File 2023-Implement-TCP_KEEP-and-TCP_USER_TIMEOUT-for-gen_tcp.patch of Package erlang
From f5584207055758f4b320c222cd97bce7b624bd9d Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Mon, 17 Nov 2025 17:17:02 +0100
Subject: [PATCH 3/4] Implement TCP_KEEP* and TCP_USER_TIMEOUT for `gen_tcp`
Options TCP_KEEPCNT, TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_USER_TIMEOUT
with Erlang names `keepcnt`, `keepidle`, `keepintvl` and `user_timeout`
for `gen_tcp` and `inet` `setopts` and `getopts`.
---
erts/emulator/drivers/common/inet_drv.c | 72 +++++++++++++++++++++++++
erts/preloaded/src/prim_inet.erl | 16 +++++-
lib/kernel/src/gen_tcp.erl | 8 +++
lib/kernel/src/gen_tcp_socket.erl | 6 ++-
lib/kernel/src/inet.erl | 15 +++++-
lib/kernel/src/inet_int.hrl | 7 ++-
6 files changed, 118 insertions(+), 6 deletions(-)
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index afa268c089..6455c7a9aa 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -923,6 +923,10 @@ static size_t my_strnlen(const char *s, size_t maxlen)
#define TCP_OPT_NOPUSH 48 /* super-Nagle, aka TCP_CORK */
#define INET_LOPT_TCP_READ_AHEAD 49 /* Read ahead of packet data */
#define INET_LOPT_NON_BLOCK_SEND 50 /* Non-blocking send, only SCTP */
+#define TCP_OPT_KEEPCNT 51 /* TCP_KEEPCNTK */
+#define TCP_OPT_KEEPIDLE 52 /* TCP_KEEPIDLE */
+#define TCP_OPT_KEEPINTVL 53 /* TCP_KEEPINTVL */
+#define TCP_OPT_USER_TIMEOUT 54 /* TCP_USER_TIMEOUT */
#define INET_LOPT_DEBUG 99 /* Enable/disable DEBUG for a socket */
/* SCTP options: a separate range, from 100: */
@@ -7493,6 +7497,50 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
continue;
#endif
+#if defined(TCP_KEEPCNT)
+ case TCP_OPT_KEEPCNT:
+ DDBG(desc,
+ ("INET-DRV-DBG[%d][" SOCKET_FSTR ",%T] "
+ "inet_set_opts(keepcnt) -> %d\r\n",
+ __LINE__, desc->s, driver_caller(desc->port), ival) );
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPCNT;
+ break;
+#endif
+
+#if defined(TCP_KEEPIDLE)
+ case TCP_OPT_KEEPIDLE:
+ DDBG(desc,
+ ("INET-DRV-DBG[%d][" SOCKET_FSTR ",%T] "
+ "inet_set_opts(keepidle) -> %d\r\n",
+ __LINE__, desc->s, driver_caller(desc->port), ival) );
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPIDLE;
+ break;
+#endif
+
+#if defined(TCP_KEEPINTVL)
+ case TCP_OPT_KEEPINTVL:
+ DDBG(desc,
+ ("INET-DRV-DBG[%d][" SOCKET_FSTR ",%T] "
+ "inet_set_opts(keepintvl) -> %d\r\n",
+ __LINE__, desc->s, driver_caller(desc->port), ival) );
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPINTVL;
+ break;
+#endif
+
+#if defined(TCP_USER_TIMEOUT)
+ case TCP_OPT_USER_TIMEOUT:
+ DDBG(desc,
+ ("INET-DRV-DBG[%d][" SOCKET_FSTR ",%T] "
+ "inet_set_opts(user_timeout) -> %d\r\n",
+ __LINE__, desc->s, driver_caller(desc->port), ival) );
+ proto = IPPROTO_TCP;
+ type = TCP_USER_TIMEOUT;
+ break;
+#endif
+
#if defined(HAVE_MULTICAST_SUPPORT) && defined(IPPROTO_IP)
case UDP_OPT_MULTICAST_TTL:
@@ -9380,6 +9428,30 @@ static ErlDrvSSizeT inet_fill_opts(inet_descriptor* desc,
put_int32(0, ptr);
continue;
#endif
+#if defined(TCP_KEEPCNT)
+ case TCP_OPT_KEEPCNT:
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPCNT;
+ break;
+#endif
+#if defined(TCP_KEEPIDLE)
+ case TCP_OPT_KEEPIDLE:
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPIDLE;
+ break;
+#endif
+#if defined(TCP_KEEPINTVL)
+ case TCP_OPT_KEEPINTVL:
+ proto = IPPROTO_TCP;
+ type = TCP_KEEPINTVL;
+ break;
+#endif
+#if defined(TCP_USER_TIMEOUT)
+ case TCP_OPT_USER_TIMEOUT:
+ proto = IPPROTO_TCP;
+ type = TCP_USER_TIMEOUT;
+ break;
+#endif
#if defined(HAVE_MULTICAST_SUPPORT) && defined(IPPROTO_IP)
case UDP_OPT_MULTICAST_TTL:
diff --git a/erts/preloaded/src/prim_inet.erl b/erts/preloaded/src/prim_inet.erl
index 4072a83697..78c415e7c5 100644
--- a/erts/preloaded/src/prim_inet.erl
+++ b/erts/preloaded/src/prim_inet.erl
@@ -1585,7 +1585,11 @@ enc_opt(line_delimiter) -> ?INET_LOPT_LINE_DELIM;
enc_opt(raw) -> ?INET_OPT_RAW;
enc_opt(bind_to_device) -> ?INET_OPT_BIND_TO_DEVICE;
enc_opt(read_ahead) -> ?INET_LOPT_TCP_READ_AHEAD;
-enc_opt(non_block_send) -> ?INET_OPT_NON_BLOCK_SEND;
+enc_opt(non_block_send) -> ?INET_LOPT_NON_BLOCK_SEND;
+enc_opt(keepcnt) -> ?TCP_OPT_KEEPCNT;
+enc_opt(keepidle) -> ?TCP_OPT_KEEPIDLE;
+enc_opt(keepintvl) -> ?TCP_OPT_KEEPINTVL;
+enc_opt(user_timeout) -> ?TCP_OPT_USER_TIMEOUT;
enc_opt(debug) -> ?INET_OPT_DEBUG;
% Names of SCTP opts:
enc_opt(sctp_rtoinfo) -> ?SCTP_OPT_RTOINFO;
@@ -1658,7 +1662,11 @@ dec_opt(?INET_LOPT_LINE_DELIM) -> line_delimiter;
dec_opt(?INET_OPT_RAW) -> raw;
dec_opt(?INET_OPT_BIND_TO_DEVICE) -> bind_to_device;
dec_opt(?INET_LOPT_TCP_READ_AHEAD) -> read_ahead;
-dec_opt(?INET_OPT_NON_BLOCK_SEND) -> non_block_send;
+dec_opt(?INET_LOPT_NON_BLOCK_SEND) -> non_block_send;
+dec_opt(?TCP_OPT_KEEPCNT) -> keepcnt;
+dec_opt(?TCP_OPT_KEEPIDLE) -> keepidle;
+dec_opt(?TCP_OPT_KEEPINTVL) -> keepintvl;
+dec_opt(?TCP_OPT_USER_TIMEOUT) -> user_timeout;
dec_opt(?INET_OPT_DEBUG) -> debug;
dec_opt(I) when is_integer(I) -> undefined.
@@ -1773,6 +1781,10 @@ type_opt_1(show_econnreset) -> bool;
type_opt_1(bind_to_device) -> binary;
type_opt_1(read_ahead) -> bool;
type_opt_1(non_block_send) -> bool;
+type_opt_1(keepcnt) -> int;
+type_opt_1(keepidle) -> int;
+type_opt_1(keepintvl) -> int;
+type_opt_1(user_timeout) -> uint;
type_opt_1(debug) -> bool;
%%
%% SCTP options (to be set). If the type is a record type, the corresponding
diff --git a/lib/kernel/src/gen_tcp.erl b/lib/kernel/src/gen_tcp.erl
index 9b00ae369b..44e23ffc23 100644
--- a/lib/kernel/src/gen_tcp.erl
+++ b/lib/kernel/src/gen_tcp.erl
@@ -274,6 +274,9 @@ way, option `send_timeout` comes in handy.
{high_msgq_watermark, pos_integer()} |
{high_watermark, non_neg_integer()} |
{keepalive, boolean()} |
+ {keepcnt, integer()} |
+ {keepidle, integer()} |
+ {keepintvl, integer()} |
{linger, {boolean(), non_neg_integer()}} |
{low_msgq_watermark, pos_integer()} |
{low_watermark, non_neg_integer()} |
@@ -302,6 +305,7 @@ way, option `send_timeout` comes in handy.
{recvtos, boolean()} |
{recvtclass, boolean()} |
{recvttl, boolean()} |
+ {user_timeout, non_neg_integer()} |
{ipv6_v6only, boolean()}.
-doc """
@@ -337,6 +341,9 @@ this value is returned from `inet:getopts/2` when called with the option name
high_msgq_watermark |
high_watermark |
keepalive |
+ keepcnt |
+ keepidle |
+ keepintvl |
linger |
low_msgq_watermark |
low_watermark |
@@ -365,6 +372,7 @@ this value is returned from `inet:getopts/2` when called with the option name
recvtclass |
recvttl |
pktoptions |
+ user_timeout |
ipv6_v6only.
-type connect_option() ::
{fd, Fd :: non_neg_integer()} |
diff --git a/lib/kernel/src/gen_tcp_socket.erl b/lib/kernel/src/gen_tcp_socket.erl
index 4bd303d9bd..9bd03c9d6b 100644
--- a/lib/kernel/src/gen_tcp_socket.erl
+++ b/lib/kernel/src/gen_tcp_socket.erl
@@ -1284,7 +1284,11 @@ socket_opts() ->
%%
%% Level: tcp
- nodelay => {tcp, nodelay},
+ keepcnt => {tcp, keepcnt},
+ keepidle => {tcp, keepidle},
+ keepintvl => {tcp, keepintvl},
+ nodelay => {tcp, nodelay},
+ user_timeout => {tcp, user_timeout},
%%
%% Level: ip
diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index a0095fdcc8..073e16633c 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -1115,6 +1115,12 @@ The following options are available:
other end does not respond, the connection is considered broken and an error
message is sent to the controlling process. Defaults to `false`.
+- **`{keepcnt, Integer}` (TCP/IP sockets)** - Linux specific `TCP_KEEPCNT`.
+
+- **`{keepidle, Integer}` (TCP/IP sockets)** - Linux specific `TCP_KEEPIDLE`.
+
+- **`{keepintvl, Integer}` (TCP/IP sockets)** - Linux specific `TCP_KEEPINTVL`.
+
- **`{linger, {true|false, Seconds}}`** [](){: #option-linger } -
Determines the time-out, in seconds, for flushing unsent data
in the [`close/1`](`close/1`) socket call.
@@ -1513,6 +1519,9 @@ The following options are available:
different systems. The option is ignored on platforms where it is not
implemented. Use with caution.
+- **`{user_timeout, Integer}` (TCP/IP sockets)** - Linux specific
+ `TCP_USER_TIMEOUT`.
+
In addition to these options, _raw_ option specifications can be used. The raw
options are specified as a tuple of arity four, beginning with tag `raw`,
followed by the protocol level, the option number, and the option value
@@ -3101,7 +3110,8 @@ connect_options() ->
header, active, packet, packet_size, buffer, mode, deliver, line_delimiter,
exit_on_close, high_watermark, low_watermark, high_msgq_watermark,
low_msgq_watermark, send_timeout, send_timeout_close, delay_send, raw,
- show_econnreset, bind_to_device, read_ahead].
+ show_econnreset, bind_to_device, read_ahead,
+ keepcnt, keepidle, keepintvl, user_timeout].
-doc false.
connect_options(Opts, Mod) ->
@@ -3197,7 +3207,8 @@ listen_options() ->
header, active, packet, buffer, mode, deliver, backlog, ipv6_v6only,
exit_on_close, high_watermark, low_watermark, high_msgq_watermark,
low_msgq_watermark, send_timeout, send_timeout_close, delay_send,
- packet_size, raw, show_econnreset, bind_to_device, read_ahead].
+ packet_size, raw, show_econnreset, bind_to_device, read_ahead,
+ keepcnt, keepidle, keepintvl, user_timeout].
-doc false.
listen_options(Opts, Mod) ->
diff --git a/lib/kernel/src/inet_int.hrl b/lib/kernel/src/inet_int.hrl
index bb8457a605..c9bc4cc084 100644
--- a/lib/kernel/src/inet_int.hrl
+++ b/lib/kernel/src/inet_int.hrl
@@ -177,8 +177,13 @@
-define(INET_OPT_RECVTTL, 47).
-define(TCP_OPT_NOPUSH, 48).
-define(INET_LOPT_TCP_READ_AHEAD, 49).
--define(INET_OPT_NON_BLOCK_SEND, 50).
+-define(INET_LOPT_NON_BLOCK_SEND, 50).
+-define(TCP_OPT_KEEPCNT, 51).
+-define(TCP_OPT_KEEPIDLE, 52).
+-define(TCP_OPT_KEEPINTVL, 53).
+-define(TCP_OPT_USER_TIMEOUT, 54).
-define(INET_OPT_DEBUG, 99).
+
% Specific SCTP options: separate range:
-define(SCTP_OPT_RTOINFO, 100).
-define(SCTP_OPT_ASSOCINFO, 101).
--
2.51.0
