From 4f4539e776640bc1e7d04af3f0a0b3af4b75bfcd Mon Sep 17 00:00:00 2001
From: Eugene Crosser <crosser@average.org>
Date: Wed, 13 Mar 2019 23:24:47 +0100
Subject: [PATCH] rudimentary subscribe/unsubscribe

---
 examples/psmb.c   |  4 +++-
 include/psmb.h    |  6 +++++-
 src/psmb_priv.h   |  1 +
 src/psmb_socket.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/examples/psmb.c b/examples/psmb.c
index 2f0d6ea..8637a0b 100644
--- a/examples/psmb.c
+++ b/examples/psmb.c
@@ -20,6 +20,8 @@ int main(int argc, char *argv[], char *envp[])
 	printf("created psmb at %p\n", ctx);
 	res = psmb_set_logf(ctx, logprt, NULL);
 	res = psmb_open(ctx);
+	res = psmb_subscribe(ctx, "test-channel");
+	res = psmb_unsubscribe(ctx, "test-channel");
 	psmb_destroy(ctx);
-	return 0;
+	return psmb_success(res);
 }
diff --git a/include/psmb.h b/include/psmb.h
index 022d5b8..c5869ec 100644
--- a/include/psmb.h
+++ b/include/psmb.h
@@ -21,14 +21,18 @@ psmb_result_t psmb_set_mgrp(psmb_ctx_t *ctx, struct in6_addr prefix,
 psmb_result_t psmb_open(psmb_ctx_t *ctx);
 void psmb_destroy(psmb_ctx_t *ctx);
 int psmb_getfd(psmb_ctx_t *ctx);
+bool psmb_success(psmb_result_t result);
+bool psmb_message_waiting(psmb_result_t result);
 bool psmb_need_write_wait(psmb_result_t result);
 psmb_result_t psmb_ev_rd(psmb_ctx_t *ctx);
 psmb_result_t psmb_ev_wr(psmb_ctx_t *ctx);
 psmb_result_t psmb_ev_ex(psmb_ctx_t *ctx);
 psmb_result_t psmb_subscribe(psmb_ctx_t *ctx, char *channel);
+psmb_result_t psmb_unsubscribe(psmb_ctx_t *ctx, char *channel);
 psmb_result_t psmb_publish(psmb_ctx_t *ctx, char *channel,
 	void *data, size_t size);
-bool psmb_message(psmb_ctx_t *ctx, char **channel,
+psmb_result_t psmb_get_message(psmb_ctx_t *ctx, char **channel,
 	void **data, size_t *size);
+psmb_result_t psmb_acknowledge(psmb_ctx_t *ctx);
 
 #endif
diff --git a/src/psmb_priv.h b/src/psmb_priv.h
index 5e3c2ad..c80ae62 100644
--- a/src/psmb_priv.h
+++ b/src/psmb_priv.h
@@ -7,6 +7,7 @@
 #define PSMB_OK		0
 #define PSMB_ERROR	1
 #define PSMB_NEED_WRITE	2
+#define PSMB_MESSAGE	4
 
 #define PSMB_DEFAULT_PORT 5313
 #define PSMB_DEFAULT_PMTU 1452
diff --git a/src/psmb_socket.c b/src/psmb_socket.c
index 538b87c..06b90a8 100644
--- a/src/psmb_socket.c
+++ b/src/psmb_socket.c
@@ -31,6 +31,11 @@ psmb_ctx_t *psmb_new_mm(void *(*malloc)(size_t size),
 		.fd = -1,
 		.malloc = malloc, .free = free, .realloc = realloc,
 		.logf = dummy_log,
+		.prefix = (struct in6_addr){{{	0xff, 0xff, 0x01, 0x05,
+						0xb0, 0x55, 0xff, 0xe7,
+						0x00, 0x00, 0x00, 0x00,
+						0x00, 0x00, 0x00, 0x00 }}},
+		.prefixlen = 64,
 		.pmtu = PSMB_DEFAULT_PMTU,
 		.port = PSMB_DEFAULT_PORT};
 	return ctx;
@@ -140,6 +145,50 @@ psmb_result_t psmb_open(psmb_ctx_t *ctx)
 	return (psmb_result_t){PSMB_OK};
 }
 
+static psmb_result_t psmb_sub_unsub(psmb_ctx_t *ctx, char *channel, int option)
+{
+	struct ipv6_mreq mreq = { 0 };
+
+	if (ctx->fd == -1) {
+		LOG(ctx, LOG_ERR, "subscribe: psmb is not open");
+		errno = EINVAL;
+		return (psmb_result_t){PSMB_ERROR};
+	}
+	mreq.ipv6mr_multiaddr = ctx->prefix; /* use hash of the channel */
+	mreq.ipv6mr_interface = 0; /* how to use this??? */
+	if (setsockopt(ctx->fd, IPPROTO_IPV6, option,
+		(void *)&mreq, sizeof(mreq)) == -1) {
+		int sverr = errno;
+		LOG(ctx, LOG_ERR, "add_membership(): %m");
+		errno = sverr;
+		return (psmb_result_t){PSMB_ERROR};
+	}
+	return (psmb_result_t){PSMB_OK};
+}
+
+psmb_result_t psmb_subscribe(psmb_ctx_t *ctx, char *channel) {
+	return psmb_sub_unsub(ctx, channel, IPV6_ADD_MEMBERSHIP);
+}
+
+psmb_result_t psmb_unsubscribe(psmb_ctx_t *ctx, char *channel) {
+	return psmb_sub_unsub(ctx, channel, IPV6_DROP_MEMBERSHIP);
+}
+
+bool psmb_success(psmb_result_t result)
+{
+	return !(result.code & PSMB_ERROR);
+}
+
+bool psmb_message_waiting(psmb_result_t result)
+{
+	return !!(result.code & PSMB_MESSAGE);
+}
+
+bool psmb_need_write_wait(psmb_result_t result)
+{
+	return !!(result.code & PSMB_NEED_WRITE);
+}
+
 void psmb_destroy(psmb_ctx_t *ctx)
 {
 	if (ctx->fd == -1) {
-- 
2.39.2