X-Git-Url: http://www.project-moonshot.org/gitweb/?p=trust_router.git;a=blobdiff_plain;f=tid%2Ftids.c;h=f6da08d9ac16724486bc2b398d3917377c04ccf1;hp=2e5dbea97abf69126f6d4e994e521b89adf8281d;hb=298aea2c08823da7e05747a072dffbcd485491c8;hpb=f55d5503336233c90fb84aec15c2f0a18116831e diff --git a/tid/tids.c b/tid/tids.c index 2e5dbea..f6da08d 100644 --- a/tid/tids.c +++ b/tid/tids.c @@ -49,6 +49,7 @@ #include #include #include +#include /** * Create a response with minimal fields filled in @@ -80,6 +81,12 @@ static TID_RESP *tids_create_response(TALLOC_CTX *mem_ctx, TID_REQ *req) goto cleanup; } } + if (req->request_id) { + if (NULL == (resp->request_id = tr_dup_name(req->request_id))) { + tr_crit("tids_create_response: Error allocating fields in response."); + goto cleanup; + } + } success=1; @@ -310,9 +317,26 @@ cleanup: return resp_msg; } +static int tids_destructor(void *object) +{ + TIDS_INSTANCE *tids = talloc_get_type_abort(object, TIDS_INSTANCE); + if (tids->pids) + g_array_unref(tids->pids); + return 0; +} + TIDS_INSTANCE *tids_new(TALLOC_CTX *mem_ctx) { - return talloc_zero(mem_ctx, TIDS_INSTANCE); + TIDS_INSTANCE *tids = talloc_zero(mem_ctx, TIDS_INSTANCE); + if (tids) { + tids->pids = g_array_new(FALSE, FALSE, sizeof(struct tid_process)); + if (tids->pids == NULL) { + talloc_free(tids); + return NULL; + } + talloc_set_destructor((void *)tids, tids_destructor); + } + return tids; } /** @@ -323,8 +347,9 @@ TIDS_INSTANCE *tids_new(TALLOC_CTX *mem_ctx) */ TIDS_INSTANCE *tids_create(void) { - return talloc_zero(NULL, TIDS_INSTANCE); + return tids_new(NULL); } + /* Get a listener for tids requests, returns its socket fd. Accept * connections with tids_accept() */ nfds_t tids_get_listener(TIDS_INSTANCE *tids, @@ -373,16 +398,81 @@ nfds_t tids_get_listener(TIDS_INSTANCE *tids, return (int)n_fd; } +/* Strings used to report results from the handler process. The + * TIDS_MAX_MESSAGE_LEN must be longer than the longest message, including + * null termination (i.e., strlen() + 1) */ +#define TIDS_MAX_MESSAGE_LEN (10) +#define TIDS_SUCCESS_MESSAGE "OK" +#define TIDS_ERROR_MESSAGE "ERR" + +/** + * Process to handle an incoming TIDS request + * + * This should be run in the child process after a fork(). Handles + * the request, writes the result to result_fd, and terminates. + * Never returns to the caller. + * + * @param tids TID server instance + * @param conn_fd file descriptor for the incoming connection + * @param result_fd writable file descriptor for the result, or 0 to disable reporting + */ +static void tids_handle_proc(TIDS_INSTANCE *tids, int conn_fd, int result_fd) +{ + const char *response_message = NULL; + struct rlimit rlim; /* for disabling core dump */ + + switch(tr_gss_handle_connection(conn_fd, + "trustidentity", tids->hostname, /* acceptor name */ + tids->auth_handler, tids->cookie, /* auth callback and cookie */ + tids_req_cb, tids /* req callback and cookie */ + )) { + case TR_GSS_SUCCESS: + response_message = TIDS_SUCCESS_MESSAGE; + break; + + case TR_GSS_ERROR: + default: + response_message = TIDS_ERROR_MESSAGE; + break; + } + + if (0 != result_fd) { + /* write strlen + 1 to include the null termination */ + if (write(result_fd, response_message, strlen(response_message) + 1) < 0) + tr_err("tids_accept: child process unable to write to pipe"); + } + + close(result_fd); + close(conn_fd); + + /* This ought to be an exit(0), but log4shib does not play well with fork() due to + * threading issues. To ensure we do not get stuck in the exit handler, we will + * abort. First disable core dump for this subprocess (the main process will still + * dump core if the environment allows). */ + rlim.rlim_cur = 0; /* max core size of 0 */ + rlim.rlim_max = 0; /* prevent the core size limit from being raised later */ + setrlimit(RLIMIT_CORE, &rlim); + abort(); /* exit hard */ +} + /* Accept and process a connection on a port opened with tids_get_listener() */ int tids_accept(TIDS_INSTANCE *tids, int listen) { int conn=-1; int pid=-1; + int pipe_fd[2]; + struct tid_process tp = {0}; + + if (0 > (conn = tr_sock_accept(listen))) { + tr_err("tids_accept: Error accepting connection"); + return 1; + } - if (0 > (conn = accept(listen, NULL, NULL))) { - perror("Error from TIDS Server accept()"); + if (0 > pipe(pipe_fd)) { + perror("Error on pipe()"); return 1; } + /* pipe_fd[0] is for reading, pipe_fd[1] is for writing */ if (0 > (pid = fork())) { perror("Error on fork()"); @@ -390,24 +480,99 @@ int tids_accept(TIDS_INSTANCE *tids, int listen) } if (pid == 0) { - close(listen); - tr_gss_handle_connection(conn, - "trustidentity", tids->hostname, /* acceptor name */ - tids->auth_handler, tids->cookie, /* auth callback and cookie */ - tids_req_cb, tids /* req callback and cookie */ - ); - close(conn); - exit(0); /* exit to kill forked child process */ - } else { - close(conn); + /* Only the child process gets here */ + close(pipe_fd[0]); /* close the read end of the pipe, the child only writes */ + close(listen); /* close the child process's handle on the listen port */ + + tids_handle_proc(tids, conn, pipe_fd[1]); /* never returns */ } - /* clean up any processes that have completed (TBD: move to main loop?) */ - while (waitpid(-1, 0, WNOHANG) > 0); + /* Only the parent process gets here */ + close(pipe_fd[1]); /* close the write end of the pipe, the parent only listens */ + close(conn); /* connection belongs to the child, so close parent's handle */ + + /* remember the PID of our child process */ + tr_info("tids_accept: Spawned TID process %d to handle incoming connection.", pid); + tp.pid = pid; + tp.read_fd = pipe_fd[0]; + g_array_append_val(tids->pids, tp); + /* clean up any processes that have completed */ + tids_sweep_procs(tids); return 0; } +/** + * Clean up any finished TID request processes + * + * This is called by the main process after forking each TID request. If you want to be + * sure finished processes are cleaned up promptly even during a lull in TID requests, + * this can be called from the main thread of the main process. It is not thread-safe, + * so should not be used from sub-threads. It should not be called by child processes - + * this would probably be harmless but ineffective. + * + * @param tids + */ +void tids_sweep_procs(TIDS_INSTANCE *tids) +{ + guint ii; + struct tid_process tp = {0}; + char result[TIDS_MAX_MESSAGE_LEN] = {0}; + ssize_t result_len; + int status; + int wait_rc; + + /* loop backwards over the array so we can remove elements as we go */ + for (ii=tids->pids->len; ii > 0; ii--) { + /* ii-1 is the current index - get our own copy, we may destroy the list's copy */ + tp = g_array_index(tids->pids, struct tid_process, ii-1); + + wait_rc = waitpid(tp.pid, &status, WNOHANG); + if (wait_rc == 0) + continue; /* process still running */ + + if (wait_rc < 0) { + /* invalid options will probably keep being invalid, report that condition */ + if(errno == EINVAL) + tr_crit("tids_sweep_procs: waitpid called with invalid options"); + + /* If we got ECHILD, that means the PID was invalid; we'll assume the process was + * terminated and we missed it. For all other errors, move on + * to the next PID to check. */ + if (errno != ECHILD) + continue; + + tr_warning("tid_sweep_procs: TID process %d disappeared", tp.pid); + } + + /* remove the item (we still have a copy of the data) */ + g_array_remove_index_fast(tids->pids, ii-1); /* disturbs only indices >= ii-1 which we've already handled */ + + /* Report exit status unless we got ECHILD above or somehow waitpid returned the wrong pid */ + if (wait_rc == tp.pid) { + if (WIFEXITED(status)) { + tr_debug("tids_sweep_procs: TID process %d exited with status %d.", tp.pid, WTERMSIG(status)); + } else if (WIFSIGNALED(status)) { + tr_debug("tids_sweep_procs: TID process %d terminated by signal %d.", tp.pid, WTERMSIG(status)); + } + } else if (wait_rc > 0) { + tr_err("tids_sweep_procs: waitpid returned pid %d, expected %d", wait_rc, tp.pid); + } + + /* read the pipe - if the TID request worked, it will have written status before terminating */ + result_len = read(tp.read_fd, result, TIDS_MAX_MESSAGE_LEN); + close(tp.read_fd); + + if ((result_len > 0) && (strcmp(result, TIDS_SUCCESS_MESSAGE) == 0)) { + tids->req_count++; + tr_info("tids_sweep_procs: TID process %d exited successfully.", tp.pid); + } else { + tids->error_count++; + tr_info("tids_sweep_procs: TID process %d exited with an error.", tp.pid); + } + } +} + /* Process tids requests forever. Should not return except on error. */ int tids_start (TIDS_INSTANCE *tids, TIDS_REQ_FUNC *req_handler,