| |
| struct credential_cache_entry { |
| struct credential item; |
| unsigned long expiration; |
| }; |
| static struct credential_cache_entry *entries; |
| static int entries_nr; |
| static int entries_alloc; |
| |
| static void cache_credential(struct credential *c, int timeout) |
| { |
| struct credential_cache_entry *e; |
| |
| ALLOC_GROW(entries, entries_nr + 1, entries_alloc); |
| e = &entries[entries_nr++]; |
| |
| /* take ownership of pointers */ |
| memcpy(&e->item, c, sizeof(*c)); |
| memset(c, 0, sizeof(*c)); |
| e->expiration = time(NULL) + timeout; |
| } |
| |
| static struct credential_cache_entry *lookup_credential(const struct credential *c) |
| { |
| int i; |
| for (i = 0; i < entries_nr; i++) { |
| struct credential *e = &entries[i].item; |
| if (credential_match(c, e)) |
| return &entries[i]; |
| } |
| return NULL; |
| } |
| |
| static void remove_credential(const struct credential *c) |
| { |
| struct credential_cache_entry *e; |
| |
| e = lookup_credential(c); |
| if (e) |
| e->expiration = 0; |
| } |
| |
| static int check_expirations(void) |
| { |
| static unsigned long wait_for_entry_until; |
| int i = 0; |
| unsigned long now = time(NULL); |
| unsigned long next = (unsigned long)-1; |
| |
| /* |
| * Initially give the client 30 seconds to actually contact us |
| * and store a credential before we decide there's no point in |
| * keeping the daemon around. |
| */ |
| if (!wait_for_entry_until) |
| wait_for_entry_until = now + 30; |
| |
| while (i < entries_nr) { |
| if (entries[i].expiration <= now) { |
| entries_nr--; |
| credential_clear(&entries[i].item); |
| if (i != entries_nr) |
| memcpy(&entries[i], &entries[entries_nr], sizeof(*entries)); |
| /* |
| * Stick around 30 seconds in case a new credential |
| * shows up (e.g., because we just removed a failed |
| * one, and we will soon get the correct one). |
| */ |
| wait_for_entry_until = now + 30; |
| } |
| else { |
| if (entries[i].expiration < next) |
| next = entries[i].expiration; |
| i++; |
| } |
| } |
| |
| if (!entries_nr) { |
| if (wait_for_entry_until <= now) |
| return 0; |
| next = wait_for_entry_until; |
| } |
| |
| return next - now; |
| } |
| |
| static int read_request(FILE *fh, struct credential *c, |
| struct strbuf *action, int *timeout) { |
| static struct strbuf item = STRBUF_INIT; |
| const char *p; |
| |
| strbuf_getline(&item, fh, '\n'); |
| if (!skip_prefix(item.buf, "action=", &p)) |
| return error("client sent bogus action line: %s", item.buf); |
| strbuf_addstr(action, p); |
| |
| strbuf_getline(&item, fh, '\n'); |
| if (!skip_prefix(item.buf, "timeout=", &p)) |
| return error("client sent bogus timeout line: %s", item.buf); |
| *timeout = atoi(p); |
| |
| if (credential_read(c, fh) < 0) |
| return -1; |
| return 0; |
| } |
| |
| static void serve_one_client(FILE *in, FILE *out) |
| { |
| struct credential c = CREDENTIAL_INIT; |
| struct strbuf action = STRBUF_INIT; |
| int timeout = -1; |
| |
| if (read_request(in, &c, &action, &timeout) < 0) |
| /* ignore error */ ; |
| else if (!strcmp(action.buf, "get")) { |
| struct credential_cache_entry *e = lookup_credential(&c); |
| if (e) { |
| fprintf(out, "username=%s\n", e->item.username); |
| fprintf(out, "password=%s\n", e->item.password); |
| } |
| } |
| else if (!strcmp(action.buf, "exit")) |
| exit(0); |
| else if (!strcmp(action.buf, "erase")) |
| remove_credential(&c); |
| else if (!strcmp(action.buf, "store")) { |
| if (timeout < 0) |
| warning("cache client didn't specify a timeout"); |
| else if (!c.username || !c.password) |
| warning("cache client gave us a partial credential"); |
| else { |
| remove_credential(&c); |
| cache_credential(&c, timeout); |
| } |
| } |
| else |
| warning("cache client sent unknown action: %s", action.buf); |
| |
| credential_clear(&c); |
| strbuf_release(&action); |
| } |
| |
| static int serve_cache_loop(int fd) |
| { |
| struct pollfd pfd; |
| unsigned long wakeup; |
| |
| wakeup = check_expirations(); |
| if (!wakeup) |
| return 0; |
| |
| pfd.fd = fd; |
| pfd.events = POLLIN; |
| if (poll(&pfd, 1, 1000 * wakeup) < 0) { |
| if (errno != EINTR) |
| die_errno("poll failed"); |
| return 1; |
| } |
| |
| if (pfd.revents & POLLIN) { |
| int client, client2; |
| FILE *in, *out; |
| |
| client = accept(fd, NULL, NULL); |
| if (client < 0) { |
| warning("accept failed: %s", strerror(errno)); |
| return 1; |
| } |
| client2 = dup(client); |
| if (client2 < 0) { |
| warning("dup failed: %s", strerror(errno)); |
| close(client); |
| return 1; |
| } |
| |
| in = xfdopen(client, "r"); |
| out = xfdopen(client2, "w"); |
| serve_one_client(in, out); |
| fclose(in); |
| fclose(out); |
| } |
| return 1; |
| } |
| |
| static void serve_cache(const char *socket_path) |
| { |
| int fd; |
| |
| fd = unix_stream_listen(socket_path); |
| if (fd < 0) |
| die_errno("unable to bind to '%s'", socket_path); |
| |
| printf("ok\n"); |
| fclose(stdout); |
| |
| while (serve_cache_loop(fd)) |
| ; /* nothing */ |
| |
| close(fd); |
| unlink(socket_path); |
| } |
| |
| static const char permissions_advice[] = |
| "The permissions on your socket directory are too loose; other\n" |
| "users may be able to read your cached credentials. Consider running:\n" |
| "\n" |
| " chmod 0700 %s"; |
| static void check_socket_directory(const char *path) |
| { |
| struct stat st; |
| char *path_copy = xstrdup(path); |
| char *dir = dirname(path_copy); |
| |
| if (!stat(dir, &st)) { |
| if (st.st_mode & 077) |
| die(permissions_advice, dir); |
| free(path_copy); |
| return; |
| } |
| |
| /* |
| * We must be sure to create the directory with the correct mode, |
| * not just chmod it after the fact; otherwise, there is a race |
| * condition in which somebody can chdir to it, sleep, then try to open |
| * our protected socket. |
| */ |
| if (safe_create_leading_directories_const(dir) < 0) |
| die_errno("unable to create directories for '%s'", dir); |
| if (mkdir(dir, 0700) < 0) |
| die_errno("unable to mkdir '%s'", dir); |
| free(path_copy); |
| } |
| |
| int main(int argc, const char **argv) |
| { |
| socket_path = argv[1]; |
| |
| if (!socket_path) |
| die("usage: git-credential-cache--daemon <socket_path>"); |
| check_socket_directory(socket_path); |
| |
| atexit(cleanup_socket); |
| sigchain_push_common(cleanup_socket_on_signal); |
| |
| serve_cache(socket_path); |
| |
| return 0; |
| } |