From owner-freebsd-bugs@FreeBSD.ORG Sun Jan 23 02:20:25 2005 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3646B16A4CE for ; Sun, 23 Jan 2005 02:20:25 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id F331A43D1D for ; Sun, 23 Jan 2005 02:20:24 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.1/8.13.1) with ESMTP id j0N2KOXK020213 for ; Sun, 23 Jan 2005 02:20:24 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.1/8.13.1/Submit) id j0N2KOHQ020212; Sun, 23 Jan 2005 02:20:24 GMT (envelope-from gnats) Date: Sun, 23 Jan 2005 02:20:24 GMT Message-Id: <200501230220.j0N2KOHQ020212@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Maxim Konovalov Subject: Re: bin/76075: arp program failures due to ARP table growth X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Maxim Konovalov List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Jan 2005 02:20:25 -0000 The following reply was made to PR bin/76075; it has been noted by GNATS. From: Maxim Konovalov To: Dmitrij Tejblum Cc: bug-followup@freebsd.org Subject: Re: bin/76075: arp program failures due to ARP table growth Date: Sun, 23 Jan 2005 05:16:35 +0300 (MSK) [...] > >Description: > > The arp -an command sometimes fail with > > arp: actual retrieval of routing table: Cannot allocate memory > > if ARP tables has been grown after its size was estimated. > > >How-To-Repeat: > >Fix: > > Allocate a bit more memory for ARP table, so the event will be less likely. > > > --- arp.c Tue Jan 11 02:00:45 2005 > +++ arp.c Tue Jan 11 02:05:15 2005 > @@ -471,10 +471,11 @@ > mib[5] = RTF_LLINFO; > if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) > err(1, "route-sysctl-estimate"); > if (needed == 0) /* empty table */ > return 0; > + needed += needed / 2; > if ((buf = malloc(needed)) == NULL) > err(1, "malloc"); > if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) > err(1, "actual retrieval of routing table"); > lim = buf + needed; What is your opinion about an enclosed diff (a bit more adaptable algorithm stolen from killall(1))? Index: arp.c =================================================================== RCS file: /home/ncvs/src/usr.sbin/arp/arp.c,v retrieving revision 1.54 diff -u -r1.54 arp.c --- arp.c 24 Dec 2004 22:16:38 -0000 1.54 +++ arp.c 23 Jan 2005 02:14:10 -0000 @@ -456,12 +456,12 @@ { int mib[6]; size_t needed; - char *lim, *buf, *next; + char *lim, *buf, *newbuf, *next; struct rt_msghdr *rtm; struct sockaddr_inarp *sin2; struct sockaddr_dl *sdl; char ifname[IF_NAMESIZE]; - int found_entry = 0; + int st, found_entry = 0; mib[0] = CTL_NET; mib[1] = PF_ROUTE; @@ -475,7 +475,19 @@ return 0; if ((buf = malloc(needed)) == NULL) err(1, "malloc"); - if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) + st = sysctl(mib, 6, NULL, &needed, NULL, 0); + do { + needed += needed / 2; + newbuf = realloc(buf, needed); + if (newbuf == NULL) { + if (buf != NULL) + free(buf); + errx(1, "could not reallocate memory"); + } + buf = newbuf; + st = sysctl(mib, 6, buf, &needed, NULL, 0); + } while (st == -1 && errno == ENOMEM); + if (st == -1) err(1, "actual retrieval of routing table"); lim = buf + needed; for (next = buf; next < lim; next += rtm->rtm_msglen) { %%% -- Maxim Konovalov