ust: change communication socket for STREAM

diff --git a/libtracectl/localerr.h b/libtracectl/localerr.h
new file mode 100644 (file)
index 0000000..eef0d4f
--- /dev/null
+++ b/libtracectl/localerr.h
@@ -0,0 +1 @@
+#include "usterr.h"

diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c
index c944214ae2ea93aec91febf836e6b8018bc873d5..2773b1a0a4fc7c299a95e3a6897a993c5eefbb60 100644 (file)
--- a/libustcomm/ustcomm.c
+++ b/libustcomm/ustcomm.c
@@ -5,6 +5,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
+#include <poll.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,6 +21,11 @@
 
 #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];
@@ -48,7 +54,7 @@ int send_message_path(const char *path, const char *msg, char **reply, int signa
        int result;
        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;
@@ -65,9 +71,15 @@ int send_message_path(const char *path, const char *msg, char **reply, int signa
        if(signalpid >= 0)
                signal_process(signalpid);
 
-       result = sendto(fd, msg, strlen(msg), 0, (struct sockaddr *)&addr, sizeof(addr));
+       result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
        if(result == -1) {
-               PERROR("sendto");
+               PERROR("connect");
+               return -1;
+       }
+
+       result = send(fd, msg, strlen(msg), 0);
+       if(result == -1) {
+               PERROR("send");
                return -1;
        }
 
@@ -133,23 +145,10 @@ int ustcomm_request_consumer(pid_t pid, const char *channel)
 static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src)
 {
        int result;
-       size_t initial_addrlen,addrlen;
 
        *msg = (char *) malloc(MSG_MAX+1);
 
-       if(src) {
-               initial_addrlen = addrlen = sizeof(src->addr);
-
-               result = recvfrom(fd, *msg, MSG_MAX, 0, &src->addr, &addrlen);
-               if(initial_addrlen != addrlen) {
-                       ERR("recvfrom: unexpected address length");
-                       return -1;
-               }
-       }
-       else {
-               result = recvfrom(fd, *msg, MSG_MAX, 0, NULL, NULL);
-       }
-
+       result = recv(fd, *msg, MSG_MAX, 0);
        if(result == -1) {
                PERROR("recvfrom");
                return -1;
@@ -164,12 +163,94 @@ static int recv_message_fd(int fd, char **msg, struct ustcomm_source *src)
 
 int ustcomm_ustd_recv_message(struct ustcomm_ustd *ustd, char **msg, struct ustcomm_source *src)
 {
-       return recv_message_fd(ustd->fd, msg, src);
+       struct pollfd *fds;
+       struct ustcomm_connection *conn;
+       int result;
+       int retval;
+
+       for(;;) {
+               int idx = 0;
+               int n_fds = 1;
+
+               list_for_each_entry(conn, &ustd->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 = ustd->listen_fd;
+               fds[idx].events = POLLIN;
+               idx++;
+
+               list_for_each_entry(conn, &ustd->connections, list) {
+                       fds[idx].fd = conn->fd;
+                       fds[idx].events = POLLIN;
+                       idx++;
+               }
+
+               result = poll(fds, n_fds, -1);
+               if(result == -1) {
+                       PERROR("poll");
+                       return -1;
+               }
+
+               if(fds[0].revents) {
+                       struct ustcomm_connection *newconn;
+                       int newfd;
+
+                       result = newfd = accept(ustd->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, &ustd->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, &ustd->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_app_recv_message(struct ustcomm_app *app, char **msg, struct ustcomm_source *src)
 {
-       return recv_message_fd(app->fd, msg, src);
+       return ustcomm_ustd_recv_message((struct ustcomm_ustd *)app, msg, src);
 }
 
 static int init_named_socket(char *name, char **path_out)
@@ -179,7 +260,7 @@ static int init_named_socket(char *name, char **path_out)
 
        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;
@@ -190,12 +271,29 @@ static int init_named_socket(char *name, char **path_out)
        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);
@@ -220,12 +318,15 @@ int ustcomm_init_app(pid_t pid, struct ustcomm_app *handle)
                return -1;
        }
 
-       handle->fd = init_named_socket(name, &(handle->socketpath));
-       if(handle->fd < 0) {
+       handle->listen_fd = init_named_socket(name, &(handle->socketpath));
+       if(handle->listen_fd < 0) {
+               ERR("error initializing named socket");
                goto free_name;
        }
        free(name);
 
+       INIT_LIST_HEAD(&handle->connections);
+
        return 0;
 
 free_name:
@@ -244,15 +345,23 @@ int ustcomm_init_ustd(struct ustcomm_ustd *handle)
                return -1;
        }
 
-       handle->fd = init_named_socket(name, &handle->socketpath);
-       if(handle->fd < 0)
-               return handle->fd;
+       handle->listen_fd = init_named_socket(name, &handle->socketpath);
+       if(handle->listen_fd < 0) {
+               ERR("error initializing named socket");
+               goto free_name;
+       }
        free(name);
 
+       INIT_LIST_HEAD(&handle->connections);
+
        return 0;
+
+free_name:
+       free(name);
+       return -1;
 }
 
-char *find_tok(const char *str)
+static char *find_tok(char *str)
 {
        while(*str == ' ') {
                str++;
@@ -331,7 +440,7 @@ char *nth_token(char *str, int tok_no)
                retval = NULL;
        }
 
-       retval = strndupa(start, end-start);
+       asprintf(&retval, "%.*s", (int)(end-start), start);
 
        return retval;
 }

diff --git a/libustcomm/ustcomm.h b/libustcomm/ustcomm.h
index 53ced5140c962d604fc50992350db50dda48ba6b..7d845920fe0d0b57dd438b24f1ef0d0a8827af2b 100644 (file)
--- a/libustcomm/ustcomm.h
+++ b/libustcomm/ustcomm.h
@@ -4,16 +4,27 @@
 #include <sys/types.h>
 #include <sys/un.h>
 
+#include "kcompat.h"
+
+struct ustcomm_connection {
+       struct list_head list;
+       int fd;
+};
+
 struct ustcomm_app {
        /* the "server" socket for serving the external requests */
-       int fd;
+       int listen_fd;
        char *socketpath;
+
+       struct list_head connections;
 };
 
 struct ustcomm_ustd {
        /* the "server" socket for serving the external requests */
-       int fd;
+       int listen_fd;
        char *socketpath;
+
+       struct list_head connections;
 };
 
 struct ustcomm_source {

diff --git a/share/usterr.c b/share/usterr.c
new file mode 100644 (file)
index 0000000..ee7aeb0
--- /dev/null
+++ b/share/usterr.c
@@ -0,0 +1,18 @@
+#include <stdarg.h>
+#include <unistd.h>
+
+int safe_printf(const char *fmt, ...)
+{
+       static char buf[500];
+       va_list ap;
+       int n;
+
+       va_start(ap, fmt);
+
+       n = vsnprintf(buf, sizeof(buf), fmt, ap);
+
+       write(STDOUT_FILENO, buf, n);
+
+       va_end(ap);
+}
+

diff --git a/ust/Makefile b/ust/Makefile
new file mode 100644 (file)
index 0000000..3aeec04
--- /dev/null
+++ b/ust/Makefile
@@ -0,0 +1,6 @@
+all: ust
+
+ust: ust.c
+       gcc -g -Wall -I ../libustcomm -I. -I ../../../../libkcompat -o ust ust.c ../libustcomm/ustcomm.c
+
+.PHONY: ust

diff --git a/ust/localerr.h b/ust/localerr.h
new file mode 100644 (file)
index 0000000..7fe99e2
--- /dev/null
+++ b/ust/localerr.h
@@ -0,0 +1,11 @@
+#ifndef LOCALERR_H
+#define LOCALERR_H
+
+#include <stdio.h>
+
+#define DBG(fmt, args...) fprintf(stderr, "ustd: " fmt "\n", ## args); fflush(stderr)
+#define WARN(fmt, args...) fprintf(stderr, "ustd: WARNING: " fmt "\n", ## args); fflush(stderr)
+#define ERR(fmt, args...) fprintf(stderr, "ustd: ERROR: " fmt "\n", ## args); fflush(stderr)
+#define PERROR(a) perror(a)
+
+#endif /* LOCALERR_H */