+/* Copyright (C) 2009 Pierre-Marc Fournier
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
#define _GNU_SOURCE
#include <sys/types.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
+#include <poll.h>
+#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include "localerr.h"
#define UNIX_PATH_MAX 108
-#define SOCK_DIR "/tmp/socks"
-#define UST_SIGNAL SIGIO
#define MSG_MAX 1000
+/* FIXME: ustcomm blocks on message sending, which might be problematic in
+ * some cases. Fix the poll() usage so sends are buffered until they don't
+ * block.
+ */
+
//static void bt(void)
//{
// void *buffer[100];
// backtrace_symbols_fd(buffer, result, STDERR_FILENO);
//}
-static void signal_process(pid_t pid)
+char *strdup_malloc(const char *s)
+{
+ char *retval;
+
+ if(s == NULL)
+ return NULL;
+
+ retval = (char *) malloc(strlen(s)+1);
+
+ strcpy(retval, s);
+
+ return retval;
+}
+
+static int signal_process(pid_t pid)
{
int result;
result = kill(pid, UST_SIGNAL);
if(result == -1) {
PERROR("kill");
- return;
+ return -1;
}
- sleep(1);
+ /* FIXME: should wait in a better way */
+ //sleep(1);
+
+ return 0;
+}
+
+int pid_is_online(pid_t pid) {
+ return kill(pid, UST_SIGNAL) != -1;
}
-int send_message_path(const char *path, const char *msg, char **reply, int signalpid)
+static int send_message_fd(int fd, const char *msg)
{
- int fd;
int result;
- struct sockaddr_un addr;
- result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+ result = send(fd, msg, strlen(msg), 0);
if(result == -1) {
- PERROR("socket");
+ PERROR("send");
return -1;
}
+ else if(result == 0) {
+ return 0;
+ }
- addr.sun_family = AF_UNIX;
+ return 1;
+}
+
+/* Called by an app to ask the consumer daemon to connect to it. */
+
+int ustcomm_request_consumer(pid_t pid, const char *channel)
+{
+ char path[UNIX_PATH_MAX];
+ int result;
+ char *msg=NULL;
+ int retval = 0;
+ struct ustcomm_connection conn;
+ char *explicit_daemon_socket_path;
+
+ explicit_daemon_socket_path = getenv("UST_DAEMON_SOCKET");
+ if(explicit_daemon_socket_path) {
+ /* user specified explicitly a socket path */
+ result = snprintf(path, UNIX_PATH_MAX, "%s", explicit_daemon_socket_path);
+ }
+ else {
+ /* just use the default path */
+ result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR);
+ }
- result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s", path);
if(result >= UNIX_PATH_MAX) {
ERR("string overflow allocating socket name");
return -1;
}
- if(signalpid >= 0)
- signal_process(signalpid);
+ asprintf(&msg, "collect %d %s", pid, channel);
- result = sendto(fd, msg, strlen(msg), 0, (struct sockaddr *)&addr, sizeof(addr));
+ /* don't signal it because it's the daemon */
+ result = ustcomm_connect_path(path, &conn, -1);
if(result == -1) {
- PERROR("sendto");
- return -1;
+ WARN("ustcomm_connect_path failed");
+ retval = -1;
+ goto del_string;
}
- if(!reply)
- return 0;
-
- *reply = (char *) malloc(MSG_MAX+1);
- result = recvfrom(fd, *reply, MSG_MAX, 0, NULL, NULL);
+ result = ustcomm_send_request(&conn, msg, NULL);
if(result == -1) {
- PERROR("recvfrom");
- return -1;
+ WARN("ustcomm_send_request failed");
+ retval = -1;
+ goto disconnect;
}
-
- (*reply)[result] = '\0';
- return 0;
+ disconnect:
+ ustcomm_disconnect(&conn);
+ del_string:
+ free(msg);
+
+ return retval;
}
-/* pid: the pid of the trace process that must receive the msg
- msg: pointer to a null-terminated message to send
- reply: location where to put the null-terminated string of the reply;
- it must be free'd after usage
+/* returns 1 to indicate a message was received
+ * returns 0 to indicate no message was received (cannot happen)
+ * returns -1 to indicate an error
*/
-int send_message(pid_t pid, const char *msg, char **reply)
+static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src)
{
int result;
- char path[UNIX_PATH_MAX];
- result = snprintf(path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid);
- if(result >= UNIX_PATH_MAX) {
- fprintf(stderr, "string overflow allocating socket name");
+ *msg = (char *) malloc(MSG_MAX+1);
+
+ result = recv(fd, *msg, MSG_MAX, 0);
+ if(result == -1) {
+ PERROR("recv");
return -1;
}
- send_message_path(path, msg, reply, pid);
+ (*msg)[result] = '\0';
+
+ DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg));
- return 0;
-}
+ if(src)
+ src->fd = fd;
-/* Called by an app to ask the consumer daemon to connect to it. */
+ return 1;
+}
-int ustcomm_request_consumer(pid_t pid, const char *channel)
+int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src)
{
- char path[UNIX_PATH_MAX];
int result;
- char *msg;
- result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR);
- if(result >= UNIX_PATH_MAX) {
- fprintf(stderr, "string overflow allocating socket name");
+ result = send_message_fd(src->fd, msg);
+ if(result < 0) {
+ ERR("error in send_message_fd");
return -1;
}
- asprintf(&msg, "collect %d %s", pid, channel);
+ return 0;
+}
- send_message_path(path, msg, NULL, -1);
- free(msg);
+/* Called after a fork. */
+
+int ustcomm_close_all_connections(struct ustcomm_server *server)
+{
+ struct ustcomm_connection *conn;
+ struct ustcomm_connection *deletable_conn = NULL;
+
+ list_for_each_entry(conn, &server->connections, list) {
+ free(deletable_conn);
+ deletable_conn = conn;
+ close(conn->fd);
+ list_del(&conn->list);
+ }
return 0;
}
-static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src)
+/* @timeout: max blocking time in milliseconds, -1 means infinity
+ *
+ * returns 1 to indicate a message was received
+ * returns 0 to indicate no message was received
+ * returns -1 to indicate an error
+ */
+
+int ustcomm_recv_message(struct ustcomm_server *server, char **msg, struct ustcomm_source *src, int timeout)
{
+ struct pollfd *fds;
+ struct ustcomm_connection *conn;
int result;
- size_t initial_addrlen,addrlen;
+ int retval;
- *msg = (char *) malloc(MSG_MAX+1);
+ for(;;) {
+ int idx = 0;
+ int n_fds = 1;
- if(src) {
- initial_addrlen = addrlen = sizeof(src->addr);
+ list_for_each_entry(conn, &server->connections, list) {
+ n_fds++;
+ }
- result = recvfrom(fd, *msg, MSG_MAX, 0, &src->addr, &addrlen);
- if(initial_addrlen != addrlen) {
- ERR("recvfrom: unexpected address length");
+ fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
+ if(fds == NULL) {
+ ERR("malloc returned NULL");
return -1;
}
- }
- else {
- result = recvfrom(fd, *msg, MSG_MAX, 0, NULL, NULL);
- }
- if(result == -1) {
- PERROR("recvfrom");
- return -1;
+ /* special idx 0 is for listening socket */
+ fds[idx].fd = server->listen_fd;
+ fds[idx].events = POLLIN;
+ idx++;
+
+ list_for_each_entry(conn, &server->connections, list) {
+ fds[idx].fd = conn->fd;
+ fds[idx].events = POLLIN;
+ idx++;
+ }
+
+ while((result = poll(fds, n_fds, timeout)) == -1 && errno == EINTR)
+ /* nothing */;
+ if(result == -1) {
+ PERROR("poll");
+ return -1;
+ }
+
+ if(result == 0)
+ return 0;
+
+ if(fds[0].revents) {
+ struct ustcomm_connection *newconn;
+ int newfd;
+
+ result = newfd = accept(server->listen_fd, NULL, NULL);
+ if(result == -1) {
+ PERROR("accept");
+ return -1;
+ }
+
+ newconn = (struct ustcomm_connection *) malloc(sizeof(struct ustcomm_connection));
+ if(newconn == NULL) {
+ ERR("malloc returned NULL");
+ return -1;
+ }
+
+ newconn->fd = newfd;
+
+ list_add(&newconn->list, &server->connections);
+ }
+
+ for(idx=1; idx<n_fds; idx++) {
+ if(fds[idx].revents) {
+ retval = recv_message_fd(fds[idx].fd, msg, src);
+ if(**msg == 0) {
+ /* connection finished */
+ close(fds[idx].fd);
+
+ list_for_each_entry(conn, &server->connections, list) {
+ if(conn->fd == fds[idx].fd) {
+ list_del(&conn->list);
+ break;
+ }
+ }
+ }
+ else {
+ goto free_fds_return;
+ }
+ }
+ }
+
+ free(fds);
}
- (*msg)[result] = '\0';
-
- DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg));
+free_fds_return:
+ free(fds);
+ return retval;
+}
- return 0;
+int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src, int timeout)
+{
+ return ustcomm_recv_message(&ustd->server, msg, src, timeout);
}
-int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src)
+int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout)
{
- return recv_message_fd(ustd->fd, msg, src);
+ return ustcomm_recv_message(&app->server, msg, src, timeout);
}
-int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src)
+/* This removes src from the list of active connections of app.
+ */
+
+int ustcomm_app_detach_client(struct ustcomm_app *app, struct ustcomm_source *src)
{
- return recv_message_fd(app->fd, msg, src);
+ struct ustcomm_server *server = (struct ustcomm_server *)app;
+ struct ustcomm_connection *conn;
+
+ list_for_each_entry(conn, &server->connections, list) {
+ if(conn->fd == src->fd) {
+ list_del(&conn->list);
+ goto found;
+ }
+ }
+
+ return -1;
+found:
+ return src->fd;
}
-static int init_named_socket(char *name, char **path_out)
+static int init_named_socket(const char *name, char **path_out)
{
int result;
int fd;
struct sockaddr_un addr;
- result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+ result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
if(result == -1) {
PERROR("socket");
return -1;
strncpy(addr.sun_path, name, UNIX_PATH_MAX);
addr.sun_path[UNIX_PATH_MAX-1] = '\0';
+ result = access(name, F_OK);
+ if(result == 0) {
+ /* file exists */
+ result = unlink(name);
+ if(result == -1) {
+ PERROR("unlink of socket file");
+ goto close_sock;
+ }
+ WARN("socket already exists; overwriting");
+ }
+
result = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
if(result == -1) {
PERROR("bind");
goto close_sock;
}
+ result = listen(fd, 1);
+ if(result == -1) {
+ PERROR("listen");
+ goto close_sock;
+ }
+
if(path_out) {
- *path_out = "";
- *path_out = strdupa(addr.sun_path);
+ *path_out = strdup(addr.sun_path);
}
return fd;
return -1;
}
+/*
+ * Return value:
+ * 0: Success, but no reply because recv() returned 0
+ * 1: Success
+ * -1: Error
+ *
+ * On error, the error message is printed, except on
+ * ECONNRESET, which is normal when the application dies.
+ */
+
+int ustcomm_send_request(struct ustcomm_connection *conn, const char *req, char **reply)
+{
+ int result;
+
+ result = send(conn->fd, req, strlen(req), MSG_NOSIGNAL);
+ if(result == -1) {
+ if(errno != EPIPE)
+ PERROR("send");
+ return -1;
+ }
+
+ if(!reply)
+ return 1;
+
+ *reply = (char *) malloc(MSG_MAX+1);
+ result = recv(conn->fd, *reply, MSG_MAX, 0);
+ if(result == -1) {
+ if(errno != ECONNRESET)
+ PERROR("recv");
+ return -1;
+ }
+ else if(result == 0) {
+ return 0;
+ }
+
+ (*reply)[result] = '\0';
+
+ return 1;
+}
+
+int ustcomm_connect_path(const char *path, struct ustcomm_connection *conn, pid_t signalpid)
+{
+ int fd;
+ int result;
+ struct sockaddr_un addr;
+
+ result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if(result == -1) {
+ PERROR("socket");
+ return -1;
+ }
+
+ addr.sun_family = AF_UNIX;
+
+ result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s", path);
+ if(result >= UNIX_PATH_MAX) {
+ ERR("string overflow allocating socket name");
+ return -1;
+ }
+
+ if(signalpid >= 0) {
+ result = signal_process(signalpid);
+ if(result == -1) {
+ ERR("could not signal process");
+ return -1;
+ }
+ }
+
+ result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
+ if(result == -1) {
+ PERROR("connect");
+ return -1;
+ }
+
+ conn->fd = fd;
+
+ return 0;
+}
+
+int ustcomm_disconnect(struct ustcomm_connection *conn)
+{
+ return close(conn->fd);
+}
+
+int ustcomm_connect_app(pid_t pid, struct ustcomm_connection *conn)
+{
+ int result;
+ char path[UNIX_PATH_MAX];
+
+
+ result = snprintf(path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid);
+ if(result >= UNIX_PATH_MAX) {
+ ERR("string overflow allocating socket name");
+ return -1;
+ }
+
+ return ustcomm_connect_path(path, conn, pid);
+}
+
+/* Called by an application to initialize its server so daemons can
+ * connect to it.
+ */
+
int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle)
{
int result;
return -1;
}
- handle->fd = init_named_socket(name, &(handle->socketpath));
- if(handle->fd < 0) {
+ handle->server.listen_fd = init_named_socket(name, &(handle->server.socketpath));
+ if(handle->server.listen_fd < 0) {
+ ERR("Error initializing named socket (%s). Check that directory exists and that it is writable.", name);
goto free_name;
}
free(name);
+ INIT_LIST_HEAD(&handle->server.connections);
+
return 0;
free_name:
return -1;
}
-int ustcomm_init_ustd(struct ustcomm_ustd *handle)
+/* Used by the daemon to initialize its server so applications
+ * can connect to it.
+ */
+
+int ustcomm_init_ustd(struct ustcomm_ustd *handle, const char *sock_path)
{
- int result;
char *name;
+ int retval = 0;
- result = asprintf(&name, "%s/%s", SOCK_DIR, "ustd");
- if(result >= UNIX_PATH_MAX) {
- ERR("string overflow allocating socket name");
- return -1;
+ if(sock_path) {
+ asprintf(&name, "%s", sock_path);
+ }
+ else {
+ asprintf(&name, "%s/%s", SOCK_DIR, "ustd");
+ }
+
+ handle->server.listen_fd = init_named_socket(name, &handle->server.socketpath);
+ if(handle->server.listen_fd < 0) {
+ ERR("error initializing named socket at %s", name);
+ retval = -1;
+ goto free_name;
}
- handle->fd = init_named_socket(name, &handle->socketpath);
- if(handle->fd < 0)
- return handle->fd;
+ INIT_LIST_HEAD(&handle->server.connections);
+
+free_name:
free(name);
- return 0;
+ return retval;
+}
+
+void ustcomm_fini_app(struct ustcomm_app *handle)
+{
+ int result;
+ struct stat st;
+
+ /* Destroy socket */
+ result = stat(handle->server.socketpath, &st);
+ if(result == -1) {
+ PERROR("stat (%s)", handle->server.socketpath);
+ return;
+ }
+
+ /* Paranoid check before deleting. */
+ result = S_ISSOCK(st.st_mode);
+ if(!result) {
+ ERR("The socket we are about to delete is not a socket.");
+ return;
+ }
+
+ result = unlink(handle->server.socketpath);
+ if(result == -1) {
+ PERROR("unlink");
+ }
}
-char *find_tok(const char *str)
+static char *find_tok(char *str)
{
while(*str == ' ') {
str++;
retval = NULL;
}
- retval = strndupa(start, end-start);
+ asprintf(&retval, "%.*s", (int)(end-start), start);
return retval;
}
projects / ust.git / blobdiff