[Asterisk-code-review] res_rtp_asterisk: Add a DEVMODE RTP drop packets CLI command (asterisk[16])
George Joseph
asteriskteam at digium.com
Wed Mar 31 09:31:52 CDT 2021
George Joseph has submitted this change. ( https://gerrit.asterisk.org/c/asterisk/+/15592 )
Change subject: res_rtp_asterisk: Add a DEVMODE RTP drop packets CLI command
......................................................................
res_rtp_asterisk: Add a DEVMODE RTP drop packets CLI command
This patch makes it so when Asterisk is compiled in DEVMODE a CLI
command is available that allows someone to drop incoming RTP
packets. The command allows for dropping of packets once, or on a
timed interval (e.g. drop 10 packets every 5 seconds). A user can
also specify to drop packets by IP address.
Change-Id: I25fa7ae9bad6ed68e273bbcccf0ee51cae6e7024
---
M res/res_rtp_asterisk.c
1 file changed, 250 insertions(+), 0 deletions(-)
Approvals:
Joshua Colp: Looks good to me, but someone else must approve
George Joseph: Looks good to me, approved; Approved for Submit
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index b0a3f2a..ac01d39 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -63,6 +63,7 @@
#include <ifaddrs.h>
#endif
+#include "asterisk/conversions.h"
#include "asterisk/options.h"
#include "asterisk/logger_category.h"
#include "asterisk/stun.h"
@@ -7529,6 +7530,113 @@
return AST_LIST_FIRST(&frames);
}
+#ifdef AST_DEVMODE
+
+struct rtp_drop_packets_data {
+ /* Whether or not to randomize the number of packets to drop. */
+ unsigned int use_random_num;
+ /* Whether or not to randomize the time interval between packets drops. */
+ unsigned int use_random_interval;
+ /* The total number of packets to drop. If 'use_random_num' is true then this
+ * value becomes the upper bound for a number of random packets to drop. */
+ unsigned int num_to_drop;
+ /* The current number of packets that have been dropped during an interval. */
+ unsigned int num_dropped;
+ /* The optional interval to use between packet drops. If 'use_random_interval'
+ * is true then this values becomes the upper bound for a random interval used. */
+ struct timeval interval;
+ /* The next time a packet drop should be triggered. */
+ struct timeval next;
+ /* An optional IP address from which to drop packets from. */
+ struct ast_sockaddr addr;
+ /* The optional port from which to drop packets from. */
+ unsigned int port;
+} drop_packets_data;
+
+static void drop_packets_data_update(struct timeval tv)
+{
+ /*
+ * num_dropped keeps up with the number of packets that have been dropped for a
+ * given interval. Once the specified number of packets have been dropped and
+ * the next time interval is ready to trigger then set this number to zero (drop
+ * the next 'n' packets up to 'num_to_drop'), or if 'use_random_num' is set to
+ * true then set to a random number between zero and 'num_to_drop'.
+ */
+ drop_packets_data.num_dropped = drop_packets_data.use_random_num ?
+ ast_random() % drop_packets_data.num_to_drop : 0;
+
+ /*
+ * A specified number of packets can be dropped at a given interval (e.g every
+ * 30 seconds). If 'use_random_interval' is false simply add the interval to
+ * the given time to get the next trigger point. If set to true, then get a
+ * random time between the given time and up to the specified interval.
+ */
+ if (drop_packets_data.use_random_interval) {
+ /* Calculate as a percentage of the specified drop packets interval */
+ struct timeval interval = ast_time_create_by_unit(ast_time_tv_to_usec(
+ &drop_packets_data.interval) * ((double)(ast_random() % 100 + 1) / 100),
+ TIME_UNIT_MICROSECOND);
+
+ drop_packets_data.next = ast_tvadd(tv, interval);
+ } else {
+ drop_packets_data.next = ast_tvadd(tv, drop_packets_data.interval);
+ }
+}
+
+static int should_drop_packets(struct ast_sockaddr *addr)
+{
+ struct timeval tv;
+
+ if (!drop_packets_data.num_to_drop) {
+ return 0;
+ }
+
+ /*
+ * If an address has been specified then filter on it, and also the port if
+ * it too was included.
+ */
+ if (!ast_sockaddr_isnull(&drop_packets_data.addr) &&
+ (drop_packets_data.port ?
+ ast_sockaddr_cmp(&drop_packets_data.addr, addr) :
+ ast_sockaddr_cmp_addr(&drop_packets_data.addr, addr)) != 0) {
+ /* Address and/or port does not match */
+ return 0;
+ }
+
+ /* Keep dropping packets until we've reached the total to drop */
+ if (drop_packets_data.num_dropped < drop_packets_data.num_to_drop) {
+ ++drop_packets_data.num_dropped;
+ return 1;
+ }
+
+ /*
+ * Once the set number of packets has been dropped check to see if it's
+ * time to drop more.
+ */
+
+ if (ast_tvzero(drop_packets_data.interval)) {
+ /* If no interval then drop specified number of packets and be done */
+ drop_packets_data.num_to_drop = 0;
+ return 0;
+ }
+
+ tv = ast_tvnow();
+ if (ast_tvcmp(tv, drop_packets_data.next) == -1) {
+ /* Still waiting for the next time interval to elapse */
+ return 0;
+ }
+
+ /*
+ * The next time interval has elapsed so update the tracking structure
+ * in order to start dropping more packets, and figure out when the next
+ * time interval is.
+ */
+ drop_packets_data_update(tv);
+ return 1;
+}
+
+#endif
+
/*! \pre instance is locked */
static struct ast_frame *ast_rtp_read(struct ast_rtp_instance *instance, int rtcp)
{
@@ -7823,6 +7931,14 @@
seqno &= 0xffff;
timestamp = ntohl(rtpheader[1]);
+#ifdef AST_DEVMODE
+ if (should_drop_packets(&addr)) {
+ ast_debug(0, "(%p) RTP: drop received packet from %s (type %-2.2d, seq %-6.6u, ts %-6.6u, len %-6.6d)\n",
+ instance, ast_sockaddr_stringify(&addr), payloadtype, seqno, timestamp, res - hdrlen);
+ return &ast_null_frame;
+ }
+#endif
+
if (rtp_debug_test_addr(&addr)) {
ast_verbose("Got RTP packet from %s (type %-2.2d, seq %-6.6u, ts %-6.6u, len %-6.6d)\n",
ast_sockaddr_stringify(&addr),
@@ -9088,11 +9204,145 @@
return CLI_SUCCESS;
}
+#ifdef AST_DEVMODE
+
+static unsigned int use_random(struct ast_cli_args *a, int pos, unsigned int index)
+{
+ return pos >= index && !ast_strlen_zero(a->argv[index - 1]) &&
+ !strcasecmp(a->argv[index - 1], "random");
+}
+
+static char *handle_cli_rtp_drop_incoming_packets(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+ static const char * const completions_2[] = { "stop", "<N>", NULL };
+ static const char * const completions_3[] = { "random", "incoming packets", NULL };
+ static const char * const completions_5[] = { "on", "every", NULL };
+ static const char * const completions_units[] = { "random", "usec", "msec", "sec", "min", NULL };
+
+ unsigned int use_random_num = 0;
+ unsigned int use_random_interval = 0;
+ unsigned int num_to_drop = 0;
+ unsigned int interval = 0;
+ const char *interval_s = NULL;
+ const char *unit_s = NULL;
+ struct ast_sockaddr addr;
+ const char *addr_s = NULL;
+
+ switch (cmd) {
+ case CLI_INIT:
+ e->command = "rtp drop";
+ e->usage =
+ "Usage: rtp drop [stop|[<N> [random] incoming packets[ every <N> [random] {usec|msec|sec|min}][ on <ip[:port]>]]\n"
+ " Drop RTP incoming packets.\n";
+ return NULL;
+ case CLI_GENERATE:
+ use_random_num = use_random(a, a->pos, 4);
+ use_random_interval = use_random(a, a->pos, 8 + use_random_num) ||
+ use_random(a, a->pos, 10 + use_random_num);
+
+ switch (a->pos - use_random_num - use_random_interval) {
+ case 2:
+ return ast_cli_complete(a->word, completions_2, a->n);
+ case 3:
+ return ast_cli_complete(a->word, completions_3 + use_random_num, a->n);
+ case 5:
+ return ast_cli_complete(a->word, completions_5, a->n);
+ case 7:
+ if (!strcasecmp(a->argv[a->pos - 2], "on")) {
+ ast_cli_completion_add(ast_strdup("every"));
+ break;
+ }
+ /* Fall through */
+ case 9:
+ if (!strcasecmp(a->argv[a->pos - 2 - use_random_interval], "every")) {
+ return ast_cli_complete(a->word, completions_units + use_random_interval, a->n);
+ }
+ break;
+ case 8:
+ if (!strcasecmp(a->argv[a->pos - 3 - use_random_interval], "every")) {
+ ast_cli_completion_add(ast_strdup("on"));
+ }
+ break;
+ }
+
+ return NULL;
+ }
+
+ if (a->argc < 3) {
+ return CLI_SHOWUSAGE;
+ }
+
+ use_random_num = use_random(a, a->argc, 4);
+ use_random_interval = use_random(a, a->argc, 8 + use_random_num) ||
+ use_random(a, a->argc, 10 + use_random_num);
+
+ if (!strcasecmp(a->argv[2], "stop")) {
+ /* rtp drop stop */
+ } else if (a->argc < 5) {
+ return CLI_SHOWUSAGE;
+ } else if (ast_str_to_uint(a->argv[2], &num_to_drop)) {
+ ast_cli(a->fd, "%s is not a valid number of packets to drop\n", a->argv[2]);
+ return CLI_FAILURE;
+ } else if (a->argc - use_random_num == 5) {
+ /* rtp drop <N> [random] incoming packets */
+ } else if (a->argc - use_random_num >= 7 && !strcasecmp(a->argv[5 + use_random_num], "on")) {
+ /* rtp drop <N> [random] incoming packets on <ip[:port]> */
+ addr_s = a->argv[6 + use_random_num];
+ if (a->argc - use_random_num - use_random_interval == 10 &&
+ !strcasecmp(a->argv[7 + use_random_num], "every")) {
+ /* rtp drop <N> [random] incoming packets on <ip[:port]> every <N> [random] {usec|msec|sec|min} */
+ interval_s = a->argv[8 + use_random_num];
+ unit_s = a->argv[9 + use_random_num + use_random_interval];
+ }
+ } else if (a->argc - use_random_num >= 8 && !strcasecmp(a->argv[5 + use_random_num], "every")) {
+ /* rtp drop <N> [random] incoming packets every <N> [random] {usec|msec|sec|min} */
+ interval_s = a->argv[6 + use_random_num];
+ unit_s = a->argv[7 + use_random_num + use_random_interval];
+ if (a->argc == 10 + use_random_num + use_random_interval &&
+ !strcasecmp(a->argv[8 + use_random_num + use_random_interval], "on")) {
+ /* rtp drop <N> [random] incoming packets every <N> [random] {usec|msec|sec|min} on <ip[:port]> */
+ addr_s = a->argv[9 + use_random_num + use_random_interval];
+ }
+ } else {
+ return CLI_SHOWUSAGE;
+ }
+
+ if (a->argc - use_random_num >= 8 && !interval_s && !addr_s) {
+ return CLI_SHOWUSAGE;
+ }
+
+ if (interval_s && ast_str_to_uint(interval_s, &interval)) {
+ ast_cli(a->fd, "%s is not a valid interval number\n", interval_s);
+ return CLI_FAILURE;
+ }
+
+ memset(&addr, 0, sizeof(addr));
+ if (addr_s && !ast_sockaddr_parse(&addr, addr_s, 0)) {
+ ast_cli(a->fd, "%s is not a valid hostname[:port]\n", addr_s);
+ return CLI_FAILURE;
+ }
+
+ drop_packets_data.use_random_num = use_random_num;
+ drop_packets_data.use_random_interval = use_random_interval;
+ drop_packets_data.num_to_drop = num_to_drop;
+ drop_packets_data.interval = ast_time_create_by_unit_str(interval, unit_s);
+ ast_sockaddr_copy(&drop_packets_data.addr, &addr);
+ drop_packets_data.port = ast_sockaddr_port(&addr);
+
+ drop_packets_data_update(ast_tvnow());
+
+ return CLI_SUCCESS;
+}
+#endif
+
static struct ast_cli_entry cli_rtp[] = {
AST_CLI_DEFINE(handle_cli_rtp_set_debug, "Enable/Disable RTP debugging"),
AST_CLI_DEFINE(handle_cli_rtp_settings, "Display RTP settings"),
AST_CLI_DEFINE(handle_cli_rtcp_set_debug, "Enable/Disable RTCP debugging"),
AST_CLI_DEFINE(handle_cli_rtcp_set_stats, "Enable/Disable RTCP stats"),
+#ifdef AST_DEVMODE
+ AST_CLI_DEFINE(handle_cli_rtp_drop_incoming_packets, "Drop RTP incoming packets"),
+#endif
};
static int rtp_reload(int reload, int by_external_config)
--
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Gerrit-Project: asterisk
Gerrit-Branch: 16
Gerrit-Change-Id: I25fa7ae9bad6ed68e273bbcccf0ee51cae6e7024
Gerrit-Change-Number: 15592
Gerrit-PatchSet: 6
Gerrit-Owner: Kevin Harwell <kharwell at digium.com>
Gerrit-Reviewer: Benjamin Keith Ford <bford at digium.com>
Gerrit-Reviewer: Friendly Automation
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Joshua Colp <jcolp at sangoma.com>
Gerrit-Reviewer: Kevin Harwell <kharwell at digium.com>
Gerrit-MessageType: merged
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