ust: continue moving communication stuff to libustcomm and cleanup

[ust.git] / libustcomm / ustcomm.c

diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c
index 3843921cf08933a4e6212f0e31e3762452b69456..380df2f51a645fc1a8f56680322ff44c3455c6e7 100644 (file)
--- a/libustcomm/ustcomm.c
+++ b/libustcomm/ustcomm.c
@@ -1,16 +1,24 @@
+#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 <stdio.h>
 #include <stdlib.h>
+#include <string.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
+
 static void signal_process(pid_t pid)
 {
        int result;
@@ -24,17 +32,22 @@ static void signal_process(pid_t pid)
        sleep(1);
 }
 
-int send_message(pid_t pid, const char *msg, const char *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 fd;
        int result;
        struct sockaddr_un addr;
-       char *buf;
 
        result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
        if(result == -1) {
                perror("socket");
-               return 1;
+               return -1;
        }
 
        addr.sun_family = AF_UNIX;
@@ -42,22 +55,115 @@ int send_message(pid_t pid, const char *msg, const char *reply)
        result = snprintf(addr.sun_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);
-
        signal_process(pid);
 
-       result = sendto(fd, buf, strlen(buf), 0, (struct sockaddr *)&addr, sizeof(addr));
+       result = sendto(fd, msg, strlen(msg), 0, (struct sockaddr *)&addr, sizeof(addr));
        if(result == -1) {
                perror("sendto");
-               return 1;
+               return -1;
        }
 
-       free(buf);
+       if(!reply)
+               return 0;
+
+       *reply = (char *) malloc(MSG_MAX+1);
+       result = recvfrom(fd, *reply, MSG_MAX, 0, NULL, NULL);
+       if(result == -1) {
+               perror("recvfrom");
+               return -1;
+       }
+       
+       (*reply)[result] = '\0';
 
        return 0;
 }
 
+int ustcomm_app_recv_message(struct ustcomm_app *app, char **msg)
+{
+       int fd;
+       int result;
+       struct sockaddr_un addr;
+
+       *msg = (char *) malloc(MSG_MAX+1);
+       result = recvfrom(app->fd, *msg, MSG_MAX, 0, NULL, NULL);
+       if(result == -1) {
+               PERROR("recvfrom");
+               return -1;
+       }
+       
+       DBG("ustcomm_app_recv_message: result is %d, message[1] is %hhd", result, (*msg)[1]);
+       (*msg)[result] = '\0';
 
+       return 0;
+}
+
+static int init_named_socket(char *name, char **path_out)
+{
+       int result;
+       int fd;
+
+       struct sockaddr_un addr;
+       
+       result = fd = socket(PF_UNIX, SOCK_DGRAM, 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 = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
+       if(result == -1) {
+               PERROR("bind");
+               goto close_sock;
+       }
+
+       if(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->fd = init_named_socket(name, &handle->socketpath);
+       if(handle->fd < 0) {
+               goto free_name;
+       }
+       free(name);
+
+       return 0;
+
+free_name:
+       free(name);
+       return -1;
+}
+
+int ustcomm_init_ustd(struct ustcomm_ustd *handle)
+{
+       handle->fd = init_named_socket("ustd", &handle->socketpath);
+       if(handle->fd < 0)
+               return handle->fd;
+
+       return 0;
+}