uprobe: transmit binary file descritptor through lttng_payload
[lttng-tools.git] / src / bin / lttng-sessiond / client.c
index 0238538501b04117cae42280b01a57d3a3c647c3..74bbbe9b2e05e3be7f94a1cba1330aae6d7658ba 100644 (file)
@@ -14,6 +14,8 @@
 #include "common/payload.h"
 #include "common/payload-view.h"
 #include "common/sessiond-comm/sessiond-comm.h"
+#include "common/payload.h"
+#include "common/payload-view.h"
 #include "lttng/lttng-error.h"
 #include "lttng/tracker.h"
 #include <common/compat/getenv.h>
@@ -90,6 +92,7 @@ static int setup_lttng_msg(struct command_ctx *cmd_ctx,
        };
 
        lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
+       lttng_dynamic_array_clear(&cmd_ctx->reply_payload._fds);
 
        cmd_ctx->lttng_msg_size = total_msg_size;
 
@@ -124,6 +127,48 @@ end:
        return ret;
 }
 
+static int setup_empty_lttng_msg(struct command_ctx *cmd_ctx)
+{
+       int ret;
+       const struct lttcomm_lttng_msg llm = {};
+
+       lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
+
+       /* Append place-holder reply header. */
+       ret = lttng_dynamic_buffer_append(
+                       &cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
+       if (ret) {
+               goto end;
+       }
+
+       cmd_ctx->lttng_msg_size = sizeof(llm);
+end:
+       return ret;
+}
+
+static void update_lttng_msg(struct command_ctx *cmd_ctx, size_t cmd_header_len,
+               size_t payload_len)
+{
+       const size_t header_len = sizeof(struct lttcomm_lttng_msg);
+       const size_t total_msg_size = header_len + cmd_header_len + payload_len;
+       const struct lttcomm_lttng_msg llm = {
+               .cmd_type = cmd_ctx->lsm.cmd_type,
+               .pid = cmd_ctx->lsm.domain.attr.pid,
+               .cmd_header_size = cmd_header_len,
+               .data_size = payload_len,
+       };
+       struct lttcomm_lttng_msg *p_llm;
+
+       assert(cmd_ctx->reply_payload.buffer.size >= sizeof(llm));
+
+       p_llm = (typeof(p_llm)) cmd_ctx->reply_payload.buffer.data;
+
+       /* Update existing header. */
+       memcpy(p_llm, &llm, sizeof(llm));
+
+       cmd_ctx->lttng_msg_size = total_msg_size;
+}
+
 /*
  * Start the thread_manage_consumer. This must be done after a lttng-consumerd
  * exec or it will fail.
@@ -549,16 +594,15 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
 {
        int fd, ret;
        struct lttng_userspace_probe_location *probe_location;
-       const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
-       struct lttng_dynamic_buffer probe_location_buffer;
-       struct lttng_buffer_view buffer_view;
+       struct lttng_payload probe_location_payload;
 
        /*
-        * Create a buffer to store the serialized version of the probe
+        * Create a payload to store the serialized version of the probe
         * location.
         */
-       lttng_dynamic_buffer_init(&probe_location_buffer);
-       ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
+       lttng_payload_init(&probe_location_payload);
+
+       ret = lttng_dynamic_buffer_set_size(&probe_location_payload.buffer,
                        cmd_ctx->lsm.u.enable.userspace_probe_location_len);
        if (ret) {
                ret = LTTNG_ERR_NOMEM;
@@ -568,27 +612,11 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
        /*
         * Receive the probe location.
         */
-       ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
-                       probe_location_buffer.size);
+       ret = lttcomm_recv_unix_sock(sock, probe_location_payload.buffer.data,
+                       probe_location_payload.buffer.size);
        if (ret <= 0) {
                DBG("Nothing recv() from client var len data... continuing");
                *sock_error = 1;
-               lttng_dynamic_buffer_reset(&probe_location_buffer);
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       buffer_view = lttng_buffer_view_from_dynamic_buffer(
-                       &probe_location_buffer, 0, probe_location_buffer.size);
-
-       /*
-        * Extract the probe location from the serialized version.
-        */
-       ret = lttng_userspace_probe_location_create_from_buffer(
-                               &buffer_view, &probe_location);
-       if (ret < 0) {
-               WARN("Failed to create a userspace probe location from the received buffer");
-               lttng_dynamic_buffer_reset( &probe_location_buffer);
                ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
                goto error;
        }
@@ -605,35 +633,23 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
                goto error;
        }
 
-       /*
-        * Set the file descriptor received from the client through the unix
-        * socket in the probe location.
-        */
-       lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
-       if (!lookup) {
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+       ret = lttng_payload_push_fd(&probe_location_payload, fd);
+       if (ret) {
+               ERR("Failed to add userspace probe file descriptor to payload");
+               ret = LTTNG_ERR_NOMEM;
                goto error;
        }
 
-       /*
-        * From the kernel tracer's perspective, all userspace probe event types
-        * are all the same: a file and an offset.
-        */
-       switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
-       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
-               ret = lttng_userspace_probe_location_function_set_binary_fd(
-                               probe_location, fd);
-               break;
-       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
-               ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
-                               probe_location, fd);
-               break;
-       default:
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
+       {
+               struct lttng_payload_view view = lttng_payload_view_from_payload(
+                       &probe_location_payload, 0, -1);
 
-       if (ret) {
+               /* Extract the probe location from the serialized version. */
+               ret = lttng_userspace_probe_location_create_from_payload(
+                               &view, &probe_location);
+       }
+       if (ret < 0) {
+               WARN("Failed to create a userspace probe location from the received buffer");
                ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
                goto error;
        }
@@ -645,8 +661,8 @@ static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
                goto error;
        }
 
-       lttng_dynamic_buffer_reset(&probe_location_buffer);
 error:
+       lttng_payload_reset(&probe_location_payload);
        return ret;
 }
 
@@ -1739,32 +1755,34 @@ error_add_context:
        }
        case LTTNG_LIST_EVENTS:
        {
-               ssize_t nb_event;
-               struct lttng_event *events = NULL;
-               struct lttcomm_event_command_header cmd_header;
-               size_t total_size;
-
-               memset(&cmd_header, 0, sizeof(cmd_header));
-               /* Extended infos are included at the end of events */
-               nb_event = cmd_list_events(cmd_ctx->lsm.domain.type,
-                       cmd_ctx->session, cmd_ctx->lsm.u.list.channel_name,
-                       &events, &total_size);
-
-               if (nb_event < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_event;
-                       goto error;
+               ssize_t list_ret;
+               struct lttcomm_event_command_header cmd_header = {};
+               size_t original_payload_size;
+               size_t payload_size;
+
+               ret = setup_empty_lttng_msg(cmd_ctx);
+               if (ret) {
+                       ret = LTTNG_ERR_NOMEM;
+                       goto setup_error;
                }
 
-               cmd_header.nb_events = nb_event;
-               ret = setup_lttng_msg(cmd_ctx, events, total_size,
-                       &cmd_header, sizeof(cmd_header));
-               free(events);
+               original_payload_size = cmd_ctx->reply_payload.buffer.size;
 
-               if (ret < 0) {
-                       goto setup_error;
+               /* Extended infos are included at the end of the payload. */
+               list_ret = cmd_list_events(cmd_ctx->lsm.domain.type,
+                               cmd_ctx->session,
+                               cmd_ctx->lsm.u.list.channel_name,
+                               &cmd_ctx->reply_payload);
+               if (list_ret < 0) {
+                       /* Return value is a negative lttng_error_code. */
+                       ret = -list_ret;
+                       goto error;
                }
 
+               payload_size = cmd_ctx->reply_payload.buffer.size -
+                               sizeof(cmd_header) - original_payload_size;
+               update_lttng_msg(cmd_ctx, sizeof(cmd_header), payload_size);
+
                ret = LTTNG_OK;
                break;
        }
@@ -2250,6 +2268,7 @@ static void *thread_manage_clients(void *data)
                cmd_ctx.session = NULL;
                lttng_dynamic_buffer_set_size(&cmd_ctx.reply_payload.buffer, 0);
                lttng_dynamic_array_clear(&cmd_ctx.reply_payload._fds);
+               cmd_ctx.lttng_msg_size = 0;
 
                DBG("Accepting client command ...");
 
@@ -2384,13 +2403,15 @@ static void *thread_manage_clients(void *data)
                                        lttng_payload_view_from_payload(
                                                        &cmd_ctx.reply_payload,
                                                        0, -1);
-                       const struct lttcomm_lttng_msg *llm = (typeof(
+                       struct lttcomm_lttng_msg *llm = (typeof(
                                        llm)) cmd_ctx.reply_payload.buffer.data;
 
                        assert(cmd_ctx.reply_payload.buffer.size >=
                               sizeof(llm));
                        assert(cmd_ctx.lttng_msg_size == cmd_ctx.reply_payload.buffer.size);
 
+                       llm->fd_count = lttng_payload_view_get_fd_count(&view);
+
                        DBG("Sending response (size: %d, retcode: %s (%d))",
                                        cmd_ctx.lttng_msg_size,
                                        lttng_strerror(-llm->ret_code),
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