[lttng-dev] [PATCH lttng-tools v5 1/2] lttng-relayd: use TCP keep-alive mechanism to detect dead-peer
Jérémie Galarneau
jeremie.galarneau at efficios.com
Thu Feb 1 23:03:13 UTC 2018
Merged with some changes.
Thanks!
Jérémie
On 22 January 2018 at 15:43, Jonathan Rajotte
<jonathan.rajotte-julien at efficios.com> wrote:
> Allow relayd to clean-up objects related to a dead connection
> for which the FIN packet was no emitted (Unexpected shutdown,
> ethernet:blocking). Note that an idle peer is not considered dead given
> that it respond to the keep-alive query after the idle time is elapsed.
>
> By RFC 1122-4.2.3.6 implementation must default to no less than two
> hours for the idle period. On linux the default value is indeed 2 hours.
> This could be problematic if relayd should be aggressive regarding
> dead-peers. Hence it is important to provide tuning knob regarding the
> tcp keep-alive mechanism.
>
> The following environments variable can be used to enable and fine-tune
> it:
> LTTNG_RELAYD_TCP_KEEP_ALIVE_ENABLE
> Set to 1 to enable the use of tcp keep-alive allowing the detection
> of dead peers.
>
> LTTNG_RELAYD_TCP_KEEP_ALIVE_TIME
> See tcp(7) tcp_keepalive_time or tcp_keepalive_interval on
> Solaris 11.
> A value of -1 lets the operating system manage this parameter
> (default).
>
> LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBES
> See tcp(7) tcp_keepalive_probes.
> A value of -1 lets the operating system manage this
> parameter (default).
> No effect on Solaris.
>
> LTTNG_RELAYD_TCP_KEEP_ALIVE_INTVL`::
> See tcp(7) tcp_keepalive_intvl.
> A value of -1 lets the operating system manage
> his parameter (default).
>
> Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> ---
> v5:
> - Move patch version information under signed-off.
> - Cleanup whitespace in commit msg.
>
> v4:
> - Complete rework to expose an internal API for TCP keep-alive
> functionality support.
> - keepalive -> keep_alive
> - Moved env. variables #define to defaults.h.
> - Introduced struct tcp_keep_alive_support and struct
> tcp_keep_alive_config as suggested.
> - Use config_parse_value for LTTNG_RELAYD_KEEP_ALIVE.
> Values supported: on,off,true,false,yes,no,1,0.
> - Support tcp_keepalive_abort_threshold on Solaris 11.
> This is the more granular equivalent to tcp_keepalive_probe &
> tcp_keepalive_intvl. The environment variable exposed is
> LTTNG_TCP_KEEP_ALIVE_ABORT_THRESHOLD.
> - tcp_keep_alive_init is called at lttng-relayd start to validate
> the values passed, if any, and error out if not they are not valid. It
> could be called lazily as proposed but would result in validation only
> when a socket is prepared (on channel creation) which is
> counter-intuitive and could happen a long time after lttng-relatd
> start.
> - tcp_keepalive_setsockopt renamed to socket_apply_keep_alive_config
>
> v3:
> - Fix inversion of definition for tcp_keepalive_time_valid.
> - Handle value of -1 and value < -1 in tcp_keepalive_time_valid
> - Allow value of -1 for LTTNG_RELAYD_TCP_KEEP_ALIVE_TIME,
> LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBES, LTTNG_RELAYD_TCP_KEEP_ALIVE_INTVL
> on Solaris 10 & 11.
> - Fix LTTNG_RELAYD_TCP_KEEP_ALIVE_TIME=-1 cases for solaris which would
> yield -1000 as final modifier value.
>
> v2:
> - Replace __sun -> __sun__
> - Use MS_PER_SEC
> - Modified definition of tcp_keepalive_time_valid to increase
> readability.
> - In tcp_keepalive_time_valid return true if value is -1 since it is
> equivalent to letting the system manage the setting.
> - Removed debugging getsockopt calls
> ---
> src/bin/lttng-relayd/Makefile.am | 3 +-
> src/bin/lttng-relayd/main.c | 15 +
> src/bin/lttng-relayd/tcp_keep_alive.c | 560 ++++++++++++++++++++++++++++++++++
> src/bin/lttng-relayd/tcp_keep_alive.h | 24 ++
> src/common/defaults.h | 7 +
> 5 files changed, 608 insertions(+), 1 deletion(-)
> create mode 100644 src/bin/lttng-relayd/tcp_keep_alive.c
> create mode 100644 src/bin/lttng-relayd/tcp_keep_alive.h
>
> diff --git a/src/bin/lttng-relayd/Makefile.am b/src/bin/lttng-relayd/Makefile.am
> index c7dd37e..5125c72 100644
> --- a/src/bin/lttng-relayd/Makefile.am
> +++ b/src/bin/lttng-relayd/Makefile.am
> @@ -21,7 +21,8 @@ lttng_relayd_SOURCES = main.c lttng-relayd.h utils.h utils.c cmd.h \
> stream-fd.c stream-fd.h \
> connection.c connection.h \
> viewer-session.c viewer-session.h \
> - tracefile-array.c tracefile-array.h
> + tracefile-array.c tracefile-array.h \
> + tcp_keep_alive.c tcp_keep_alive.h
>
> # link on liblttngctl for check if relayd is already alive.
> lttng_relayd_LDADD = -lurcu-common -lurcu \
> diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
> index 0eb8e28..b4f9457 100644
> --- a/src/bin/lttng-relayd/main.c
> +++ b/src/bin/lttng-relayd/main.c
> @@ -70,6 +70,7 @@
> #include "stream.h"
> #include "connection.h"
> #include "tracefile-array.h"
> +#include "tcp_keep_alive.h"
>
> static const char *help_msg =
> #ifdef LTTNG_EMBED_HELP
> @@ -899,6 +900,14 @@ restart:
> lttcomm_destroy_sock(newsock);
> goto error;
> }
> +
> + ret = socket_apply_keep_alive_config(newsock->fd);
> + if (ret < 0) {
> + PERROR("setsockopt tcp_keep_alive");
> + lttcomm_destroy_sock(newsock);
> + goto error;
> + }
> +
> new_conn = connection_create(newsock, type);
> if (!new_conn) {
> lttcomm_destroy_sock(newsock);
> @@ -2755,6 +2764,12 @@ int main(int argc, char **argv)
> goto exit_options;
> }
>
> +
> + if(tcp_keep_alive_init()){
> + retval = -1;
> + goto exit_options;
> + }
> +
> if (set_signal_handler()) {
> retval = -1;
> goto exit_options;
> diff --git a/src/bin/lttng-relayd/tcp_keep_alive.c b/src/bin/lttng-relayd/tcp_keep_alive.c
> new file mode 100644
> index 0000000..e22f4a9
> --- /dev/null
> +++ b/src/bin/lttng-relayd/tcp_keep_alive.c
> @@ -0,0 +1,560 @@
> +/*
> + * Copyright (C) 2017 - Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2 only,
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#include <sys/types.h>
> +#include <netinet/tcp.h>
> +#include <stdbool.h>
> +#include <sys/socket.h>
> +#include <limits.h>
> +
> +#include <common/compat/getenv.h>
> +#include <common/time.h>
> +#include <common/defaults.h>
> +#include <common/config/session-config.h>
> +
> +#include "tcp_keep_alive.h"
> +
> +#define SOLARIS_IDLE_TIME_MIN_S 10
> +#define SOLARIS_IDLE_TIME_MAX_S 864000 /* 10 days */
> +#define SOLARIS_ABORT_THRESHOLD_MIN_S 1
> +#define SOLARIS_ABORT_THRESHOLD_MAX_S 480 /* 8 minutes */
> +
> +/* Per-platform definition of TCP socket option */
> +#if defined (__linux__)
> +#define COMPAT_SOCKET_LEVEL SOL_TCP
> +#define COMPAT_TCP_LEVEL SOL_TCP
> +#define COMPAT_TCP_ABORT_THRESHOLD 0 /* Does not exists on linux */
> +#define COMPAT_TCP_KEEPIDLE TCP_KEEPIDLE
> +#define COMPAT_TCP_KEEPINTVL TCP_KEEPINTVL
> +#define COMPAT_TCP_KEEPCNT TCP_KEEPCNT
> +
> +#elif defined (__sun__) /* ! defined (__linux__) */
> +#define COMPAT_SOCKET_LEVEL SOL_SOCKET
> +#define COMPAT_TCP_LEVEL IPPROTO_TCP
> +
> +#ifdef TCP_KEEPALIVE_THRESHOLD
> +#define COMPAT_TCP_KEEPIDLE TCP_KEEPALIVE_THRESHOLD
> +#else /* ! defined (TCP_KEEPALIVE_THRESHOLD) */
> +#define COMPAT_TCP_KEEPIDLE 0
> +#endif /* TCP_KEEPALIVE_THRESHOLD */
> +
> +#ifdef TCP_KEEPALIVE_ABORT_THRESHOLD
> +#define COMPAT_TCP_ABORT_THRESHOLD TCP_KEEPALIVE_ABORT_THRESHOLD
> +#else /* ! defined (TCP_KEEPALIVE_ABORT_THRESHOLD) */
> +#define COMPAT_TCP_ABORT_THRESHOLD 0
> +#endif /* TCP_KEEPALIVE_ABORT_THRESHOLD */
> +
> +#define COMPAT_TCP_KEEPINTVL 0 /* Does not exists on sun */
> +#define COMPAT_TCP_KEEPCNT 0 /* Does not exists on sun */
> +
> +#else /* ! defined (__linux__) && ! defined (__sun__) */
> +#define COMPAT_SOCKET_LEVEL 0
> +#define COMPAT_TCP_LEVEL 0
> +#define COMPAT_TCP_ABORT_THRESHOLD 0
> +#define COMPAT_TCP_KEEPIDLE 0
> +#define COMPAT_TCP_KEEPINTVL 0
> +#define COMPAT_TCP_KEEPCNT 0
> +#endif /* ! defined (__linux__) && ! defined (__sun__) */
> +
> +struct tcp_keep_alive_support {
> + /* TCP keep-alive is supported by this platform. */
> + bool supported;
> + /* Overriding idle-time per socket is supported by this
> + * platform.
> + */
> + bool idle_time_supported;
> + /* Overriding probe interval per socket is supported by this
> + * platform.
> + */
> + bool probe_interval_supported;
> + /* Configuring max probe count per socket is supported by this
> + * platform.
> + */
> + bool max_probe_count_supported;
> + /* Overriding per socket is supported by this
> + * platform. Solaris specific
> + */
> + bool abort_threshold_supported;
> +};
> +
> +struct tcp_keep_alive_config {
> + bool initialized;
> + /* Maps to the environment variable defined
> + * by LTTNG_RELAYD_TCP_KEEP_ALIVE_ENV
> + */
> + bool enabled;
> + /* Maps to the environment variable defined
> + * by LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV
> + */
> + int idle_time;
> + /* Maps to the environment variable defined
> + * by LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV
> + */
> + int probe_interval;
> + /* Maps to the environment variable defined
> + * by LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV
> + */
> + int max_probe_count;
> + /* Maps to the environment variable defined
> + * by LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV
> + */
> + int abort_threshold;
> +};
> +
> +static struct tcp_keep_alive_config config = {
> + .initialized = false,
> + .enabled = false,
> + .idle_time = -1,
> + .probe_interval = -1,
> + .max_probe_count = -1,
> + .abort_threshold = -1
> +};
> +
> +static struct tcp_keep_alive_support support = {
> + .supported = false,
> + .idle_time_supported = false,
> + .probe_interval_supported = false,
> + .max_probe_count_supported = false,
> + .abort_threshold_supported = false
> +};
> +
> +/*
> + * Common parser for string to positive int conversion where the value must be
> + * in range [-1, INT_MAX].
> + * Returns -2 on invalid value.
> + */
> +static
> +int tcp_keep_alive_string_to_pos_int_parser(const char *env_var, const char *value)
> +{
> + int ret;
> + long tmp;
> + char *endptr = NULL;
> +
> + errno = 0;
> + tmp = strtol(value, &endptr, 0);
> + if (errno != 0) {
> + ERR("%s cannot be parsed.", env_var);
> + PERROR("Errno for previous parsing failure.");
> + ret = -2;
> + goto end;
> + }
> +
> + if (endptr == value || *endptr != '\0') {
> + ERR("%s is not a valid number.", env_var);
> + ret = -1;
> + goto end;
> + }
> +
> + if (tmp < -1) {
> + ERR("%s must be greater or equal to -1.", env_var);
> + ret = -2;
> + goto end;
> + }
> + if (tmp > INT_MAX){
> + ERR("%s is too big. Maximum value is %d.", env_var, INT_MAX);
> + ret = -2;
> + goto end;
> + }
> +
> + ret = (int) tmp;
> +end:
> + return ret;
> +
> +}
> +
> +/*
> + * Per-platform implementation of tcp_keep_alive_idle_time_modifier.
> + * Returns -2 on invalid value.
> + */
> +#ifdef __sun__
> +static int tcp_keep_alive_idle_time_modifier(int value)
> +{
> + int ret;
> + unsigned int tmp_ms;
> +
> + if (value == -1 || value == 0) {
> + /* Use system defaults */
> + ret = value;
> + goto end;
> + }
> +
> + /*
> + * Additional constraints for Solaris 11.
> + * Minimum 10s, maximum 10 days. Defined by
> + * https://docs.oracle.com/cd/E23824_01/html/821-1475/tcp-7p.html#REFMAN7tcp-7p
> + */
> + if ((value < SOLARIS_IDLE_TIME_MIN_S || value > SOLARIS_IDLE_TIME_MAX_S)) {
> + ERR("%s must be comprised between %d and %d inclusively on Solaris.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV,
> + SOLARIS_IDLE_TIME_MIN_S,
> + SOLARIS_IDLE_TIME_MAX_S);
> + ret = -2;
> + goto end;
> + }
> +
> + /* On Solaris idle time is given in milliseconds. */
> + tmp_ms = (unsigned int) value * MSEC_PER_SEC;
> + if ((value != 0 && (tmp_ms / (unsigned int) value) != MSEC_PER_SEC ) || tmp_ms > INT_MAX){
> + /* Overflow */
> + int max_possible_value = INT_MAX / MSEC_PER_SEC;
> + ERR("%s is too big. Maximum value is %d.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV,
> + max_possible_value);
> + ret = -2;
> + goto end;
> + }
> +
> + /* tmp_ms is > 0 and <= INT_MAX. Cast is safe */
> + ret = (int) tmp_ms;
> +end:
> + return ret;
> +}
> +#else /* ! defined(__sun__) */
> +static int tcp_keep_alive_idle_time_modifier(int value)
> +{
> + return value;
> +}
> +#endif /* ! defined(__sun__) */
> +
> +/* Per-platform support of tcp_keep_alive functionality. */
> +#if defined (__linux__)
> +static
> +void tcp_keep_alive_init_support(struct tcp_keep_alive_support *support)
> +{
> + support->supported = true;
> + support->idle_time_supported = true;
> + support->probe_interval_supported = true;
> + support->max_probe_count_supported = true;
> + /* Solaris specific */
> + support->abort_threshold_supported = false;
> +}
> +#elif defined(__sun__) /* ! defined (__linux__) */
> +static
> +void tcp_keep_alive_init_support(struct tcp_keep_alive_support *support)
> +{
> + support->supported = true;
> +#ifdef TCP_KEEPALIVE_THRESHOLD
> + support->idle_time_supported = true;
> +#else
> + support->idle_time_supported = false;;
> +#endif /* TCP_KEEPALIVE_THRESHOLD */
> +
> + /* Sun does not support either tcp_keepalive_probes or
> + * tcp_keepalive_intvl. Inferring a value for
> + * TCP_KEEP_ALIVE_ABORT_THRESHOLD doing
> + * tcp_keepalive_probes * tcp_keepalive_intvl could yield a good
> + * alternative but Solaris does not detail the algorithm used (constant
> + * time retry like linux or something fancier). Ignore those
> + * settings on Solaris 11. We prefer to expose an environment
> + * variable only used on Sun for the abort threshold.
> + */
> + support->probe_interval_supported = false;
> + support->max_probe_count_supported = false;
> +#ifdef TCP_KEEPALIVE_ABORT_THRESHOLD
> + support->abort_threshold_supported = true;
> +#else
> + support->abort_threshold_supported = false;
> +#endif /* TCP_KEEPALIVE_THRESHOLD */
> +}
> +#else /* ! defined(__sun__) && ! defined(__linux__) */
> +/* Not supported */
> +static
> +void tcp_keep_alive_init_support(struct tcp_keep_alive_support *support)
> +{
> + support->supported = false;
> + support->idle_time_supported = false;
> + support->probe_interval_supported = false;
> + support->max_probe_count_supported = false;
> + support->abort_threshold_supported = false;
> +}
> +#endif /* ! defined(__sun__) && ! defined(__linux__) */
> +
> +#ifdef __sun__
> +/*
> + * Sun specific modifier for abort threshold.
> + * Return -2 on error.
> + * */
> +static int tcp_keep_alive_abort_threshold_modifier(int value)
> +{
> + int ret;
> + unsigned int tmp_ms;
> +
> + if (value == -1) {
> + /* Use system defaults */
> + ret = value;
> + goto end;
> + }
> +
> + /*
> + * Additional constraints for Solaris 11.
> + * Between 0 and 8 minutes.
> + * https://docs.oracle.com/cd/E19120-01/open.solaris/819-2724/fsvdh/index.html
> + * Restrict from 1 seconds to 8 minutes sice the 0 value goes against
> + * the purpose of dead peers detection by never timing out when probing.
> + * It does NOT mean that the connection timeout immediately.
> + * (Make no sense but was tested, validated and match the doc).
> + */
> + if ((value < SOLARIS_ABORT_THRESHOLD_MIN_S || value > SOLARIS_ABORT_THRESHOLD_MAX_S)) {
> + ERR("%s must be comprised between %d and %d inclusively on Solaris.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV,
> + SOLARIS_ABORT_THRESHOLD_MIN_S,
> + SOLARIS_ABORT_THRESHOLD_MAX_S);
> + ret = -2;
> + goto end;
> + }
> +
> + /* Abort threshold is given in milliseconds. */
> + tmp_ms = (unsigned int) value * MSEC_PER_SEC;
> + if ((value != 0 && (tmp_ms / (unsigned int) value) != MSEC_PER_SEC ) || tmp_ms > INT_MAX){
> + /* Overflow */
> + int max_possible_value = INT_MAX / MSEC_PER_SEC;
> + ERR("%s is too big. Maximum value is %d.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV,
> + max_possible_value);
> + ret = -2;
> + goto end;
> + }
> +
> + /* tmp_ms is > 0 and <= INT_MAX. Cast is safe */
> + ret = (int) tmp_ms;
> +end:
> + return ret;
> +}
> +#else
> +static int tcp_keep_alive_abort_threshold_modifier(int value)
> +{
> + return value;
> +}
> +#endif /* defined (__sun__) */
> +
> +
> +
> +/* Retrieve settings from env vars and check/warn if supported by platform. */
> +static
> +int tcp_keep_alive_init_config(struct tcp_keep_alive_support *support, struct tcp_keep_alive_config *config)
> +{
> + int ret;
> + const char *value;
> +
> + /* config is already defined with default value */
> + config->initialized = true;
> +
> + value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ENV);
> + if (!support->supported) {
> + if (value) {
> + WARN("Using per-socket TCP Keep-alive mechanism is not supported by this platform. Ignoring the %s environment variable.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ENV);
> + }
> + config->enabled = false;
> + } else if (value) {
> + ret = config_parse_value(value);
> + if (ret < 0 || ret > 1) {
> + ERR("Invalid value for %s", DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ENV);
> + ret = 1;
> + goto error;
> + }
> + config->enabled = ret;
> + }
> + DBG("TCP keep-alive mechanism %s", config->enabled ? "enabled": "disabled");
> +
> + /* Get value for tcp_keepalive_time in seconds*/
> + value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV);
> + if (!support->idle_time_supported) {
> + if (value) {
> + WARN("Overriding the TCP keep-alive idle time threshold per-socket is not supported by this platform. Ignoring the %s environment variable.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV);
> + }
> + config->idle_time = -1;
> + } else if (value) {
> + int idle_time_platform;
> + int idle_time_seconds;;
> + idle_time_seconds = tcp_keep_alive_string_to_pos_int_parser(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV, value);
> + if (idle_time_seconds < -1) {
> + ret = 1;
> + goto error;
> + }
> +
> + idle_time_platform = tcp_keep_alive_idle_time_modifier(idle_time_seconds);
> + if (idle_time_platform < -1) {
> + ret = 1;
> + goto error;
> + }
> +
> + config->idle_time = idle_time_platform;
> + DBG("Overriding %s to %d",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV,
> + idle_time_seconds);
> + }
> +
> + /* Get value for tcp_keepalive_intvl in seconds */
> + value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV);
> + if (!support->probe_interval_supported) {
> + if (value) {
> + WARN("Overriding the TCP keep-alive probe interval time per-socket is not supported by this platform. Ignoring the %s environment variable.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV);
> + }
> + config->probe_interval=-1;
> + } else if (value) {
> + int probe_interval;
> + probe_interval = tcp_keep_alive_string_to_pos_int_parser(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV, value);
> + if (probe_interval < -1) {
> + ret = 1;
> + goto error;
> + }
> + config->probe_interval = probe_interval;
> + DBG("Overriding %s to %d",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV,
> + config->probe_interval);
> + }
> +
> + /* Get value for tcp_keepalive_probes */
> + value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV);
> + if (!support->max_probe_count_supported) {
> + if (value) {
> + WARN("Overriding the TCP keep-alive maximum probe count per-socket is not supported by this platform. Ignoring the %s environment variable.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV);
> + }
> + config->max_probe_count = -1;
> + } else if (value) {
> + int max_probe_count;
> + max_probe_count = tcp_keep_alive_string_to_pos_int_parser(
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV,
> + value);
> + if (max_probe_count < -1) {
> + ret = 1;
> + goto error;
> + }
> + config->max_probe_count = max_probe_count;
> + DBG("Overriding %s to %d",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV,
> + config->max_probe_count);
> + }
> +
> + /* Get value for tcp_keepalive_abort_interval*/
> + value = lttng_secure_getenv(DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV);
> + if (!support->abort_threshold_supported) {
> + if (value) {
> + WARN("Overriding the TCP keep-alive abort threshold per-socket is not supported by this platform. Ignoring the %s environment variable.",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV);
> + }
> + config->abort_threshold = -1;
> + } else if (value) {
> + int abort_threshold_platform;
> + int abort_threshold_seconds;
> +
> + abort_threshold_seconds = tcp_keep_alive_string_to_pos_int_parser(
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV,
> + value);
> + if (abort_threshold_seconds < -1) {
> + ret = 1;
> + goto error;
> + }
> +
> + abort_threshold_platform = tcp_keep_alive_abort_threshold_modifier(abort_threshold_seconds);
> + if (abort_threshold_platform < -1) {
> + ret = 1;
> + goto error;
> + }
> +
> + config->abort_threshold = abort_threshold_platform;
> + DBG("Overriding %s to %d",
> + DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV,
> + config->abort_threshold);
> + }
> +
> + ret = 0;
> +
> +error:
> + return ret;
> +}
> +
> +/*
> + * Initialize the TCP keep-alive settings.
> + */
> +int tcp_keep_alive_init(void)
> +{
> + tcp_keep_alive_init_support(&support);
> + return tcp_keep_alive_init_config(&support, &config);
> +}
> +
> +/*
> + * Set the socket options regarding TCP keep-alive.
> + */
> +int socket_apply_keep_alive_config(int socket_fd)
> +{
> + int ret;
> + int val = 1;
> +
> + if (!config.initialized) {
> + ERR("TCP keep-alive configuration is not initialized.");
> + abort();
> + }
> +
> + /* TCP keep-alive */
> + if (!support.supported || !config.enabled ) {
> + ret = 0;
> + goto end;
> + }
> +
> + ret = setsockopt(socket_fd, COMPAT_SOCKET_LEVEL, SO_KEEPALIVE, &val,
> + sizeof(val));
> + if (ret < 0) {
> + PERROR("setsockopt so_keepalive");
> + goto end;
> + }
> +
> + /* TCP keep-alive idle time */
> + if (support.idle_time_supported && config.idle_time > 0) {
> + ret = setsockopt(socket_fd, COMPAT_TCP_LEVEL, COMPAT_TCP_KEEPIDLE, &config.idle_time,
> + sizeof(config.idle_time));
> + if (ret < 0) {
> + PERROR("setsockopt TCP_KEEPIDLE");
> + goto end;
> + }
> + }
> + /* TCP keep-alive probe interval */
> + if (support.probe_interval_supported && config.probe_interval > 0) {
> + ret = setsockopt(socket_fd, COMPAT_TCP_LEVEL, COMPAT_TCP_KEEPINTVL, &config.probe_interval,
> + sizeof(config.probe_interval));
> + if (ret < 0) {
> + PERROR("setsockopt TCP_KEEPINTVL");
> + goto end;
> + }
> + }
> +
> + /* TCP keep-alive max probe count */
> + if (support.max_probe_count_supported && config.max_probe_count > 0) {
> + ret = setsockopt(socket_fd, COMPAT_TCP_LEVEL, COMPAT_TCP_KEEPCNT, &config.max_probe_count,
> + sizeof(config.max_probe_count));
> + if (ret < 0) {
> + PERROR("setsockopt TCP_KEEPCNT");
> + goto end;
> + }
> + }
> +
> + /* TCP keep-alive abort threshold */
> + if (support.abort_threshold_supported && config.abort_threshold > 0) {
> + ret = setsockopt(socket_fd, COMPAT_TCP_LEVEL, COMPAT_TCP_ABORT_THRESHOLD, &config.abort_threshold,
> + sizeof(config.max_probe_count));
> + if (ret < 0) {
> + PERROR("setsockopt TCP_KEEPALIVE_ABORT_THRESHOLD");
> + goto end;
> + }
> + }
> +end:
> + return ret;
> +}
> diff --git a/src/bin/lttng-relayd/tcp_keep_alive.h b/src/bin/lttng-relayd/tcp_keep_alive.h
> new file mode 100644
> index 0000000..fb81ecd
> --- /dev/null
> +++ b/src/bin/lttng-relayd/tcp_keep_alive.h
> @@ -0,0 +1,24 @@
> +#ifndef RELAYD_TCP_KEEP_ALIVE_H
> +#define RELAYD_TCP_KEEP_ALIVE_H
> +
> +/*
> + * Copyright (C) 2017 - Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2 only,
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +int tcp_keep_alive_init(void);
> +int socket_apply_keep_alive_config(int socket_fd);
> +
> +#endif /* RELAYD_TCP_KEEP_ALIVE_H */
> diff --git a/src/common/defaults.h b/src/common/defaults.h
> index 31a1fe0..083e1ab 100644
> --- a/src/common/defaults.h
> +++ b/src/common/defaults.h
> @@ -331,6 +331,13 @@
> /* Default maximal size of message notification channel message payloads. */
> #define DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT 100
>
> +
> +#define DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ENV "LTTNG_RELAYD_TCP_KEEP_ALIVE"
> +#define DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME_ENV "LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME"
> +#define DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT_ENV "LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT"
> +#define DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL_ENV "LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL"
> +#define DEFAULT_LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD_ENV "LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD"
> +
> /*
> * Returns the default subbuf size.
> *
> --
> 2.7.4
>
--
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com
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