Fix: liblttng-ctl comm: lttng_channel is not packed
[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl.cpp
index 3622987183c5db8c4bdf8e0f48b70b7bd63b5366..3e39b5b0cc216ad229b91bce5add89872cba24d2 100644 (file)
@@ -3,7 +3,7 @@
  *
  * Linux Trace Toolkit Control Library
  *
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 EfficiOS Inc.
  * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
  * SPDX-License-Identifier: LGPL-2.1-only
@@ -14,6 +14,7 @@
 #include <grp.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -47,7 +48,7 @@
 
 #include "lttng-ctl-helper.h"
 #include <common/filter/filter-ast.h>
-#include <common/filter/filter-parser.h>
+#include <common/filter/filter-parser.hpp>
 #include <common/filter/memstream.h>
 
 #define COPY_DOMAIN_PACKED(dst, src)                           \
@@ -290,12 +291,14 @@ end:
        return ret;
 }
 
-static int check_enough_available_memory(size_t num_bytes_requested_per_cpu)
+static enum lttng_error_code check_enough_available_memory(
+               uint64_t num_bytes_requested_per_cpu)
 {
        int ret;
+       enum lttng_error_code ret_code;
        long num_cpu;
-       size_t best_mem_info;
-       size_t num_bytes_requested_total;
+       uint64_t best_mem_info;
+       uint64_t num_bytes_requested_total;
 
        /*
         * Get the number of CPU currently online to compute the amount of
@@ -303,10 +306,18 @@ static int check_enough_available_memory(size_t num_bytes_requested_per_cpu)
         */
        num_cpu = sysconf(_SC_NPROCESSORS_ONLN);
        if (num_cpu == -1) {
-               goto error;
+               ret_code = LTTNG_ERR_FATAL;
+               goto end;
+       }
+
+       if (num_bytes_requested_per_cpu > UINT64_MAX / (uint64_t) num_cpu) {
+               /* Overflow */
+               ret_code = LTTNG_ERR_OVERFLOW;
+               goto end;
        }
 
-       num_bytes_requested_total = num_bytes_requested_per_cpu * num_cpu;
+       num_bytes_requested_total =
+                       num_bytes_requested_per_cpu * (uint64_t) num_cpu;
 
        /*
         * Try to get the `MemAvail` field of `/proc/meminfo`. This is the most
@@ -328,10 +339,18 @@ static int check_enough_available_memory(size_t num_bytes_requested_per_cpu)
                goto success;
        }
 
-error:
-       return -1;
+       /* No valid source of information. */
+       ret_code = LTTNG_ERR_NOMEM;
+       goto end;
+
 success:
-       return best_mem_info >= num_bytes_requested_total;
+       if (best_mem_info >= num_bytes_requested_total) {
+               ret_code = LTTNG_OK;
+       } else {
+               ret_code = LTTNG_ERR_NOMEM;
+       }
+end:
+       return ret_code;
 }
 
 /*
@@ -1515,10 +1534,9 @@ end:
 struct lttng_channel *lttng_channel_create(struct lttng_domain *domain)
 {
        struct lttng_channel *channel = NULL;
-       struct lttng_channel_extended *extended = NULL;
 
        if (!domain) {
-               goto error;
+               goto end;
        }
 
        /* Validate domain. */
@@ -1529,36 +1547,26 @@ struct lttng_channel *lttng_channel_create(struct lttng_domain *domain)
                case LTTNG_BUFFER_PER_PID:
                        break;
                default:
-                       goto error;
+                       goto end;
                }
                break;
        case LTTNG_DOMAIN_KERNEL:
                if (domain->buf_type != LTTNG_BUFFER_GLOBAL) {
-                       goto error;
+                       goto end;
                }
                break;
        default:
-               goto error;
+               goto end;
        }
 
-       channel = (lttng_channel *) zmalloc(sizeof(*channel));
+       channel = lttng_channel_create_internal();
        if (!channel) {
-               goto error;
-       }
-
-       extended = (lttng_channel_extended *) zmalloc(sizeof(*extended));
-       if (!extended) {
-               goto error;
+               goto end;
        }
 
-       channel->attr.extended.ptr = extended;
-
        lttng_channel_set_default_attr(domain, &channel->attr);
+end:
        return channel;
-error:
-       free(channel);
-       free(extended);
-       return NULL;
 }
 
 void lttng_channel_destroy(struct lttng_channel *channel)
@@ -1580,53 +1588,65 @@ void lttng_channel_destroy(struct lttng_channel *channel)
 int lttng_enable_channel(struct lttng_handle *handle,
                struct lttng_channel *in_chan)
 {
+       enum lttng_error_code ret_code;
        int ret;
+       struct lttng_dynamic_buffer buffer;
        struct lttcomm_session_msg lsm;
-       size_t total_buffer_size_needed_per_cpu = 0;
+       uint64_t total_buffer_size_needed_per_cpu = 0;
+       struct lttng_channel *channel = NULL;
+
+       lttng_dynamic_buffer_init(&buffer);
 
        /* NULL arguments are forbidden. No default values. */
        if (handle == NULL || in_chan == NULL) {
-               return -LTTNG_ERR_INVALID;
+               ret = -LTTNG_ERR_INVALID;
+               goto end;
        }
 
-       memset(&lsm, 0, sizeof(lsm));
-       memcpy(&lsm.u.channel.chan, in_chan, sizeof(lsm.u.channel.chan));
-       lsm.u.channel.chan.attr.extended.ptr = NULL;
+       /*
+        * Verify that the amount of memory required to create the requested
+        * buffer is available on the system at the moment.
+        */
+       if (in_chan->attr.num_subbuf >
+                       UINT64_MAX / in_chan->attr.subbuf_size) {
+               /* Overflow */
+               ret = -LTTNG_ERR_OVERFLOW;
+               goto end;
+       }
 
-       if (!in_chan->attr.extended.ptr) {
-               struct lttng_channel *channel;
-               struct lttng_channel_extended *extended;
+       total_buffer_size_needed_per_cpu =
+                       in_chan->attr.num_subbuf * in_chan->attr.subbuf_size;
+       ret_code = check_enough_available_memory(
+                       total_buffer_size_needed_per_cpu);
+       if (ret_code != LTTNG_OK) {
+               ret = -ret_code;
+               goto end;
+       }
 
-               channel = lttng_channel_create(&handle->domain);
-               if (!channel) {
-                       return -LTTNG_ERR_NOMEM;
-               }
+       /* Copy the channel for easier manipulation. */
+       channel = lttng_channel_copy(in_chan);
+       if (!channel) {
+               ret = -LTTNG_ERR_NOMEM;
+               goto end;
+       }
 
-               /*
-                * Create a new channel in order to use default extended
-                * attribute values.
-                */
-               extended = (struct lttng_channel_extended *)
-                               channel->attr.extended.ptr;
-               memcpy(&lsm.u.channel.extended, extended, sizeof(*extended));
-               lttng_channel_destroy(channel);
-       } else {
-               struct lttng_channel_extended *extended;
+       /* Populate the channel extended attribute if necessary. */
+       if (!channel->attr.extended.ptr) {
+               struct lttng_channel_extended *extended =
+                               (struct lttng_channel_extended *) zmalloc(
+                                               sizeof(*extended));
 
-               extended = (struct lttng_channel_extended *)
-                               in_chan->attr.extended.ptr;
-               memcpy(&lsm.u.channel.extended, extended, sizeof(*extended));
+               if (!extended) {
+                       ret = -LTTNG_ERR_NOMEM;
+                       goto end;
+               }
+               lttng_channel_set_default_extended_attr(
+                               &handle->domain, extended);
+               channel->attr.extended.ptr = extended;
        }
 
-       /*
-        * Verify that the amount of memory required to create the requested
-        * buffer is available on the system at the moment.
-        */
-       total_buffer_size_needed_per_cpu = lsm.u.channel.chan.attr.num_subbuf *
-               lsm.u.channel.chan.attr.subbuf_size;
-       if (!check_enough_available_memory(total_buffer_size_needed_per_cpu)) {
-               return -LTTNG_ERR_NOMEM;
-       }
+       /* Prepare the payload */
+       memset(&lsm, 0, sizeof(lsm));
 
        lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
        COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
@@ -1638,8 +1658,19 @@ int lttng_enable_channel(struct lttng_handle *handle,
                goto end;
        }
 
-       ret = lttng_ctl_ask_sessiond(&lsm, NULL);
+       ret = lttng_channel_serialize(channel, &buffer);
+       if (ret) {
+               ret = -LTTNG_ERR_FATAL;
+               goto end;
+       }
+
+       lsm.u.channel.length = buffer.size;
+
+       ret = lttng_ctl_ask_sessiond_varlen_no_cmd_header(
+                       &lsm, buffer.data, buffer.size, NULL);
 end:
+       lttng_channel_destroy(channel);
+       lttng_dynamic_buffer_reset(&buffer);
        return ret;
 }
 
@@ -1769,10 +1800,14 @@ int lttng_list_syscalls(struct lttng_event **events)
 
 /*
  * Returns a human readable string describing
- * the error code (a negative value).
+ * the error code (positive or negative value).
  */
 const char *lttng_strerror(int code)
 {
+       if (code > 0) {
+               code = -code;
+       }
+
        return error_get_str(code);
 }
 
@@ -2098,6 +2133,12 @@ int lttng_list_sessions(struct lttng_session **out_sessions)
 
        memset(&lsm, 0, sizeof(lsm));
        lsm.cmd_type = LTTNG_LIST_SESSIONS;
+       /*
+        * Initialize out_sessions to NULL so it is initialized when
+        * lttng_list_sessions returns 0, thus allowing *out_sessions to
+        * be subsequently freed.
+        */
+       *out_sessions = NULL;
        ret = lttng_ctl_ask_sessiond(&lsm, (void**) &sessions);
        if (ret <= 0) {
                goto end;
@@ -2110,7 +2151,6 @@ int lttng_list_sessions(struct lttng_session **out_sessions)
        if (ret % session_size) {
                ret = -LTTNG_ERR_UNK;
                free(sessions);
-               *out_sessions = NULL;
                goto end;
        }
        session_count = (size_t) ret / session_size;
@@ -2232,12 +2272,14 @@ error:
 int lttng_list_channels(struct lttng_handle *handle,
                struct lttng_channel **channels)
 {
-       int ret;
-       size_t channel_count, i;
-       const size_t channel_size = sizeof(struct lttng_channel) +
-                       sizeof(struct lttng_channel_extended);
+       int ret, total_payload_received;
        struct lttcomm_session_msg lsm;
-       char *extended_at;
+       char *reception_buffer = NULL;
+       size_t cmd_header_len = 0;
+       struct lttcomm_list_command_header *cmd_header = NULL;
+       struct lttng_dynamic_buffer tmp_buffer;
+
+       lttng_dynamic_buffer_init(&tmp_buffer);
 
        if (handle == NULL) {
                ret = -LTTNG_ERR_INVALID;
@@ -2255,31 +2297,48 @@ int lttng_list_channels(struct lttng_handle *handle,
 
        COPY_DOMAIN_PACKED(lsm.domain, handle->domain);
 
-       ret = lttng_ctl_ask_sessiond(&lsm, (void**) channels);
+       ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+                       (void **) &reception_buffer, (void **) &cmd_header,
+                       &cmd_header_len);
        if (ret < 0) {
                goto end;
        }
 
-       if (ret % channel_size) {
-               ret = -LTTNG_ERR_UNK;
-               free(*channels);
-               *channels = NULL;
+       total_payload_received = ret;
+
+       if (cmd_header_len != sizeof(*cmd_header)) {
+               ret = -LTTNG_ERR_FATAL;
+               goto end;
+       }
+
+       if (!cmd_header) {
+               ret = LTTNG_ERR_UNK;
                goto end;
        }
-       channel_count = (size_t) ret / channel_size;
 
-       /* Set extended info pointers */
-       extended_at = ((char *) *channels) +
-                       channel_count * sizeof(struct lttng_channel);
-       for (i = 0; i < channel_count; i++) {
-               struct lttng_channel *chan = &(*channels)[i];
+       if (cmd_header->count > INT_MAX) {
+               ret = -LTTNG_ERR_OVERFLOW;
+               goto end;
+       }
 
-               chan->attr.extended.ptr = extended_at;
-               extended_at += sizeof(struct lttng_channel_extended);
+       {
+               enum lttng_error_code ret_code;
+               const struct lttng_buffer_view events_view =
+                               lttng_buffer_view_init(reception_buffer, 0,
+                                               total_payload_received);
+
+               ret_code = lttng_channels_create_and_flatten_from_buffer(
+                               &events_view, cmd_header->count, channels);
+               if (ret_code != LTTNG_OK) {
+                       ret = -ret_code;
+                       goto end;
+               }
        }
 
-       ret = (int) channel_count;
+       ret = (int) cmd_header->count;
 end:
+       free(cmd_header);
+       free(reception_buffer);
        return ret;
 }
 
@@ -2659,6 +2718,7 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
                return;
        }
 
+       /* Save the pointer for later use */
        extended = (struct lttng_channel_extended *) attr->extended.ptr;
        memset(attr, 0, sizeof(struct lttng_channel_attr));
 
@@ -2675,12 +2735,6 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
                attr->subbuf_size = default_get_kernel_channel_subbuf_size();
                attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
                attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
-               if (extended) {
-                       extended->monitor_timer_interval =
-                                       DEFAULT_KERNEL_CHANNEL_MONITOR_TIMER;
-                       extended->blocking_timeout =
-                                       DEFAULT_KERNEL_CHANNEL_BLOCKING_TIMEOUT;
-               }
                break;
        case LTTNG_DOMAIN_UST:
                switch (domain->buf_type) {
@@ -2692,12 +2746,6 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
                                        DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
                        attr->read_timer_interval =
                                        DEFAULT_UST_UID_CHANNEL_READ_TIMER;
-                       if (extended) {
-                               extended->monitor_timer_interval =
-                                               DEFAULT_UST_UID_CHANNEL_MONITOR_TIMER;
-                               extended->blocking_timeout =
-                                               DEFAULT_UST_UID_CHANNEL_BLOCKING_TIMEOUT;
-                       }
                        break;
                case LTTNG_BUFFER_PER_PID:
                default:
@@ -2708,12 +2756,6 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
                                        DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
                        attr->read_timer_interval =
                                        DEFAULT_UST_PID_CHANNEL_READ_TIMER;
-                       if (extended) {
-                               extended->monitor_timer_interval =
-                                               DEFAULT_UST_PID_CHANNEL_MONITOR_TIMER;
-                               extended->blocking_timeout =
-                                               DEFAULT_UST_PID_CHANNEL_BLOCKING_TIMEOUT;
-                       }
                        break;
                }
        default:
@@ -2721,6 +2763,11 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
                break;
        }
 
+       if (extended) {
+               lttng_channel_set_default_extended_attr(domain, extended);
+       }
+
+       /* Reassign the extended pointer. */
        attr->extended.ptr = extended;
 }
 
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