From owner-svn-src-all@freebsd.org Tue Apr 30 14:44:40 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 91F411593FBE; Tue, 30 Apr 2019 14:44:40 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3991A751DA; Tue, 30 Apr 2019 14:44:40 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 29F48B0EF; Tue, 30 Apr 2019 14:44:40 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x3UEieB5088108; Tue, 30 Apr 2019 14:44:40 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x3UEieAU088107; Tue, 30 Apr 2019 14:44:40 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201904301444.x3UEieAU088107@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Tue, 30 Apr 2019 14:44:40 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r346960 - head/usr.sbin/rtadvd X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/usr.sbin/rtadvd X-SVN-Commit-Revision: 346960 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 3991A751DA X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.98 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.98)[-0.977,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Apr 2019 14:44:40 -0000 Author: markj Date: Tue Apr 30 14:44:39 2019 New Revision: 346960 URL: https://svnweb.freebsd.org/changeset/base/346960 Log: Retry upon NET_RT_IFLIST sysctl failure. Port the logic used by getifaddrs(3) to handle the case where NET_RT_IFLIST returns ENOMEM, which can occur if the list size changes between the buffer allocation and sysctl read. PR: 195191 Submitted by: Guy Yur (original version) MFC after: 1 week Modified: head/usr.sbin/rtadvd/if.c Modified: head/usr.sbin/rtadvd/if.c ============================================================================== --- head/usr.sbin/rtadvd/if.c Tue Apr 30 14:29:09 2019 (r346959) +++ head/usr.sbin/rtadvd/if.c Tue Apr 30 14:44:39 2019 (r346960) @@ -408,6 +408,8 @@ update_ifinfo_nd_flags(struct ifinfo *ifi) return (0); } +#define MAX_SYSCTL_TRY 5 + struct ifinfo * update_ifinfo(struct ifilist_head_t *ifi_head, int ifindex) { @@ -419,26 +421,43 @@ update_ifinfo(struct ifilist_head_t *ifi_head, int ifi size_t len; char *lim; int mib[] = { CTL_NET, PF_ROUTE, 0, AF_INET6, NET_RT_IFLIST, 0 }; - int error; + int error, ntry; syslog(LOG_DEBUG, "<%s> enter", __func__); - if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), NULL, &len, NULL, 0) < - 0) { - syslog(LOG_ERR, - "<%s> sysctl: NET_RT_IFLIST size get failed", __func__); - exit(1); - } - if ((msg = malloc(len)) == NULL) { - syslog(LOG_ERR, "<%s> malloc failed", __func__); - exit(1); - } - if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), msg, &len, NULL, 0) < - 0) { - syslog(LOG_ERR, - "<%s> sysctl: NET_RT_IFLIST get failed", __func__); - exit(1); - } + ntry = 0; + do { + /* + * We'll try to get addresses several times in case that + * the number of addresses is unexpectedly increased during + * the two sysctl calls. This should rarely happen. + * Portability note: since FreeBSD does not add margin of + * memory at the first sysctl, the possibility of failure on + * the second sysctl call is a bit higher. + */ + + if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) < 0) { + syslog(LOG_ERR, + "<%s> sysctl: NET_RT_IFLIST size get failed", + __func__); + exit(1); + } + if ((msg = malloc(len)) == NULL) { + syslog(LOG_ERR, "<%s> malloc failed", __func__); + exit(1); + } + if (sysctl(mib, nitems(mib), msg, &len, NULL, 0) < 0) { + if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { + free(msg); + syslog(LOG_ERR, + "<%s> sysctl: NET_RT_IFLIST get failed", + __func__); + exit(1); + } + free(msg); + msg = NULL; + } + } while (msg == NULL); lim = msg + len; for (ifm = (struct if_msghdr *)msg;