Handle application context cmd

[deliverable/lttng-ust.git] / liblttng-ust / lttng-ust-comm.c

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 1387aa82197f63e43dad5439368bec214fc2c1ae..3108e3826a4ed80eda4f7e425e6f1b64b73a8b7f 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -588,6 +588,7 @@ int handle_message(struct sock_info *sock_info,
        const struct lttng_ust_objd_ops *ops;
        struct ustcomm_ust_reply lur;
        union ust_args args;
+       char ctxstr[LTTNG_UST_SYM_NAME_LEN];    /* App context string. */
        ssize_t len;
 
        memset(&lur, 0, sizeof(lur));
@@ -807,6 +808,64 @@ int handle_message(struct sock_info *sock_info,
                        ret = -ENOSYS;
                break;
        }
+       case LTTNG_UST_CONTEXT:
+               switch (lum->u.context.ctx) {
+               case LTTNG_UST_CONTEXT_APP_CONTEXT:
+               {
+                       char *p;
+                       size_t ctxlen, recvlen;
+
+                       ctxlen = strlen("$app.") + lum->u.context.u.app_ctx.provider_name_len - 1
+                                       + strlen(":") + lum->u.context.u.app_ctx.ctx_name_len;
+                       if (ctxlen >= LTTNG_UST_SYM_NAME_LEN) {
+                               ERR("Application context string length size is too large: %zu bytes",
+                                       ctxlen);
+                               ret = -EINVAL;
+                               goto error;
+                       }
+                       strcpy(ctxstr, "$app.");
+                       p = &ctxstr[strlen("$app.")];
+                       recvlen = ctxlen - strlen("$app.");
+                       len = ustcomm_recv_unix_sock(sock, p, recvlen);
+                       switch (len) {
+                       case 0: /* orderly shutdown */
+                               ret = 0;
+                               goto error;
+                       default:
+                               if (len == recvlen) {
+                                       DBG("app context data received");
+                                       break;
+                               } else if (len < 0) {
+                                       DBG("Receive failed from lttng-sessiond with errno %d", (int) -len);
+                                       if (len == -ECONNRESET) {
+                                               ERR("%s remote end closed connection", sock_info->name);
+                                               ret = len;
+                                               goto error;
+                                       }
+                                       ret = len;
+                                       goto error;
+                               } else {
+                                       DBG("incorrect app context data message size: %zd", len);
+                                       ret = -EINVAL;
+                                       goto error;
+                               }
+                       }
+                       /* Put : between provider and ctxname. */
+                       p[lum->u.context.u.app_ctx.provider_name_len - 1] = ':';
+                       args.app_context.ctxname = ctxstr;
+                       break;
+               }
+               default:
+                       break;
+               }
+               if (ops->cmd) {
+                       ret = ops->cmd(lum->handle, lum->cmd,
+                                       (unsigned long) &lum->u,
+                                       &args, sock_info);
+               } else {
+                       ret = -ENOSYS;
+               }
+               break;
        default:
                if (ops->cmd)
                        ret = ops->cmd(lum->handle, lum->cmd,