X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libustcomm%2Fustcomm.c;h=4fe46c537d880d7f9cb27dd13d73c1a660343a3e;hb=3a7b90de71f2a82f73f06fb14a7b77805aea1064;hp=3843921cf08933a4e6212f0e31e3762452b69456;hpb=f9e5ce615d925102c8cf44f4fe61ab6aacd92c45;p=ust.git

diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c
index 3843921..4fe46c5 100644
--- a/libustcomm/ustcomm.c
+++ b/libustcomm/ustcomm.c
@@ -1,63 +1,530 @@
+#define _GNU_SOURCE
 #include <sys/types.h>
 #include <signal.h>
 #include <errno.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <unistd.h>
+#include <poll.h>
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <execinfo.h>
+
+#include "ustcomm.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];
+//	int result;
+//
+//	result = backtrace(&buffer, 100);
+//	backtrace_symbols_fd(buffer, result, STDERR_FILENO);
+//}
+
+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 void signal_process(pid_t pid)
 {
 	int result;
 
 	result = kill(pid, UST_SIGNAL);
 	if(result == -1) {
-		perror("kill");
+		PERROR("kill");
 		return;
 	}
 
 	sleep(1);
 }
 
-int send_message(pid_t pid, const char *msg, const char *reply)
+int send_message_fd(int fd, const char *msg, char **reply)
+{
+	int result;
+
+	result = send(fd, msg, strlen(msg), 0);
+	if(result == -1) {
+		PERROR("send");
+		return -1;
+	}
+	else if(result == 0) {
+		return 0;
+	}
+
+	if(!reply)
+		return 1;
+
+	*reply = (char *) malloc(MSG_MAX+1);
+	result = recv(fd, *reply, MSG_MAX, 0);
+	if(result == -1) {
+		PERROR("recv");
+		return -1;
+	}
+	else if(result == 0) {
+		return 0;
+	}
+	
+	(*reply)[result] = '\0';
+
+	return 1;
+}
+
+int send_message_path(const char *path, const char *msg, char **reply, int signalpid)
 {
 	int fd;
 	int result;
 	struct sockaddr_un addr;
-	char *buf;
 
-	result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+	result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
 	if(result == -1) {
-		perror("socket");
-		return 1;
+		PERROR("socket");
+		return -1;
 	}
 
 	addr.sun_family = AF_UNIX;
 
-	result = snprintf(addr.sun_path, UNIX_PATH_MAX, "%s/%d", SOCK_DIR, pid);
+	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);
+
+	result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
+	if(result == -1) {
+		PERROR("connect");
+		return -1;
+	}
+
+	return send_message_fd(fd, msg, reply);
+}
+
+/* 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
+ */
+
+int send_message(pid_t pid, const char *msg, char **reply)
+{
+	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");
-		return 1;
+		return -1;
 	}
 
-	asprintf(&buf, "%s\n", msg);
+	send_message_path(path, msg, reply, pid);
+
+	return 0;
+}
+
+/* Called by an app to ask the consumer daemon to connect to it. */
 
-	signal_process(pid);
+int ustcomm_request_consumer(pid_t pid, const char *channel)
+{
+	char path[UNIX_PATH_MAX];
+	int result;
+	char *msg;
 
-	result = sendto(fd, buf, strlen(buf), 0, (struct sockaddr *)&addr, sizeof(addr));
+	result = snprintf(path, UNIX_PATH_MAX, "%s/ustd", SOCK_DIR);
+	if(result >= UNIX_PATH_MAX) {
+		fprintf(stderr, "string overflow allocating socket name");
+		return -1;
+	}
+
+	asprintf(&msg, "collect %d %s", pid, channel); 
+
+	send_message_path(path, msg, NULL, -1);
+	free(msg);
+
+	return 0;
+}
+
+/* returns 1 to indicate a message was received
+ * returns 0 to indicate no message was received (cannot happen)
+ * returns -1 to indicate an error
+ */
+
+static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src)
+{
+	int result;
+
+	*msg = (char *) malloc(MSG_MAX+1);
+
+	result = recv(fd, *msg, MSG_MAX, 0);
 	if(result == -1) {
-		perror("sendto");
-		return 1;
+		PERROR("recv");
+		return -1;
 	}
 
-	free(buf);
+	(*msg)[result] = '\0';
+	
+	DBG("ustcomm_app_recv_message: result is %d, message is %s", result, (*msg));
+
+	if(src)
+		src->fd = fd;
+
+	return 1;
+}
+
+int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src)
+{
+	int result;
+
+	result = send_message_fd(src->fd, msg, NULL);
+	if(result < 0) {
+		ERR("error in send_message_fd");
+		return -1;
+	}
 
 	return 0;
+} 
+
+/* @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;
+	int retval;
+
+	for(;;) {
+		int idx = 0;
+		int n_fds = 1;
+
+		list_for_each_entry(conn, &server->connections, list) {
+			n_fds++;
+		}
+
+		fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
+		if(fds == NULL) {
+			ERR("malloc returned NULL");
+			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++;
+		}
+
+		result = poll(fds, n_fds, timeout);
+		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);
+	}
+
+free_fds_return:
+	free(fds);
+	return retval;
 }
 
+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_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src, int timeout)
+{
+	return ustcomm_recv_message(&app->server, msg, src, timeout);
+}
+
+/* This removes src from the list of active connections of app.
+ */
+
+int ustcomm_app_detach_client(struct ustcomm_app *app, struct ustcomm_source *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)
+{
+	int result;
+	int fd;
+
+	struct sockaddr_un addr;
+	
+	result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
+	if(result == -1) {
+		PERROR("socket");
+		return -1;
+	}
+
+	addr.sun_family = AF_UNIX;
+
+	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);
+	}
+
+	return fd;
+
+	close_sock:
+	close(fd);
+
+	return -1;
+}
+
+int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle)
+{
+	int result;
+	char *name;
+
+	result = asprintf(&name, "%s/%d", SOCK_DIR, (int)pid);
+	if(result >= UNIX_PATH_MAX) {
+		ERR("string overflow allocating socket name");
+		return -1;
+	}
+
+	handle->server.listen_fd = init_named_socket(name, &(handle->server.socketpath));
+	if(handle->server.listen_fd < 0) {
+		ERR("error initializing named socket");
+		goto free_name;
+	}
+	free(name);
+
+	INIT_LIST_HEAD(&handle->server.connections);
+
+	return 0;
+
+free_name:
+	free(name);
+	return -1;
+}
+
+int ustcomm_init_ustd(struct ustcomm_ustd *handle)
+{
+	int result;
+	char *name;
+
+	result = asprintf(&name, "%s/%s", SOCK_DIR, "ustd");
+	if(result >= UNIX_PATH_MAX) {
+		ERR("string overflow allocating socket name");
+		return -1;
+	}
+
+	handle->server.listen_fd = init_named_socket(name, &handle->server.socketpath);
+	if(handle->server.listen_fd < 0) {
+		ERR("error initializing named socket");
+		goto free_name;
+	}
+	free(name);
+
+	INIT_LIST_HEAD(&handle->server.connections);
+
+	return 0;
+
+free_name:
+	free(name);
+	return -1;
+}
+
+static char *find_tok(char *str)
+{
+	while(*str == ' ') {
+		str++;
+
+		if(*str == 0)
+			return NULL;
+	}
+
+	return str;
+}
+
+static char *find_sep(char *str)
+{
+	while(*str != ' ') {
+		str++;
+
+		if(*str == 0)
+			break;
+	}
+
+	return str;
+}
+
+int nth_token_is(char *str, char *token, int tok_no)
+{
+	int i;
+	char *start;
+	char *end;
+
+	for(i=0; i<=tok_no; i++) {
+		str = find_tok(str);
+		if(str == NULL)
+			return -1;
+
+		start = str;
+
+		str = find_sep(str);
+		if(str == NULL)
+			return -1;
+
+		end = str;
+	}
+
+	if(end-start != strlen(token))
+		return 0;
+
+	if(strncmp(start, token, end-start))
+		return 0;
+
+	return 1;
+}
+
+char *nth_token(char *str, int tok_no)
+{
+	static char *retval = NULL;
+	int i;
+	char *start;
+	char *end;
+
+	for(i=0; i<=tok_no; i++) {
+		str = find_tok(str);
+		if(str == NULL)
+			return NULL;
+
+		start = str;
+
+		str = find_sep(str);
+		if(str == NULL)
+			return NULL;
+
+		end = str;
+	}
+
+	if(retval) {
+		free(retval);
+		retval = NULL;
+	}
+
+	asprintf(&retval, "%.*s", (int)(end-start), start);
+
+	return retval;
+}