--- embedaddon/dnsmasq/src/netlink.c 2014/06/15 16:31:38 1.1.1.2 +++ embedaddon/dnsmasq/src/netlink.c 2021/03/17 00:56:46 1.1.1.4 @@ -1,4 +1,4 @@ -/* dnsmasq is Copyright (c) 2000-2014 Simon Kelley +/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -22,6 +22,15 @@ #include #include +/* Blergh. Radv does this, so that's our excuse. */ +#ifndef SOL_NETLINK +#define SOL_NETLINK 270 +#endif + +#ifndef NETLINK_NO_ENOBUFS +#define NETLINK_NO_ENOBUFS 5 +#endif + /* linux 2.6.19 buggers up the headers, patch it up here. */ #ifndef IFA_RTA # define IFA_RTA(r) \ @@ -38,12 +47,13 @@ static struct iovec iov; static u32 netlink_pid; -static int nl_async(struct nlmsghdr *h); +static void nl_async(struct nlmsghdr *h); -void netlink_init(void) +char *netlink_init(void) { struct sockaddr_nl addr; socklen_t slen = sizeof(addr); + int opt = 1; addr.nl_family = AF_NETLINK; addr.nl_pad = 0; @@ -51,11 +61,10 @@ void netlink_init(void) addr.nl_groups = RTMGRP_IPV4_ROUTE; if (option_bool(OPT_CLEVERBIND)) addr.nl_groups |= RTMGRP_IPV4_IFADDR; -#ifdef HAVE_IPV6 addr.nl_groups |= RTMGRP_IPV6_ROUTE; if (option_bool(OPT_CLEVERBIND)) addr.nl_groups |= RTMGRP_IPV6_IFADDR; -#endif + #ifdef HAVE_DHCP6 if (daemon->doing_ra || daemon->doing_dhcp6) addr.nl_groups |= RTMGRP_IPV6_IFADDR; @@ -73,14 +82,21 @@ void netlink_init(void) } if (daemon->netlinkfd == -1 || - getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == 1) + getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == -1) die(_("cannot create netlink socket: %s"), NULL, EC_MISC); - + + /* save pid assigned by bind() and retrieved by getsockname() */ netlink_pid = addr.nl_pid; iov.iov_len = 100; iov.iov_base = safe_malloc(iov.iov_len); + + if (daemon->kernel_version >= KERNEL_VERSION(2,6,30) && + setsockopt(daemon->netlinkfd, SOL_NETLINK, NETLINK_NO_ENOBUFS, &opt, sizeof(opt)) == -1) + return _("warning: failed to set NETLINK_NO_ENOBUFS on netlink socket"); + + return NULL; } static ssize_t netlink_recv(void) @@ -142,17 +158,17 @@ int iface_enumerate(int family, void *parm, int (*call struct nlmsghdr *h; ssize_t len; static unsigned int seq = 0; - int callback_ok = 1, newaddr = 0; + int callback_ok = 1; struct { struct nlmsghdr nlh; struct rtgenmsg g; } req; + memset(&req, 0, sizeof(req)); + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; - addr.nl_pad = 0; - addr.nl_groups = 0; - addr.nl_pid = 0; /* address to kernel */ again: if (family == AF_UNSPEC) @@ -169,10 +185,10 @@ int iface_enumerate(int family, void *parm, int (*call req.g.rtgen_family = family; /* Don't block in recvfrom if send fails */ - while((len = sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, - (struct sockaddr *)&addr, sizeof(addr))) == -1 && retry_send()); - - if (len == -1) + while(retry_send(sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, + (struct sockaddr *)&addr, sizeof(addr)))); + + if (errno != 0) return 0; while (1) @@ -188,24 +204,19 @@ int iface_enumerate(int family, void *parm, int (*call } for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len)) - if (h->nlmsg_seq != seq || h->nlmsg_pid != netlink_pid || h->nlmsg_type == NLMSG_ERROR) + if (h->nlmsg_pid != netlink_pid || h->nlmsg_type == NLMSG_ERROR) { /* May be multicast arriving async */ - if (nl_async(h)) - { - newaddr = 1; - enumerate_interfaces(1); /* reset */ - } + nl_async(h); } - else if (h->nlmsg_type == NLMSG_DONE) + else if (h->nlmsg_seq != seq) { - /* handle async new interface address arrivals, these have to be done - after we complete as we're not re-entrant */ - if (newaddr) - newaddress(dnsmasq_time()); - - return callback_ok; + /* May be part of incomplete response to previous request after + ENOBUFS. Drop it. */ + continue; } + else if (h->nlmsg_type == NLMSG_DONE) + return callback_ok; else if (h->nlmsg_type == RTM_NEWADDR && family != AF_UNSPEC && family != AF_LOCAL) { struct ifaddrmsg *ifa = NLMSG_DATA(h); @@ -219,7 +230,8 @@ int iface_enumerate(int family, void *parm, int (*call struct in_addr netmask, addr, broadcast; char *label = NULL; - netmask.s_addr = htonl(0xffffffff << (32 - ifa->ifa_prefixlen)); + netmask.s_addr = htonl(~(in_addr_t)0 << (32 - ifa->ifa_prefixlen)); + addr.s_addr = 0; broadcast.s_addr = 0; @@ -239,7 +251,6 @@ int iface_enumerate(int family, void *parm, int (*call if (!((*callback)(addr, ifa->ifa_index, label, netmask, broadcast, parm))) callback_ok = 0; } -#ifdef HAVE_IPV6 else if (ifa->ifa_family == AF_INET6) { struct in6_addr *addrp = NULL; @@ -274,7 +285,6 @@ int iface_enumerate(int family, void *parm, int (*call (int) preferred, (int)valid, parm))) callback_ok = 0; } -#endif } } else if (h->nlmsg_type == RTM_NEWNEIGH && family == AF_UNSPEC) @@ -298,7 +308,8 @@ int iface_enumerate(int family, void *parm, int (*call rta = RTA_NEXT(rta, len1); } - if (inaddr && mac && callback_ok) + if (!(neigh->ndm_state & (NUD_NOARP | NUD_INCOMPLETE | NUD_FAILED)) && + inaddr && mac && callback_ok) if (!((*callback)(neigh->ndm_family, inaddr, mac, maclen, parm))) callback_ok = 0; } @@ -330,11 +341,11 @@ int iface_enumerate(int family, void *parm, int (*call } } -void netlink_multicast(time_t now) +void netlink_multicast(void) { ssize_t len; struct nlmsghdr *h; - int flags, newaddr = 0; + int flags; /* don't risk blocking reading netlink messages here. */ if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 || @@ -343,24 +354,19 @@ void netlink_multicast(time_t now) if ((len = netlink_recv()) != -1) for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len)) - if (nl_async(h)) - newaddr = 1; + nl_async(h); /* restore non-blocking status */ fcntl(daemon->netlinkfd, F_SETFL, flags); - - if (newaddr) - newaddress(now); } -static int nl_async(struct nlmsghdr *h) +static void nl_async(struct nlmsghdr *h) { if (h->nlmsg_type == NLMSG_ERROR) { struct nlmsgerr *err = NLMSG_DATA(h); if (err->error != 0) my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error))); - return 0; } else if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE) { @@ -371,32 +377,13 @@ static int nl_async(struct nlmsghdr *h) failing. */ struct rtmsg *rtm = NLMSG_DATA(h); - if (rtm->rtm_type == RTN_UNICAST && rtm->rtm_scope == RT_SCOPE_LINK) - { - /* Force re-reading resolv file right now, for luck. */ - daemon->last_resolv = 0; - - if (daemon->srv_save) - { - int fd; - - if (daemon->srv_save->sfd) - fd = daemon->srv_save->sfd->fd; - else if (daemon->rfd_save && daemon->rfd_save->refcount != 0) - fd = daemon->rfd_save->fd; - else - return 0; - - while(sendto(fd, daemon->packet, daemon->packet_len, 0, - &daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send()); - } - } - return 0; + if (rtm->rtm_type == RTN_UNICAST && rtm->rtm_scope == RT_SCOPE_LINK && + (rtm->rtm_table == RT_TABLE_MAIN || + rtm->rtm_table == RT_TABLE_LOCAL)) + queue_event(EVENT_NEWROUTE); } else if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR) - return 1; /* clever bind mode - rescan */ - - return 0; + queue_event(EVENT_NEWADDR); } #endif