bfdd,lib: implement protocol profile selection

Implement the infrastructure for other protocols daemon (e.g. `bgpd`,
`ospfd`, `isisd` etc...) to communicate to BFD daemon which profile
they want to use with their peers.

It was also added the ability for protocols to change profile while
running (no need to remove the registration and then register again).

The protocols message building function was rewritten to support
multiple arguments through `struct bfd_session_arg`, so we can
implement new features without the need of changing function
prototypes. The old function was also rewritten to keep
compatibility.

The profile message part is only available for BFD daemon at the
moment.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

1 files changed, 116 insertions, 83 deletions

diff --git a/lib/bfd.c b/lib/bfd.c
index 5f2d2f0ed..2d86acbbf 100644
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -127,9 +127,8 @@ void bfd_peer_sendmsg(struct zclient *zclient, struct bfd_info *bfd_info,
 		      int ttl, int multihop, int cbit, int command,
 		      int set_flag, vrf_id_t vrf_id)
 {
-	struct stream *s;
-	int ret;
-	int len;
+	struct bfd_session_arg args = {};
+	size_t addrlen;
 
 	/* Individual reg/dereg messages are suppressed during shutdown. */
 	if (CHECK_FLAG(bfd_gbl.flags, BFD_GBL_FLAG_IN_SHUTDOWN)) {
@@ -150,86 +149,30 @@ void bfd_peer_sendmsg(struct zclient *zclient, struct bfd_info *bfd_info,
 		return;
 	}
 
-	s = zclient->obuf;
-	stream_reset(s);
-	zclient_create_header(s, command, vrf_id);
-
-	stream_putl(s, getpid());
-
-	stream_putw(s, family);
-	switch (family) {
-	case AF_INET:
-		stream_put_in_addr(s, (struct in_addr *)dst_ip);
-		break;
-	case AF_INET6:
-		stream_put(s, dst_ip, 16);
-		break;
-	default:
-		break;
-	}
-
-	if (command != ZEBRA_BFD_DEST_DEREGISTER) {
-		stream_putl(s, bfd_info->required_min_rx);
-		stream_putl(s, bfd_info->desired_min_tx);
-		stream_putc(s, bfd_info->detect_mult);
-	}
-
-	if (multihop) {
-		stream_putc(s, 1);
-		/* Multi-hop destination send the source IP address to BFD */
-		if (src_ip) {
-			stream_putw(s, family);
-			switch (family) {
-			case AF_INET:
-				stream_put_in_addr(s, (struct in_addr *)src_ip);
-				break;
-			case AF_INET6:
-				stream_put(s, src_ip, 16);
-				break;
-			default:
-				break;
-			}
-		}
-		stream_putc(s, ttl);
-	} else {
-		stream_putc(s, 0);
-		if ((family == AF_INET6) && (src_ip)) {
-			stream_putw(s, family);
-			stream_put(s, src_ip, 16);
-		}
-		if (if_name) {
-			len = strlen(if_name);
-			stream_putc(s, len);
-			stream_put(s, if_name, len);
-		} else {
-			stream_putc(s, 0);
-		}
-	}
-	/* cbit */
-	if (cbit)
-		stream_putc(s, 1);
-	else
-		stream_putc(s, 0);
-
-	stream_putw_at(s, 0, stream_get_endp(s));
-
-	ret = zclient_send_message(zclient);
-
-	if (ret < 0) {
-		if (bfd_debug)
-			zlog_debug(
-				"bfd_peer_sendmsg: zclient_send_message() failed");
-		return;
-	}
-
-	if (set_flag) {
-		if (command == ZEBRA_BFD_DEST_REGISTER)
-			SET_FLAG(bfd_info->flags, BFD_FLAG_BFD_REG);
-		else if (command == ZEBRA_BFD_DEST_DEREGISTER)
-			UNSET_FLAG(bfd_info->flags, BFD_FLAG_BFD_REG);
-	}
-
-	return;
+	/* Fill in all arguments. */
+	args.ttl = ttl;
+	args.cbit = cbit;
+	args.family = family;
+	args.mhop = multihop;
+	args.vrf_id = vrf_id;
+	args.command = command;
+	args.set_flag = set_flag;
+	args.bfd_info = bfd_info;
+	args.min_rx = bfd_info->required_min_rx;
+	args.min_tx = bfd_info->desired_min_tx;
+	args.detection_multiplier = bfd_info->detect_mult;
+
+	addrlen = family == AF_INET ? sizeof(struct in_addr)
+				    : sizeof(struct in6_addr);
+	memcpy(&args.dst, dst_ip, addrlen);
+	if (src_ip)
+		memcpy(&args.src, src_ip, addrlen);
+
+	if (if_name)
+		args.ifnamelen =
+			strlcpy(args.ifname, if_name, sizeof(args.ifname));
+
+	zclient_bfd_command(zclient, &args);
 }
 
 /*
@@ -478,3 +421,93 @@ void bfd_client_sendmsg(struct zclient *zclient, int command,
 
 	return;
 }
+
+int zclient_bfd_command(struct zclient *zc, struct bfd_session_arg *args)
+{
+	struct stream *s;
+	size_t addrlen;
+
+	/* Check socket. */
+	if (!zc || zc->sock < 0) {
+		if (bfd_debug)
+			zlog_debug("%s: zclient unavailable", __func__);
+		return -1;
+	}
+
+	s = zc->obuf;
+	stream_reset(s);
+
+	/* Create new message. */
+	zclient_create_header(s, args->command, args->vrf_id);
+	stream_putl(s, getpid());
+
+	/* Encode destination address. */
+	stream_putw(s, args->family);
+	addrlen = (args->family == AF_INET) ? sizeof(struct in_addr)
+					    : sizeof(struct in6_addr);
+	stream_put(s, &args->dst, addrlen);
+
+	/* Encode timers if this is a registration message. */
+	if (args->command != ZEBRA_BFD_DEST_DEREGISTER) {
+		stream_putl(s, args->min_rx);
+		stream_putl(s, args->min_tx);
+		stream_putc(s, args->detection_multiplier);
+	}
+
+	if (args->mhop) {
+		/* Multi hop indicator. */
+		stream_putc(s, 1);
+
+		/* Multi hop always sends the source address. */
+		stream_putw(s, args->family);
+		stream_put(s, &args->src, addrlen);
+
+		/* Send the expected TTL. */
+		stream_putc(s, args->ttl);
+	} else {
+		/* Multi hop indicator. */
+		stream_putc(s, 0);
+
+		/* Single hop only sends the source address when IPv6. */
+		if (args->family == AF_INET6) {
+			stream_putw(s, args->family);
+			stream_put(s, &args->src, addrlen);
+		}
+
+		/* Send interface name if any. */
+		stream_putc(s, args->ifnamelen);
+		if (args->ifnamelen)
+			stream_put(s, args->ifname, args->ifnamelen);
+	}
+
+	/* Send the C bit indicator. */
+	stream_putc(s, args->cbit);
+
+	/* `ptm-bfd` doesn't support profiles yet. */
+#if HAVE_BFDD > 0
+	/* Send profile name if any. */
+	stream_putc(s, args->profilelen);
+	if (args->profilelen)
+		stream_put(s, args->profile, args->profilelen);
+#endif /* HAVE_BFDD */
+
+	/* Finish the message by writing the size. */
+	stream_putw_at(s, 0, stream_get_endp(s));
+
+	/* Send message to zebra. */
+	if (zclient_send_message(zc) == -1) {
+		if (bfd_debug)
+			zlog_debug("%s: zclient_send_message failed", __func__);
+		return -1;
+	}
+
+	/* Write registration indicator into data structure. */
+	if (args->set_flag) {
+		if (args->command == ZEBRA_BFD_DEST_REGISTER)
+			SET_FLAG(args->bfd_info->flags, BFD_FLAG_BFD_REG);
+		else if (args->command == ZEBRA_BFD_DEST_DEREGISTER)
+			UNSET_FLAG(args->bfd_info->flags, BFD_FLAG_BFD_REG);
+	}
+
+	return 0;
+}