stream: Introduce API to set several transport parameters

This will allow extending capabilitites to set different parameters at
the lower layers as we need them.

This commit changes the behavior of osmo_stream_{cli,srv_link}: It now
doesn't enable by default SCTP AUTH/ASCONF features using setsockopt. It
is left up to the user of the API (libosmo-sccp in this case) to set it.
Since this unilateral use of setsockopt() has only been added recently
and we didn't release yet, it's fine changing it. libosmo-sccp will be
changed to unconditionally set its using setsockopt. It is left up to
the user of the API (libosmo-sccp in this case) to set it.

Related: SYS#6501
Related: SYS#6558
Change-Id: I2607c1c926a625986cd851adc65dd8b4de83d6ab

4 files changed, 85 insertions, 34 deletions

diff --git a/TODO-RELEASE b/TODO-RELEASE
index 830e77b..084ca67 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -8,4 +8,5 @@
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what		description / commit summary line
 libosmocore		>1.8.0		osmo_iofd, osmo_sock_init2_multiaddr2()
-stream			NEW API		osmo_stream_srv_link_set_name(), osmo_stream_srv_set_name(), osmo_stream_cli_set_name()
\ No newline at end of file
+stream			NEW API		osmo_stream_srv_link_set_name(), osmo_stream_srv_set_name(), osmo_stream_cli_set_name()
+stream			NEW API		osmo_stream_srv_link_set_param(), osmo_stream_cli_set_param()
diff --git a/include/osmocom/netif/stream.h b/include/osmocom/netif/stream.h
index 6240205..f78df8a 100644
--- a/include/osmocom/netif/stream.h
+++ b/include/osmocom/netif/stream.h
@@ -2,6 +2,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <unistd.h>
 
 #include <osmocom/core/msgb.h>
 
@@ -41,6 +42,14 @@ bool osmo_stream_srv_link_is_opened(const struct osmo_stream_srv_link *link);
 int osmo_stream_srv_link_open(struct osmo_stream_srv_link *link);
 void osmo_stream_srv_link_close(struct osmo_stream_srv_link *link);
 
+enum osmo_stream_srv_link_param {
+	OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_AUTH_SUPPORTED, /* uint8_t: 0 disable, 1 enable, 2 force disable, 3 force enable */
+	OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED, /* uint8_t: 0 disable, 1 enable, 2 force disable, 3 force enable */
+};
+
+int osmo_stream_srv_link_set_param(struct osmo_stream_srv_link *link, enum osmo_stream_srv_link_param par,
+				   void *val, size_t val_len);
+
 /*! \brief Osmocom Stream Server: Single connection accept()ed via \ref
  * osmo_stream_srv_link */
 struct osmo_stream_srv;
@@ -105,4 +114,12 @@ int osmo_stream_cli_recv(struct osmo_stream_cli *cli, struct msgb *msg);
 
 void osmo_stream_cli_clear_tx_queue(struct osmo_stream_cli *cli);
 
+enum osmo_stream_cli_param {
+	OSMO_STREAM_CLI_PAR_SCTP_SOCKOPT_AUTH_SUPPORTED, /* uint8_t: 0 disable, 1 enable, 2 force disable, 3 force enable */
+	OSMO_STREAM_CLI_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED, /* uint8_t: 0 disable, 1 enable, 2 force disable, 3 force enable */
+};
+
+int osmo_stream_cli_set_param(struct osmo_stream_cli *cli, enum osmo_stream_cli_param par,
+			      void *val, size_t val_len);
+
 /*! @} */
diff --git a/src/stream_cli.c b/src/stream_cli.c
index 8f18bfb..16d033e 100644
--- a/src/stream_cli.c
+++ b/src/stream_cli.c
@@ -122,6 +122,7 @@ struct osmo_stream_cli {
 	void				*data;
 	int				flags;
 	int				reconnect_timeout;
+	struct osmo_sock_init2_multiaddr_pars ma_pars;
 };
 
 void osmo_stream_cli_close(struct osmo_stream_cli *cli);
@@ -420,6 +421,8 @@ struct osmo_stream_cli *osmo_stream_cli_create(void *ctx)
 	cli->reconnect_timeout = 5;	/* default is 5 seconds. */
 	INIT_LLIST_HEAD(&cli->tx_queue);
 
+	cli->ma_pars.sctp.version = 0;
+
 	return cli;
 }
 
@@ -733,9 +736,6 @@ void osmo_stream_cli_destroy(struct osmo_stream_cli *cli)
  */
 int osmo_stream_cli_open2(struct osmo_stream_cli *cli, int reconnect)
 {
-#ifdef HAVE_LIBSCTP
-	struct osmo_sock_init2_multiaddr_pars ma_pars;
-#endif
 	int ret;
 
 	/* we are reconfiguring this socket, close existing first. */
@@ -747,18 +747,11 @@ int osmo_stream_cli_open2(struct osmo_stream_cli *cli, int reconnect)
 	switch (cli->proto) {
 #ifdef HAVE_LIBSCTP
 	case IPPROTO_SCTP:
-		ma_pars = (struct osmo_sock_init2_multiaddr_pars){
-			.sctp = {
-				.version = 0,
-				.sockopt_auth_supported =   {.set = true, .abort_on_failure = false, .value = 1 },
-				.sockopt_asconf_supported = {.set = true, .abort_on_failure = false, .value = 1 },
-			}
-		};
 		ret = osmo_sock_init2_multiaddr2(AF_UNSPEC, SOCK_STREAM, cli->proto,
 						(const char **)cli->local_addr, cli->local_addrcnt, cli->local_port,
 						(const char **)cli->addr, cli->addrcnt, cli->port,
 						OSMO_SOCK_F_CONNECT|OSMO_SOCK_F_BIND|OSMO_SOCK_F_NONBLOCK,
-						&ma_pars);
+						&cli->ma_pars);
 		break;
 #endif
 	default:
@@ -816,9 +809,6 @@ void osmo_stream_cli_set_nodelay(struct osmo_stream_cli *cli, bool nodelay)
  *  \return negative on error, 0 on success */
 int osmo_stream_cli_open(struct osmo_stream_cli *cli)
 {
-#ifdef HAVE_LIBSCTP
-	struct osmo_sock_init2_multiaddr_pars ma_pars;
-#endif
 	int ret, fd = -1;
 
 	/* we are reconfiguring this socket, close existing first. */
@@ -837,18 +827,11 @@ int osmo_stream_cli_open(struct osmo_stream_cli *cli)
 		switch (cli->proto) {
 #ifdef HAVE_LIBSCTP
 		case IPPROTO_SCTP:
-			ma_pars = (struct osmo_sock_init2_multiaddr_pars){
-				.sctp = {
-					.version = 0,
-					.sockopt_auth_supported =   {.set = true, .abort_on_failure = false, .value = 1 },
-					.sockopt_asconf_supported = {.set = true, .abort_on_failure = false, .value = 1 },
-				}
-			};
 			ret = osmo_sock_init2_multiaddr2(cli->sk_domain, cli->sk_type, cli->proto,
 							(const char **)cli->local_addr, cli->local_addrcnt, cli->local_port,
 							(const char **)cli->addr, cli->addrcnt, cli->port,
 							OSMO_SOCK_F_CONNECT|OSMO_SOCK_F_BIND|OSMO_SOCK_F_NONBLOCK,
-							&ma_pars);
+							&cli->ma_pars);
 			break;
 #endif
 		default:
@@ -1018,4 +1001,32 @@ void osmo_stream_cli_clear_tx_queue(struct osmo_stream_cli *cli)
 	}
 }
 
+int osmo_stream_cli_set_param(struct osmo_stream_cli *cli, enum osmo_stream_cli_param par, void *val, size_t val_len)
+{
+	OSMO_ASSERT(cli);
+	uint8_t val8;
+
+	switch (par) {
+	case OSMO_STREAM_CLI_PAR_SCTP_SOCKOPT_AUTH_SUPPORTED:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		val8 = *(uint8_t *)val;
+		cli->ma_pars.sctp.sockopt_auth_supported.set = true;
+		cli->ma_pars.sctp.sockopt_auth_supported.abort_on_failure = val8 > 1;
+		cli->ma_pars.sctp.sockopt_auth_supported.value = (val8 == 1 || val8 == 3) ? 1 : 0;
+		break;
+	case OSMO_STREAM_CLI_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		val8 = *(uint8_t *)val;
+		cli->ma_pars.sctp.sockopt_asconf_supported.set = true;
+		cli->ma_pars.sctp.sockopt_asconf_supported.abort_on_failure = val8 > 1;
+		cli->ma_pars.sctp.sockopt_asconf_supported.value = (val8 == 1 || val8 == 3) ? 1 : 0;
+		break;
+	default:
+		return -ENOENT;
+	};
+	return 0;
+}
+
 /*! @} */
diff --git a/src/stream_srv.c b/src/stream_srv.c
index 9818864..186ec02 100644
--- a/src/stream_srv.c
+++ b/src/stream_srv.c
@@ -95,6 +95,7 @@ struct osmo_stream_srv_link {
 	int (*accept_cb)(struct osmo_stream_srv_link *srv, int fd);
 	void			*data;
 	int			flags;
+	struct osmo_sock_init2_multiaddr_pars ma_pars;
 };
 
 static int _setsockopt_nosigpipe(struct osmo_stream_srv_link *link, int new_fd)
@@ -191,6 +192,8 @@ struct osmo_stream_srv_link *osmo_stream_srv_link_create(void *ctx)
 	link->proto = IPPROTO_TCP;
 	osmo_fd_setup(&link->ofd, -1, OSMO_FD_READ | OSMO_FD_WRITE, osmo_stream_srv_link_ofd_cb, link, 0);
 
+	link->ma_pars.sctp.version = 0;
+
 	return link;
 }
 
@@ -387,9 +390,6 @@ void osmo_stream_srv_link_destroy(struct osmo_stream_srv_link *link)
  *  \return negative on error, 0 on success */
 int osmo_stream_srv_link_open(struct osmo_stream_srv_link *link)
 {
-#ifdef HAVE_LIBSCTP
-	struct osmo_sock_init2_multiaddr_pars ma_pars;
-#endif
 	int ret;
 
 	if (link->ofd.fd >= 0) {
@@ -412,16 +412,9 @@ int osmo_stream_srv_link_open(struct osmo_stream_srv_link *link)
 		switch (link->proto) {
 #ifdef HAVE_LIBSCTP
 		case IPPROTO_SCTP:
-			ma_pars = (struct osmo_sock_init2_multiaddr_pars){
-				.sctp = {
-					.version = 0,
-					.sockopt_auth_supported =   {.set = true, .abort_on_failure = false, .value = 1 },
-					.sockopt_asconf_supported = {.set = true, .abort_on_failure = false, .value = 1 },
-				}
-			};
 			ret = osmo_sock_init2_multiaddr2(link->sk_domain, link->sk_type, link->proto,
 							 (const char **)link->addr, link->addrcnt, link->port,
-							 NULL, 0, 0, OSMO_SOCK_F_BIND, &ma_pars);
+							 NULL, 0, 0, OSMO_SOCK_F_BIND, &link->ma_pars);
 			break;
 #endif
 		default:
@@ -472,6 +465,35 @@ void osmo_stream_srv_link_close(struct osmo_stream_srv_link *link)
 	link->ofd.fd = -1;
 }
 
+int osmo_stream_srv_link_set_param(struct osmo_stream_srv_link *link, enum osmo_stream_srv_link_param par,
+				   void *val, size_t val_len)
+{
+	OSMO_ASSERT(link);
+	uint8_t val8;
+
+	switch (par) {
+	case OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_AUTH_SUPPORTED:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		val8 = *(uint8_t *)val;
+		link->ma_pars.sctp.sockopt_auth_supported.set = true;
+		link->ma_pars.sctp.sockopt_auth_supported.abort_on_failure = val8 > 1;
+		link->ma_pars.sctp.sockopt_auth_supported.value = (val8 == 1 || val8 == 3) ? 1 : 0;
+		break;
+	case OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED:
+		if (!val || val_len != sizeof(uint8_t))
+			return -EINVAL;
+		val8 = *(uint8_t *)val;
+		link->ma_pars.sctp.sockopt_asconf_supported.set = true;
+		link->ma_pars.sctp.sockopt_asconf_supported.abort_on_failure = val8 > 1;
+		link->ma_pars.sctp.sockopt_asconf_supported.value = (val8 == 1 || val8 == 3) ? 1 : 0;
+		break;
+	default:
+		return -ENOENT;
+	};
+	return 0;
+}
+
 #define OSMO_STREAM_SRV_F_FLUSH_DESTROY	(1 << 0)
 
 struct osmo_stream_srv {