Author: eugen Date: Wed Jul 18 01:57:13 2018 New Revision: 336440 URL: https://svnweb.freebsd.org/changeset/base/336440
Log: MFC r336195: unbreak dhclient(8) option 26 processing Make dhclient(8) verify if new MTU (option 26) differs from current one and skip unneeded MTU change. This check eliminates infinite loop of MTU change / link flap / lease verification / MTU change / link flap etc. in case of some NIC drivers like em(4) or igb(4). PR: 229432 Approved by: mav (mentor) Modified: stable/11/sbin/dhclient/dispatch.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sbin/dhclient/dispatch.c ============================================================================== --- stable/11/sbin/dhclient/dispatch.c Wed Jul 18 00:56:25 2018 (r336439) +++ stable/11/sbin/dhclient/dispatch.c Wed Jul 18 01:57:13 2018 (r336440) @@ -545,17 +545,29 @@ interface_set_mtu_priv(char *ifname, u_int16_t mtu) { struct ifreq ifr; int sock; + u_int16_t old_mtu; if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) error("Can't create socket"); memset(&ifr, 0, sizeof(ifr)); + old_mtu = 0; strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); - ifr.ifr_mtu = mtu; - if (ioctl(sock, SIOCSIFMTU, &ifr) == -1) - warning("SIOCSIFMTU failed (%d): %s", mtu, + if (ioctl(sock, SIOCGIFMTU, (caddr_t)&ifr) == -1) + warning("SIOCGIFMTU failed (%s): %s", ifname, strerror(errno)); + else + old_mtu = ifr.ifr_mtu; + + if (mtu != old_mtu) { + ifr.ifr_mtu = mtu; + + if (ioctl(sock, SIOCSIFMTU, &ifr) == -1) + warning("SIOCSIFMTU failed (%d): %s", mtu, + strerror(errno)); + } + close(sock); } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"