[M] Change in libosmo-netif[master]: stream: Support configuring TCP keep-alive pars

17 Jun 2025

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-netif/+/40478?usp=email )
Change subject: stream: Support configuring TCP keep-alive pars
......................................................................
stream: Support configuring TCP keep-alive pars
for servers, the param can either be set on the link (which will be
automatically inherited/applied for all accepted conn sockets), or can
be set specifically on a srv conn socket.
The second is useful when user can supply different parameters for different
clients connected to the listening socket, eg. ASP configuration in
libosmo-sigtran.
Change-Id: Ie748ad581c1c42f4c24f9409ce7d34d419cbca8b
---
M TODO-RELEASE
M include/osmocom/netif/stream.h
M include/osmocom/netif/stream_private.h
M src/stream.c
M src/stream_cli.c
M src/stream_srv.c
6 files changed, 237 insertions(+), 3 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmo-netif refs/changes/78/40478/1

diff --git a/TODO-RELEASE b/TODO-RELEASE
index 0ed7189..e519375 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -7,3 +7,4 @@
 # If any interfaces have been added since the last public release: c:r:a + 1.
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what			description / commit summary line
+stream    add       OSMO_STREAM_{CLI,SRV,SRV_LINK}_TCP_SOCKOPT_KEEP*, osmo_stream_srv_set_param()
diff --git a/include/osmocom/netif/stream.h b/include/osmocom/netif/stream.h
index 075e5e9..7b74e87 100644
--- a/include/osmocom/netif/stream.h
+++ b/include/osmocom/netif/stream.h
@@ -98,6 +98,11 @@
    OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED, /* uint8_t: 0 disable, 1 enable, 2 force disable, 3 force enable */
    OSMO_STREAM_SRV_LINK_PAR_SCTP_INIT_NUM_OSTREAMS, /* uint16_t: amount of streams */
    OSMO_STREAM_SRV_LINK_PAR_SCTP_INIT_MAX_INSTREAMS, /* uint16_t: amount of streams */
+
+	OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPALIVE = 256, /* uint8_t: 0 disable, 1 enable */
+	OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPIDLE, /* int: seconds */
+	OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPINTVL, /* int: seconds */
+	OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPCNT, /* int: Number of probes */
 };
int osmo_stream_srv_link_set_param(struct osmo_stream_srv_link *link, enum osmo_stream_srv_link_param par,
@@ -149,6 +154,15 @@
void osmo_stream_srv_clear_tx_queue(struct osmo_stream_srv *conn);
+enum osmo_stream_srv_param {
+	OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPALIVE = 256, /* uint8_t: 0 disable, 1 enable */
+	OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPIDLE, /* int: seconds */
+	OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPINTVL, /* int: seconds */
+	OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPCNT, /* int: Number of probes */
+};
+int osmo_stream_srv_set_param(struct osmo_stream_srv *conn, enum osmo_stream_srv_param par,
+			       void *val, size_t val_len);
+
 /*! @} */
/*! \defgroup stream_cli Osmocom Stream Client
@@ -255,6 +269,11 @@
    OSMO_STREAM_CLI_PAR_SCTP_INIT_MAX_INSTREAMS, /* uint16_t: amount of streams */
    OSMO_STREAM_CLI_PAR_SCTP_INIT_MAX_ATTEMPTS, /* uint16_t: amount of attempts */
    OSMO_STREAM_CLI_PAR_SCTP_INIT_TIMEOUT, /* uint16_t: milliseconds */
+
+	OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPALIVE = 256, /* uint8_t: 0 disable, 1 enable */
+	OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPIDLE, /* int: seconds */
+	OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPINTVL, /* int: seconds */
+	OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPCNT, /* int: Number of probes */
 };
int osmo_stream_cli_set_param(struct osmo_stream_cli *cli, enum osmo_stream_cli_param par,
diff --git a/include/osmocom/netif/stream_private.h b/include/osmocom/netif/stream_private.h
index dc7506d..7fb0de6 100644
--- a/include/osmocom/netif/stream_private.h
+++ b/include/osmocom/netif/stream_private.h
@@ -29,6 +29,26 @@
    OSMO_STREAM_MODE_OSMO_IO,
 };
+struct stream_tcp_keepalive_pars {
+	bool enable;
+	bool time_present;
+	bool intvl_present;
+	bool probes_present;
+	int time_value; /* seconds */
+	int intvl_value; /* seconds */
+	int probes_value;
+};
+int stream_setsockopt_tcp_keepalive(int fd, int on);
+int stream_setsockopt_tcp_keepidle(int fd, int keepalive_time);
+int stream_setsockopt_tcp_keepintvl(int fd, int keepalive_intvl);
+int stream_setsockopt_tcp_keepcnt(int fd, int keepalive_probes);
+int stream_tcp_keepalive_pars_apply(int fd, const struct stream_tcp_keepalive_pars *tkp);
+
+struct stream_tcp_pars {
+	struct stream_tcp_keepalive_pars ka;
+	/* Others like TCP_USER_TIMEOUT will be added here in the future. */
+};
+
 struct osmo_io_fd;
 struct msghdr;
diff --git a/src/stream.c b/src/stream.c
index f0902a4..a1e077a 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -196,6 +196,78 @@
    return rc;
 }
+int stream_setsockopt_tcp_keepalive(int fd, int on)
+{
+	int ret = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on));
+	if (ret < 0) {
+		ret = errno;
+		LOGP(DLINP, LOGL_ERROR, "Failed to enable TCP keepalive on fd %d: %s\n", fd, strerror(ret));
+		return -ret;
+	}
+	return 0;
+}
+
+int stream_setsockopt_tcp_keepidle(int fd, int keepalive_time)
+{
+	int ret = setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &keepalive_time, sizeof(keepalive_time));
+	if (ret < 0) {
+		ret = errno;
+		LOGP(DLINP, LOGL_ERROR, "Failed to set TCP_KEEPIDLE on fd %d: %s\n", fd, strerror(ret));
+		return -ret;
+	}
+	return 0;
+}
+
+int stream_setsockopt_tcp_keepintvl(int fd, int keepalive_intvl)
+{
+	int ret = setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &keepalive_intvl, sizeof(keepalive_intvl));
+	if (ret < 0) {
+		ret = errno;
+		LOGP(DLINP, LOGL_ERROR, "Failed to set TCP_KEEPINTVL on fd %d: %s\n", fd, strerror(ret));
+		return -ret;
+	}
+	return 0;
+}
+
+int stream_setsockopt_tcp_keepcnt(int fd, int keepalive_probes)
+{
+	int ret = setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &keepalive_probes, sizeof(keepalive_probes));
+	if (ret < 0) {
+		ret = errno;
+		LOGP(DLINP, LOGL_ERROR, "Failed to set TCP_KEEPCNT on fd %d: %s\n", fd, strerror(ret));
+		return -ret;
+	}
+	return 0;
+}
+
+int stream_tcp_keepalive_pars_apply(int fd, const struct stream_tcp_keepalive_pars *tkp)
+{
+	int ret;
+
+	if (!tkp->enable)
+		return 0;
+
+	if ((ret = stream_setsockopt_tcp_keepalive(fd, tkp->enable)) < 0)
+		return ret;
+
+	if (tkp->time_present) {
+		if ((ret = stream_setsockopt_tcp_keepidle(fd, tkp->time_value)) < 0)
+			return ret;
+	}
+
+	if (tkp->intvl_present) {
+		if ((ret = stream_setsockopt_tcp_keepintvl(fd, tkp->intvl_value)) < 0)
+			return ret;
+	}
+
+	if (tkp->probes_present) {
+		if ((ret = stream_setsockopt_tcp_keepcnt(fd, tkp->probes_value)) < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
 #ifdef HAVE_LIBSCTP
 static int stream_sctp_recvmsg_trailer(const char *log_pfx, struct msgb *msg, int ret, const struct sctp_sndrcvinfo *sinfo, int flags)
 {
diff --git a/src/stream_cli.c b/src/stream_cli.c
index 028ab07..4b20a61 100644
--- a/src/stream_cli.c
+++ b/src/stream_cli.c
@@ -122,6 +122,7 @@
    int				flags;
    int				reconnect_timeout;
    struct osmo_sock_init2_multiaddr_pars ma_pars;
+	struct stream_tcp_pars		tcp_pars;
    uint8_t				in_cb_mask; /* IN_CB_MASK_* */
    bool				delay_free;
 };
@@ -1286,6 +1287,12 @@
    		goto error_close_socket;
    }
+	if (cli->proto == IPPROTO_TCP) {
+		ret = stream_tcp_keepalive_pars_apply(fd, &cli->tcp_pars.ka);
+		if (ret < 0)
+			goto error_close_socket;
+	}
+
    switch (cli->mode) {
    case OSMO_STREAM_MODE_OSMO_FD:
    	osmo_fd_setup(&cli->ofd, fd, OSMO_FD_READ | OSMO_FD_WRITE, osmo_stream_cli_fd_cb, cli, 0);
@@ -1532,6 +1539,38 @@
    	cli->ma_pars.sctp.sockopt_initmsg.max_init_timeo_present = true;
    	cli->ma_pars.sctp.sockopt_initmsg.max_init_timeo_value = *(uint16_t *)val;
    	break;
+	/* TCP keelapive params: */
+	case OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPALIVE:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		cli->tcp_pars.ka.enable = !!*(uint8_t *)val;
+		if (stream_cli_is_opened(cli))
+			return stream_setsockopt_tcp_keepalive(osmo_stream_cli_get_fd(cli), cli->tcp_pars.ka.enable);
+		break;
+	case OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPIDLE:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		cli->tcp_pars.ka.time_present = true;
+		cli->tcp_pars.ka.time_value = *(int *)val;
+		if (stream_cli_is_opened(cli))
+			return stream_setsockopt_tcp_keepidle(osmo_stream_cli_get_fd(cli), cli->tcp_pars.ka.time_value);
+		break;
+	case OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPINTVL:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		cli->tcp_pars.ka.intvl_present = true;
+		cli->tcp_pars.ka.intvl_value = *(int *)val;
+		if (stream_cli_is_opened(cli))
+			return stream_setsockopt_tcp_keepintvl(osmo_stream_cli_get_fd(cli), cli->tcp_pars.ka.intvl_value);
+		break;
+	case OSMO_STREAM_CLI_PAR_TCP_SOCKOPT_KEEPCNT:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		cli->tcp_pars.ka.probes_present = true;
+		cli->tcp_pars.ka.probes_value = *(int *)val;
+		if (stream_cli_is_opened(cli))
+			return stream_setsockopt_tcp_keepcnt(osmo_stream_cli_get_fd(cli), cli->tcp_pars.ka.probes_value);
+		break;
    default:
    	return -ENOENT;
    };
diff --git a/src/stream_srv.c b/src/stream_srv.c
index be950ce..b7bc378 100644
--- a/src/stream_srv.c
+++ b/src/stream_srv.c
@@ -99,6 +99,7 @@
    unsigned int		tx_queue_max_length; /* Max amount of msgbs which can be enqueued */
    struct msgb_alloc_info	msgb_alloc;
    struct osmo_sock_init2_multiaddr_pars ma_pars;
+	struct stream_tcp_pars tcp_pars;
 };
static int _setsockopt_nosigpipe(struct osmo_stream_srv_link *link, int new_fd)
@@ -142,11 +143,22 @@
    	LOGSLNK(link, LOGL_INFO, "accept()ed new link from %s\n",
    		osmo_sockaddr_to_str(&osa));
-		if (link->proto == IPPROTO_SCTP) {
+		switch (link->proto) {
+		case IPPROTO_TCP:
+			ret = stream_tcp_keepalive_pars_apply(sock_fd, &link->tcp_pars.ka);
+			if (ret < 0) {
+				LOGSLNK(link, LOGL_ERROR, "failed applying TCP keep-alive pars on fd %d\n", sock_fd);
+				goto error_close_socket;
+			}
+			break;
+		case IPPROTO_SCTP:
    		_setsockopt_nosigpipe(link, sock_fd);
    		ret = stream_sctp_sock_activate_events(sock_fd);
    		if (ret < 0)
    			goto error_close_socket;
+			break;
+		default:
+			break;
    	}
    	break;
    default:
@@ -628,7 +640,7 @@
 }
/*! Set given parameter of stream_srv_link to given value.
- *  \param[in] cli stream client on which to set parameter.
+ *  \param[in] link stream server link on which to set parameter.
  *  \param[in] par identifier of the parameter to be set.
  *  \param[in] val value of the parameter to be set.
  *  \param[in] val_len length of the parameter value.
@@ -670,6 +682,34 @@
    	link->ma_pars.sctp.sockopt_initmsg.max_instreams_present = true;
    	link->ma_pars.sctp.sockopt_initmsg.max_instreams_value = *(uint16_t *)val;
    	break;
+	/* TCP keelapive params: */
+	case OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPALIVE:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		link->tcp_pars.ka.enable = !!*(uint8_t *)val;
+		/* Will be applied on accepted sockets */
+		break;
+	case OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPIDLE:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		link->tcp_pars.ka.time_present = true;
+		link->tcp_pars.ka.time_value = *(int *)val;
+		/* Will be applied on accepted sockets */
+		break;
+	case OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPINTVL:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		link->tcp_pars.ka.intvl_present = true;
+		link->tcp_pars.ka.intvl_value = *(int *)val;
+		/* Will be applied on accepted sockets */
+		break;
+	case OSMO_STREAM_SRV_LINK_PAR_TCP_SOCKOPT_KEEPCNT:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		link->tcp_pars.ka.probes_present = true;
+		link->tcp_pars.ka.probes_value = *(int *)val;
+		/* Will be applied on accepted sockets */
+		break;
    default:
    	return -ENOENT;
    };
@@ -959,7 +999,10 @@
  *  \param[in] link Stream Server Link to which we belong
  *  \param[in] fd system file descriptor of the new connection
  *  \param[in] data User data to save in the new Stream Server struct
- *  \returns Stream Server in case of success; NULL on error */
+ *  \returns Stream Server in case of success; NULL on error
+ *
+ *  Note: In case of error, the caller is responsible for closing the fd.
+ * */
 struct osmo_stream_srv *
 osmo_stream_srv_create2(void *ctx, struct osmo_stream_srv_link *link, int fd, void *data)
 {
@@ -1394,4 +1437,44 @@
    	osmo_stream_srv_destroy(conn);
 }
+/*! Set given parameter of stream_srv to given value.
+ *  \param[in] conn stream server conn on which to set parameter.
+ *  \param[in] par identifier of the parameter to be set.
+ *  \param[in] val value of the parameter to be set.
+ *  \param[in] val_len length of the parameter value.
+ *  \returns 0 in success; negative -errno on error. */
+int osmo_stream_srv_set_param(struct osmo_stream_srv *conn, enum osmo_stream_srv_param par,
+			      void *val, size_t val_len)
+{
+	uint8_t on;
+	int i;
+	OSMO_ASSERT(conn);
+
+	switch (par) {
+	/* TCP keelapive params: */
+	case OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPALIVE:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		on = !!*(uint8_t *)val;
+		return stream_setsockopt_tcp_keepalive(osmo_stream_srv_get_fd(conn), on);
+	case OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPIDLE:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		i = *(int *)val;
+		return stream_setsockopt_tcp_keepidle(osmo_stream_srv_get_fd(conn), i);
+	case OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPINTVL:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		i = *(int *)val;
+		return stream_setsockopt_tcp_keepintvl(osmo_stream_srv_get_fd(conn), i);
+	case OSMO_STREAM_SRV_PAR_TCP_SOCKOPT_KEEPCNT:
+		if (!val || val_len != sizeof(int))
+			return -EINVAL;
+		i = *(int *)val;
+		return stream_setsockopt_tcp_keepcnt(osmo_stream_srv_get_fd(conn), i);
+	default:
+		return -ENOENT;
+	};
+}
+
 /*! @} */
-- 
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Gerrit-MessageType: newchange
Gerrit-Project: libosmo-netif
Gerrit-Branch: master
Gerrit-Change-Id: Ie748ad581c1c42f4c24f9409ce7d34d419cbca8b
Gerrit-Change-Number: 40478
Gerrit-PatchSet: 1
Gerrit-Owner: pespin pespin@sysmocom.de



    

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[M] Change in libosmo-netif[master]: stream: Support configuring TCP keep-alive pars