From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: bgpd: increase ibuf message size to 128k
To: tech@openbsd.org
Date: Mon, 2 Dec 2024 14:57:01 +0100

To support extended bgp messages of up to 65k bump the maximum imsg size
to 128k on all channels.

On top of this remove the READ_BUF_SIZE define and replace its only use
with IBUF_READ_SIZE since the MAX_SOCK_BUF is used to scale up the imsg
socketpairs.

-- 
:wq Claudio

Index: bgpctl/bgpctl.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpctl/bgpctl.c,v
diff -u -p -r1.311 bgpctl.c
--- bgpctl/bgpctl.c	21 Nov 2024 13:38:14 -0000	1.311
+++ bgpctl/bgpctl.c	2 Dec 2024 13:54:23 -0000
@@ -176,7 +176,8 @@ main(int argc, char *argv[])
 
 	if ((imsgbuf = malloc(sizeof(struct imsgbuf))) == NULL)
 		err(1, NULL);
-	if (imsgbuf_init(imsgbuf, fd) == -1)
+	if (imsgbuf_init(imsgbuf, fd) == -1 ||
+	    imsgbuf_set_maxsize(imsgbuf, MAX_BGPD_IMSGSIZE) == -1)
 		err(1, NULL);
 	done = 0;
 
Index: bgpd/bgpd.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/bgpd.c,v
diff -u -p -r1.277 bgpd.c
--- bgpd/bgpd.c	21 Nov 2024 13:38:14 -0000	1.277
+++ bgpd/bgpd.c	2 Dec 2024 13:54:23 -0000
@@ -277,8 +277,11 @@ main(int argc, char *argv[])
 	    (ibuf_rtr = malloc(sizeof(struct imsgbuf))) == NULL)
 		fatal(NULL);
 	if (imsgbuf_init(ibuf_se, pipe_m2s[0]) == -1 ||
+	    imsgbuf_set_maxsize(ibuf_se, MAX_BGPD_IMSGSIZE) == -1 ||
 	    imsgbuf_init(ibuf_rde, pipe_m2r[0]) == -1 ||
-	    imsgbuf_init(ibuf_rtr, pipe_m2roa[0]) == -1)
+	    imsgbuf_set_maxsize(ibuf_rde, MAX_BGPD_IMSGSIZE) == -1 ||
+	    imsgbuf_init(ibuf_rtr, pipe_m2roa[0]) == -1 ||
+	    imsgbuf_set_maxsize(ibuf_rtr, MAX_BGPD_IMSGSIZE) == -1)
 		fatal(NULL);
 	imsgbuf_allow_fdpass(ibuf_se);
 	imsgbuf_allow_fdpass(ibuf_rde);
Index: bgpd/bgpd.h
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/bgpd.h,v
diff -u -p -r1.500 bgpd.h
--- bgpd/bgpd.h	21 Nov 2024 13:29:52 -0000	1.500
+++ bgpd/bgpd.h	2 Dec 2024 13:54:23 -0000
@@ -50,8 +50,8 @@
 
 #define	MAX_PKTSIZE			4096
 #define	MIN_HOLDTIME			3
-#define	READ_BUF_SIZE			65535
-#define	MAX_SOCK_BUF			(4 * READ_BUF_SIZE)
+#define	MAX_BGPD_IMSGSIZE		(128 * 1024)
+#define	MAX_SOCK_BUF			(4 * IBUF_READ_SIZE)
 #define	RT_BUF_SIZE			16384
 #define	MAX_RTSOCK_BUF			(2 * 1024 * 1024)
 #define	MAX_COMM_MATCH			3
Index: bgpd/control.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/control.c,v
diff -u -p -r1.131 control.c
--- bgpd/control.c	21 Nov 2024 13:38:14 -0000	1.131
+++ bgpd/control.c	2 Dec 2024 13:54:23 -0000
@@ -180,8 +180,10 @@ control_accept(int listenfd, int restric
 		return (0);
 	}
 
-	if (imsgbuf_init(&ctl_conn->imsgbuf, connfd) == -1) {
+	if (imsgbuf_init(&ctl_conn->imsgbuf, connfd) == -1 ||
+	    imsgbuf_set_maxsize(&ctl_conn->imsgbuf, MAX_BGPD_IMSGSIZE) == -1) {
 		log_warn("control_accept");
+		imsgbuf_clear(&ctl_conn->imsgbuf);
 		close(connfd);
 		free(ctl_conn);
 		return (0);
Index: bgpd/rde.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde.c,v
diff -u -p -r1.641 rde.c
--- bgpd/rde.c	2 Dec 2024 13:46:11 -0000	1.641
+++ bgpd/rde.c	2 Dec 2024 13:54:23 -0000
@@ -201,7 +201,8 @@ rde_main(int debug, int verbose)
 
 	if ((ibuf_main = malloc(sizeof(struct imsgbuf))) == NULL)
 		fatal(NULL);
-	if (imsgbuf_init(ibuf_main, 3) == -1)
+	if (imsgbuf_init(ibuf_main, 3) == -1 ||
+	    imsgbuf_set_maxsize(ibuf_main, MAX_BGPD_IMSGSIZE) == -1)
 		fatal(NULL);
 	imsgbuf_allow_fdpass(ibuf_main);
 
@@ -844,7 +845,8 @@ rde_dispatch_imsg_parent(struct imsgbuf 
 			}
 			if ((i = malloc(sizeof(struct imsgbuf))) == NULL)
 				fatal(NULL);
-			if (imsgbuf_init(i, fd) == -1)
+			if (imsgbuf_init(i, fd) == -1 ||
+			    imsgbuf_set_maxsize(i, MAX_BGPD_IMSGSIZE) == -1)
 				fatal(NULL);
 			switch (imsg_get_type(&imsg)) {
 			case IMSG_SOCKET_CONN:
Index: bgpd/rtr.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rtr.c,v
diff -u -p -r1.27 rtr.c
--- bgpd/rtr.c	21 Nov 2024 13:38:14 -0000	1.27
+++ bgpd/rtr.c	2 Dec 2024 13:54:23 -0000
@@ -219,7 +219,8 @@ rtr_main(int debug, int verbose)
 
 	if ((ibuf_main = malloc(sizeof(struct imsgbuf))) == NULL)
 		fatal(NULL);
-	if (imsgbuf_init(ibuf_main, 3) == -1)
+	if (imsgbuf_init(ibuf_main, 3) == -1 ||
+	    imsgbuf_set_maxsize(ibuf_main, MAX_BGPD_IMSGSIZE) == -1)
 		fatal(NULL);
 	imsgbuf_allow_fdpass(ibuf_main);
 
@@ -338,7 +339,9 @@ rtr_dispatch_imsg_parent(struct imsgbuf 
 			}
 			if ((ibuf_rde = malloc(sizeof(struct imsgbuf))) == NULL)
 				fatal(NULL);
-			if (imsgbuf_init(ibuf_rde, fd) == -1)
+			if (imsgbuf_init(ibuf_rde, fd) == -1 ||
+			    imsgbuf_set_maxsize(ibuf_rde, MAX_BGPD_IMSGSIZE) ==
+			    -1)
 				fatal(NULL);
 			break;
 		case IMSG_SOCKET_SETUP:
Index: bgpd/session.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/session.c,v
diff -u -p -r1.499 session.c
--- bgpd/session.c	26 Nov 2024 13:59:54 -0000	1.499
+++ bgpd/session.c	2 Dec 2024 13:54:24 -0000
@@ -240,7 +240,8 @@ session_main(int debug, int verbose)
 
 	if ((ibuf_main = malloc(sizeof(struct imsgbuf))) == NULL)
 		fatal(NULL);
-	if (imsgbuf_init(ibuf_main, 3) == -1)
+	if (imsgbuf_init(ibuf_main, 3) == -1 ||
+	    imsgbuf_set_maxsize(ibuf_main, MAX_BGPD_IMSGSIZE) == -1)
 		fatal(NULL);
 	imsgbuf_allow_fdpass(ibuf_main);
 
@@ -2851,7 +2852,8 @@ session_dispatch_imsg(struct imsgbuf *im
 			}
 			if ((i = malloc(sizeof(struct imsgbuf))) == NULL)
 				fatal(NULL);
-			if (imsgbuf_init(i, fd) == -1)
+			if (imsgbuf_init(i, fd) == -1 ||
+			    imsgbuf_set_maxsize(i, MAX_BGPD_IMSGSIZE) == -1)
 				fatal(NULL);
 			if (imsg_get_type(&imsg) == IMSG_SOCKET_CONN) {
 				if (ibuf_rde) {