Replace NNG_OPT_SUB_SUBSCRIBE/UNSUBSCRIBE with functions.

The main purpose is to eliminate the NNI_TYPE_OPAQUE options,
by putting these into their own first class, protocol-specific, functions.

12 files changed, 162 insertions, 89 deletions

diff --git a/docs/ref/migrate/nanomsg.md b/docs/ref/migrate/nanomsg.md
index 695f771b..67e6505a 100644
--- a/docs/ref/migrate/nanomsg.md
+++ b/docs/ref/migrate/nanomsg.md
@@ -84,6 +84,8 @@ The following options are changed.
 | `NN_IPV4ONLY`          | None                          | Use URL such as `tcp4://` to obtain this functionality. |
 | `NN_SOCKET_NAME`       | `NNG_OPT_SOCKNAME`            |
 | `NN_MAXTTL`            | `NNG_OPT_MAXTTL`              |
+| `NN_SUB_SUBSCRIBE`     | `nng_sub0_socket_subscribe`   | No longer an option, use a function call.               |
+| `NN_SUB_UNSUBSCRIBE`   | `nng_sub0_socket_unsubscribe` | No longer an option, use a function call.               |
 
 ## Error Codes
 
diff --git a/docs/ref/migrate/nng1.md b/docs/ref/migrate/nng1.md
index 3004b880..65af2382 100644
--- a/docs/ref/migrate/nng1.md
+++ b/docs/ref/migrate/nng1.md
@@ -80,6 +80,13 @@ matching the actual wire protocol values, instead of `int`.
 
 The `NNG_OPT_RAW` option has aso been replaced by a function, `nng_socket_raw`.
 
+## Subscriptions
+
+The `NNG_OPT_SUB_SUBSCRIBE` and `NNG_OPT_SUB_UNSUBCRIBE` options have been replaced by
+the following functions: `nng_sub0_socket_subscribe`, `nng_sub0_socket_unsubscribe`,
+`nng_sub0_ctx_subscribe` and `nng_sub0_ctx_unsubscribe`. These functions, like the options
+they replace, are only applicable to SUB sockets.
+
 ## Statistics Use Constified Pointers
 
 A number of the statistics functions take, or return, `const nng_stat *` instead
diff --git a/include/nng/protocol/pubsub0/sub.h b/include/nng/protocol/pubsub0/sub.h
index 81f50a80..a8a37823 100644
--- a/include/nng/protocol/pubsub0/sub.h
+++ b/include/nng/protocol/pubsub0/sub.h
@@ -11,6 +11,8 @@
 #ifndef NNG_PROTOCOL_PUBSUB0_SUB_H
 #define NNG_PROTOCOL_PUBSUB0_SUB_H
 
+#include <nng/nng.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -19,6 +21,13 @@ NNG_DECL int nng_sub0_open(nng_socket *);
 
 NNG_DECL int nng_sub0_open_raw(nng_socket *);
 
+NNG_DECL int nng_sub0_socket_subscribe(
+    nng_socket id, const void *buf, size_t sz);
+NNG_DECL int nng_sub0_socket_unsubscribe(
+    nng_socket id, const void *buf, size_t sz);
+NNG_DECL int nng_sub0_ctx_subscribe(nng_ctx id, const void *buf, size_t sz);
+NNG_DECL int nng_sub0_ctx_unsubscribe(nng_ctx id, const void *buf, size_t sz);
+
 #ifndef nng_sub_open
 #define nng_sub_open nng_sub0_open
 #endif
@@ -27,9 +36,6 @@ NNG_DECL int nng_sub0_open_raw(nng_socket *);
 #define nng_sub_open_raw nng_sub0_open_raw
 #endif
 
-#define NNG_OPT_SUB_SUBSCRIBE "sub:subscribe"
-#define NNG_OPT_SUB_UNSUBSCRIBE "sub:unsubscribe"
-
 #define NNG_OPT_SUB_PREFNEW "sub:prefnew"
 
 #ifdef __cplusplus
diff --git a/src/core/socket.c b/src/core/socket.c
index b01938e5..1e0b0404 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -824,6 +824,18 @@ nni_sock_proto_pipe_ops(nni_sock *sock)
 	return (&sock->s_pipe_ops);
 }
 
+struct nni_proto_sock_ops *
+nni_sock_proto_ops(nni_sock *sock)
+{
+	return (&sock->s_sock_ops);
+}
+
+struct nni_proto_ctx_ops *
+nni_ctx_proto_ops(nni_ctx *ctx)
+{
+	return (&ctx->c_ops);
+}
+
 void *
 nni_sock_proto_data(nni_sock *sock)
 {
@@ -1142,6 +1154,12 @@ nni_ctx_find(nni_ctx **cp, uint32_t id, bool closing)
 	return (rv);
 }
 
+void *
+nni_ctx_proto_data(nni_ctx *ctx)
+{
+	return (ctx->c_data);
+}
+
 static void
 nni_ctx_destroy(nni_ctx *ctx)
 {
diff --git a/src/core/socket.h b/src/core/socket.h
index 8fab08d6..3eb943f4 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -26,7 +26,9 @@ extern bool        nni_sock_raw(nni_sock *);
 extern void       *nni_sock_proto_data(nni_sock *);
 extern void        nni_sock_add_stat(nni_sock *, nni_stat_item *);
 
+extern struct nni_proto_sock_ops *nni_sock_proto_ops(nni_sock *);
 extern struct nni_proto_pipe_ops *nni_sock_proto_pipe_ops(nni_sock *);
+extern struct nni_proto_ctx_ops  *nni_ctx_proto_ops(nni_ctx *);
 
 extern int nni_sock_setopt(
     nni_sock *, const char *, const void *, size_t, nni_opt_type);
@@ -77,6 +79,8 @@ extern int nni_ctx_open(nni_ctx **, nni_sock *);
 // NNG_ECLOSED unless the final argument is true.)
 extern int nni_ctx_find(nni_ctx **, uint32_t, bool);
 
+extern void *nni_ctx_proto_data(nni_ctx *);
+
 // nni_ctx_rele is called to release a hold on the context.  These holds
 // are acquired by either nni_ctx_open or nni_ctx_find.  If the context
 // is being closed (nni_ctx_close was called), and this is the last reference,
diff --git a/src/sp/protocol/pubsub0/pub_test.c b/src/sp/protocol/pubsub0/pub_test.c
index 733d6fb5..f3cf6e2d 100644
--- a/src/sp/protocol/pubsub0/pub_test.c
+++ b/src/sp/protocol/pubsub0/pub_test.c
@@ -141,7 +141,7 @@ test_pub_send_queued(void)
 	// test to be really meaningful.
 	NUTS_PASS(nng_pub0_open(&pub));
 	NUTS_PASS(nng_sub0_open(&sub));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "", 0));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "", 0));
 	NUTS_PASS(nng_socket_set_int(pub, NNG_OPT_SENDBUF, 10));
 	NUTS_PASS(nng_socket_set_int(sub, NNG_OPT_RECVBUF, 10));
 	NUTS_PASS(nng_socket_set_ms(pub, NNG_OPT_SENDTIMEO, 1000));
diff --git a/src/sp/protocol/pubsub0/sub.c b/src/sp/protocol/pubsub0/sub.c
index 5d6a2a05..a4741114 100644
--- a/src/sp/protocol/pubsub0/sub.c
+++ b/src/sp/protocol/pubsub0/sub.c
@@ -13,6 +13,7 @@
 #include <string.h>
 
 #include "core/nng_impl.h"
+#include "core/socket.h"
 #include "nng/protocol/pubsub0/sub.h"
 
 // Subscriber protocol.  The SUB protocol receives messages sent to
@@ -454,13 +455,11 @@ sub0_ctx_set_recv_buf_len(void *arg, const void *buf, size_t sz, nni_type t)
 // to replace this with a patricia trie, like old nanomsg had.
 
 static int
-sub0_ctx_subscribe(void *arg, const void *buf, size_t sz, nni_type t)
+sub0_ctx_subscribe(sub0_ctx *ctx, const void *buf, size_t sz)
 {
-	sub0_ctx   *ctx  = arg;
 	sub0_sock  *sock = ctx->sock;
 	sub0_topic *topic;
 	sub0_topic *new_topic;
-	NNI_ARG_UNUSED(t);
 
 	nni_mtx_lock(&sock->lk);
 	NNI_LIST_FOREACH (&ctx->topics, topic) {
@@ -492,13 +491,11 @@ sub0_ctx_subscribe(void *arg, const void *buf, size_t sz, nni_type t)
 }
 
 static int
-sub0_ctx_unsubscribe(void *arg, const void *buf, size_t sz, nni_type t)
+sub0_ctx_unsubscribe(sub0_ctx *ctx, const void *buf, size_t sz)
 {
-	sub0_ctx   *ctx  = arg;
 	sub0_sock  *sock = ctx->sock;
 	sub0_topic *topic;
 	size_t      len;
-	NNI_ARG_UNUSED(t);
 
 	nni_mtx_lock(&sock->lk);
 	NNI_LIST_FOREACH (&ctx->topics, topic) {
@@ -580,14 +577,6 @@ static nni_option sub0_ctx_options[] = {
 	    .o_set  = sub0_ctx_set_recv_buf_len,
 	},
 	{
-	    .o_name = NNG_OPT_SUB_SUBSCRIBE,
-	    .o_set  = sub0_ctx_subscribe,
-	},
-	{
-	    .o_name = NNG_OPT_SUB_UNSUBSCRIBE,
-	    .o_set  = sub0_ctx_unsubscribe,
-	},
-	{
 	    .o_name = NNG_OPT_SUB_PREFNEW,
 	    .o_get  = sub0_ctx_get_prefer_new,
 	    .o_set  = sub0_ctx_set_prefer_new,
@@ -637,20 +626,6 @@ sub0_sock_set_recv_buf_len(void *arg, const void *buf, size_t sz, nni_type t)
 }
 
 static int
-sub0_sock_subscribe(void *arg, const void *buf, size_t sz, nni_type t)
-{
-	sub0_sock *sock = arg;
-	return (sub0_ctx_subscribe(&sock->master, buf, sz, t));
-}
-
-static int
-sub0_sock_unsubscribe(void *arg, const void *buf, size_t sz, nni_type t)
-{
-	sub0_sock *sock = arg;
-	return (sub0_ctx_unsubscribe(&sock->master, buf, sz, t));
-}
-
-static int
 sub0_sock_get_prefer_new(void *arg, void *buf, size_t *szp, nni_type t)
 {
 	sub0_sock *sock = arg;
@@ -686,14 +661,6 @@ static nni_proto_ctx_ops sub0_ctx_ops = {
 
 static nni_option sub0_sock_options[] = {
 	{
-	    .o_name = NNG_OPT_SUB_SUBSCRIBE,
-	    .o_set  = sub0_sock_subscribe,
-	},
-	{
-	    .o_name = NNG_OPT_SUB_UNSUBSCRIBE,
-	    .o_set  = sub0_sock_unsubscribe,
-	},
-	{
 	    .o_name = NNG_OPT_RECVBUF,
 	    .o_get  = sub0_sock_get_recv_buf_len,
 	    .o_set  = sub0_sock_set_recv_buf_len,
@@ -736,3 +703,91 @@ nng_sub0_open(nng_socket *sock)
 {
 	return (nni_proto_open(sock, &sub0_proto));
 }
+
+int
+nng_sub0_socket_subscribe(nng_socket id, const void *buf, size_t sz)
+{
+	int        rv;
+	nni_sock  *s;
+	sub0_sock *sock;
+
+	if (((rv = nni_init()) != 0) ||
+	    ((rv = nni_sock_find(&s, id.id)) != 0)) {
+		return (rv);
+	}
+	// validate the socket type
+	if (nni_sock_proto_ops(s)->sock_init != sub0_sock_init) {
+		nni_sock_rele(s);
+		return (NNG_ENOTSUP);
+	}
+	sock = nni_sock_proto_data(s);
+	rv   = sub0_ctx_subscribe(&sock->master, buf, sz);
+	nni_sock_rele(s);
+	return (rv);
+}
+
+int
+nng_sub0_socket_unsubscribe(nng_socket id, const void *buf, size_t sz)
+{
+	int        rv;
+	nni_sock  *s;
+	sub0_sock *sock;
+
+	if (((rv = nni_init()) != 0) ||
+	    ((rv = nni_sock_find(&s, id.id)) != 0)) {
+		return (rv);
+	}
+	// validate the socket type
+	if (nni_sock_proto_ops(s)->sock_init != sub0_sock_init) {
+		nni_sock_rele(s);
+		return (NNG_ENOTSUP);
+	}
+	sock = nni_sock_proto_data(s);
+	rv   = sub0_ctx_unsubscribe(&sock->master, buf, sz);
+	nni_sock_rele(s);
+	return (rv);
+}
+
+int
+nng_sub0_ctx_subscribe(nng_ctx id, const void *buf, size_t sz)
+{
+	int       rv;
+	nni_ctx  *c;
+	sub0_ctx *ctx;
+
+	if (((rv = nni_init()) != 0) ||
+	    ((rv = nni_ctx_find(&c, id.id, false)) != 0)) {
+		return (rv);
+	}
+	// validate the socket type
+	if (nni_ctx_proto_ops(c)->ctx_init != sub0_ctx_init) {
+		nni_ctx_rele(c);
+		return (NNG_ENOTSUP);
+	}
+	ctx = nni_ctx_proto_data(c);
+	rv  = sub0_ctx_subscribe(ctx, buf, sz);
+	nni_ctx_rele(c);
+	return (rv);
+}
+
+int
+nng_sub0_ctx_unsubscribe(nng_ctx id, const void *buf, size_t sz)
+{
+	int       rv;
+	nni_ctx  *c;
+	sub0_ctx *ctx;
+
+	if (((rv = nni_init()) != 0) ||
+	    ((rv = nni_ctx_find(&c, id.id, false)) != 0)) {
+		return (rv);
+	}
+	// validate the socket type
+	if (nni_ctx_proto_ops(c)->ctx_init != sub0_ctx_init) {
+		nni_ctx_rele(c);
+		return (NNG_ENOTSUP);
+	}
+	ctx = nni_ctx_proto_data(c);
+	rv  = sub0_ctx_unsubscribe(ctx, buf, sz);
+	nni_ctx_rele(c);
+	return (rv);
+}
diff --git a/src/sp/protocol/pubsub0/sub_test.c b/src/sp/protocol/pubsub0/sub_test.c
index 9802a35e..9929de64 100644
--- a/src/sp/protocol/pubsub0/sub_test.c
+++ b/src/sp/protocol/pubsub0/sub_test.c
@@ -82,7 +82,7 @@ test_sub_poll_readable(void)
 
 	NUTS_PASS(nng_sub0_open(&sub));
 	NUTS_PASS(nng_pub0_open(&pub));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "a", 1));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "a", 1));
 	NUTS_PASS(nng_socket_set_ms(sub, NNG_OPT_RECVTIMEO, 1000));
 	NUTS_PASS(nng_socket_set_ms(pub, NNG_OPT_SENDTIMEO, 1000));
 	NUTS_PASS(nng_socket_get_recv_poll_fd(sub, &fd));
@@ -126,7 +126,7 @@ test_sub_recv_late(void)
 	NUTS_PASS(nng_sub0_open(&sub));
 	NUTS_PASS(nng_pub0_open(&pub));
 	NUTS_PASS(nng_aio_alloc(&aio, NULL, NULL));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "", 0));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "", 0));
 	NUTS_PASS(nng_socket_set_ms(sub, NNG_OPT_RECVTIMEO, 1000));
 	NUTS_PASS(nng_socket_set_ms(pub, NNG_OPT_SENDTIMEO, 1000));
 	NUTS_PASS(nng_socket_get_recv_poll_fd(sub, &fd));
@@ -325,19 +325,11 @@ test_sub_recv_buf_option(void)
 static void
 test_sub_subscribe_option(void)
 {
-	nng_socket  sub;
-	size_t      sz;
-	int         v;
-	const char *opt = NNG_OPT_SUB_SUBSCRIBE;
-
+	nng_socket sub;
 	NUTS_PASS(nng_sub0_open(&sub));
 
-	NUTS_PASS(nng_socket_set(sub, opt, "abc", 3));
-	NUTS_PASS(nng_socket_set(sub, opt, "abc", 3)); // duplicate
-	NUTS_PASS(nng_socket_set_bool(sub, opt, false));
-	NUTS_PASS(nng_socket_set_int(sub, opt, 32));
-	sz = sizeof(v);
-	NUTS_FAIL(nng_socket_get(sub, opt, &v, &sz), NNG_EWRITEONLY);
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "abc", 3));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "abc", 3)); // duplicate
 
 	NUTS_CLOSE(sub);
 }
@@ -345,23 +337,14 @@ test_sub_subscribe_option(void)
 static void
 test_sub_unsubscribe_option(void)
 {
-	nng_socket  sub;
-	size_t      sz;
-	int         v;
-	const char *opt1 = NNG_OPT_SUB_SUBSCRIBE;
-	const char *opt2 = NNG_OPT_SUB_UNSUBSCRIBE;
+	nng_socket sub;
 
 	NUTS_PASS(nng_sub0_open(&sub));
 
-	NUTS_PASS(nng_socket_set(sub, opt1, "abc", 3));
-	NUTS_FAIL(nng_socket_set(sub, opt2, "abc123", 6), NNG_ENOENT);
-	NUTS_PASS(nng_socket_set(sub, opt2, "abc", 3));
-	NUTS_FAIL(nng_socket_set(sub, opt2, "abc", 3), NNG_ENOENT);
-	NUTS_PASS(nng_socket_set_int(sub, opt1, 32));
-	NUTS_FAIL(nng_socket_set_int(sub, opt2, 23), NNG_ENOENT);
-	NUTS_PASS(nng_socket_set_int(sub, opt2, 32));
-	sz = sizeof(v);
-	NUTS_FAIL(nng_socket_get(sub, opt2, &v, &sz), NNG_EWRITEONLY);
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "abc", 3));
+	NUTS_FAIL(nng_sub0_socket_unsubscribe(sub, "abc123", 6), NNG_ENOENT);
+	NUTS_PASS(nng_sub0_socket_unsubscribe(sub, "abc", 3));
+	NUTS_FAIL(nng_sub0_socket_unsubscribe(sub, "abc", 3), NNG_ENOENT);
 
 	NUTS_CLOSE(sub);
 }
@@ -403,7 +386,7 @@ test_sub_drop_new(void)
 	NUTS_PASS(nng_pub0_open(&pub));
 	NUTS_PASS(nng_socket_set_int(sub, NNG_OPT_RECVBUF, 2));
 	NUTS_PASS(nng_socket_set_bool(sub, NNG_OPT_SUB_PREFNEW, false));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, NULL, 0));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, NULL, 0));
 	NUTS_PASS(nng_socket_set_ms(sub, NNG_OPT_RECVTIMEO, 200));
 	NUTS_PASS(nng_socket_set_ms(pub, NNG_OPT_SENDTIMEO, 1000));
 	NUTS_MARRY(pub, sub);
@@ -429,7 +412,7 @@ test_sub_drop_old(void)
 	NUTS_PASS(nng_pub0_open(&pub));
 	NUTS_PASS(nng_socket_set_int(sub, NNG_OPT_RECVBUF, 2));
 	NUTS_PASS(nng_socket_set_bool(sub, NNG_OPT_SUB_PREFNEW, true));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, NULL, 0));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, NULL, 0));
 	NUTS_PASS(nng_socket_set_ms(sub, NNG_OPT_RECVTIMEO, 200));
 	NUTS_PASS(nng_socket_set_ms(pub, NNG_OPT_SENDTIMEO, 1000));
 	NUTS_MARRY(pub, sub);
@@ -459,10 +442,10 @@ test_sub_filter(void)
 	NUTS_PASS(nng_socket_set_int(sub, NNG_OPT_RECVBUF, 10));
 
 	// Set up some default filters
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "abc", 3));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "def", 3));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "ghi", 3));
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_SUBSCRIBE, "jkl", 3));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "abc", 3));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "def", 3));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "ghi", 3));
+	NUTS_PASS(nng_sub0_socket_subscribe(sub, "jkl", 3));
 
 	NUTS_MARRY(pub, sub);
 
@@ -474,7 +457,7 @@ test_sub_filter(void)
 	NUTS_PASS(nng_send(pub, "jkl-mno", 6, 0));
 
 	NUTS_SLEEP(100);
-	NUTS_PASS(nng_socket_set(sub, NNG_OPT_SUB_UNSUBSCRIBE, "ghi", 3));
+	NUTS_PASS(nng_sub0_socket_unsubscribe(sub, "ghi", 3));
 	sz = sizeof(buf);
 	NUTS_PASS(nng_recv(sub, buf, &sz, 0));
 	NUTS_TRUE(sz == 3);
@@ -512,11 +495,11 @@ test_sub_multi_context(void)
 	NUTS_PASS(nng_ctx_open(&c1, sub));
 	NUTS_PASS(nng_ctx_open(&c2, sub));
 
-	NUTS_PASS(nng_ctx_set(c1, NNG_OPT_SUB_SUBSCRIBE, "one", 3));
-	NUTS_PASS(nng_ctx_set(c1, NNG_OPT_SUB_SUBSCRIBE, "all", 3));
+	NUTS_PASS(nng_sub0_ctx_subscribe(c1, "one", 3));
+	NUTS_PASS(nng_sub0_ctx_subscribe(c1, "all", 3));
 
-	NUTS_PASS(nng_ctx_set(c2, NNG_OPT_SUB_SUBSCRIBE, "two", 3));
-	NUTS_PASS(nng_ctx_set(c2, NNG_OPT_SUB_SUBSCRIBE, "all", 3));
+	NUTS_PASS(nng_sub0_ctx_subscribe(c2, "two", 3));
+	NUTS_PASS(nng_sub0_ctx_subscribe(c2, "all", 3));
 
 	nng_aio_set_timeout(aio1, 100);
 	nng_aio_set_timeout(aio2, 100);
diff --git a/src/sp/protocol/pubsub0/xsub_test.c b/src/sp/protocol/pubsub0/xsub_test.c
index eec73505..fdbc5632 100644
--- a/src/sp/protocol/pubsub0/xsub_test.c
+++ b/src/sp/protocol/pubsub0/xsub_test.c
@@ -7,7 +7,8 @@
 // found online at https://opensource.org/licenses/MIT.
 //
 
-#include "nng/nng.h"
+#include <nng/nng.h>
+#include <nng/protocol/pubsub0/sub.h>
 #include <nuts.h>
 
 static void
@@ -257,22 +258,20 @@ test_xsub_recv_buf_option(void)
 static void
 test_xsub_subscribe_option(void)
 {
-	nng_socket  sub;
-	const char *opt = NNG_OPT_SUB_SUBSCRIBE;
+	nng_socket sub;
 
 	NUTS_PASS(nng_sub0_open_raw(&sub));
-	NUTS_FAIL(nng_socket_set(sub, opt, "abc", 3), NNG_ENOTSUP);
+	NUTS_FAIL(nng_sub0_socket_subscribe(sub, "abc", 3), NNG_ENOTSUP);
 	NUTS_CLOSE(sub);
 }
 
 static void
 test_xsub_unsubscribe_option(void)
 {
-	nng_socket  sub;
-	const char *opt = NNG_OPT_SUB_UNSUBSCRIBE;
+	nng_socket sub;
 
 	NUTS_PASS(nng_sub0_open_raw(&sub));
-	NUTS_FAIL(nng_socket_set(sub, opt, "abc", 3), NNG_ENOTSUP);
+	NUTS_FAIL(nng_sub0_socket_unsubscribe(sub, "abc", 3), NNG_ENOTSUP);
 	NUTS_CLOSE(sub);
 }
 
diff --git a/src/tools/nngcat/nngcat.c b/src/tools/nngcat/nngcat.c
index bdf6823c..da3bd6d6 100644
--- a/src/tools/nngcat/nngcat.c
+++ b/src/tools/nngcat/nngcat.c
@@ -1065,8 +1065,7 @@ main(int ac, char **av)
 	}
 
 	for (struct topic *t = topics; t != NULL; t = t->next) {
-		rv = nng_socket_set(
-		    sock, NNG_OPT_SUB_SUBSCRIBE, t->val, strlen(t->val));
+		rv = nng_sub0_socket_subscribe(sock, t->val, strlen(t->val));
 		if (rv != 0) {
 			fatal("Unable to subscribe to topic %s: %s", t->val,
 			    nng_strerror(rv));
diff --git a/src/tools/perf/pubdrop.c b/src/tools/perf/pubdrop.c
index 0e493116..27d7802a 100644
--- a/src/tools/perf/pubdrop.c
+++ b/src/tools/perf/pubdrop.c
@@ -206,7 +206,7 @@ sub_client(void *arg)
 	if ((rv = nng_socket_set_ms(sock, NNG_OPT_RECONNMINT, 51)) != 0) {
 		die("setopt: %s", nng_strerror(rv));
 	}
-	if ((rv = nng_socket_set(sock, NNG_OPT_SUB_SUBSCRIBE, "", 0)) != 0) {
+	if ((rv = nng_sub0_socket_subscribe(sock, "", 0)) != 0) {
 		die("setopt: %s", nng_strerror(rv));
 	}
 	if ((rv = nng_socket_set_ms(sock, NNG_OPT_RECVTIMEO, 10000)) != 0) {
diff --git a/tests/multistress.c b/tests/multistress.c
index e58b94d7..b9e48014 100644
--- a/tests/multistress.c
+++ b/tests/multistress.c
@@ -581,7 +581,7 @@ pubsub0_test(int ntests)
 		if ((rv = nng_aio_alloc(&cli->recd, sub0_recd, cli)) != 0) {
 			fatal("nng_aio_alloc", rv);
 		}
-		rv = nng_socket_set(cli->sock, NNG_OPT_SUB_SUBSCRIBE, "", 0);
+		rv = nng_sub0_socket_subscribe(cli->sock, "", 0);
 		if (rv != 0) {
 			fatal("subscribe", rv);
 		}