Mbufs leak when manually removing incomplete NDP records with pending packet via ndp -d. It happens because lltable_drop_entry_queue() rely on `la_numheld` counter when dropping NDP entries (lles). It turned out NDP code never increased `la_numheld`, so the actual free never happened. Fix the issue by introducing unified lltable_append_entry_queue(), common for both ARP and NDP code, properly addressing packet queue maintenance. Reviewed By: melifaro Differential Revision: https://reviews.freebsd.org/D35365 MFC after: 2 weeks
1524 lines
41 KiB
C
1524 lines
41 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)if_ether.c 8.1 (Berkeley) 6/10/93
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*/
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/*
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* Ethernet address resolution protocol.
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* TODO:
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* add "inuse/lock" bit (or ref. count) along with valid bit
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_inet.h"
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#include <sys/param.h>
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#include <sys/eventhandler.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/queue.h>
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#include <sys/sysctl.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/socket.h>
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#include <sys/syslog.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/if_dl.h>
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#include <net/if_types.h>
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#include <net/netisr.h>
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#include <net/ethernet.h>
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#include <net/route.h>
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#include <net/route/nhop.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/in_fib.h>
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#include <netinet/in_var.h>
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#include <net/if_llatbl.h>
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#include <netinet/if_ether.h>
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#ifdef INET
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#include <netinet/ip_carp.h>
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#endif
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#include <security/mac/mac_framework.h>
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#define SIN(s) ((const struct sockaddr_in *)(s))
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static struct timeval arp_lastlog;
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static int arp_curpps;
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static int arp_maxpps = 1;
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/* Simple ARP state machine */
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enum arp_llinfo_state {
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ARP_LLINFO_INCOMPLETE = 0, /* No LLE data */
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ARP_LLINFO_REACHABLE, /* LLE is valid */
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ARP_LLINFO_VERIFY, /* LLE is valid, need refresh */
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ARP_LLINFO_DELETED, /* LLE is deleted */
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};
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SYSCTL_DECL(_net_link_ether);
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static SYSCTL_NODE(_net_link_ether, PF_INET, inet,
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CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"");
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static SYSCTL_NODE(_net_link_ether, PF_ARP, arp,
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CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"");
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/* timer values */
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VNET_DEFINE_STATIC(int, arpt_keep) = (20*60); /* once resolved, good for 20
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* minutes */
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VNET_DEFINE_STATIC(int, arp_maxtries) = 5;
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VNET_DEFINE_STATIC(int, arp_proxyall) = 0;
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VNET_DEFINE_STATIC(int, arpt_down) = 20; /* keep incomplete entries for
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* 20 seconds */
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VNET_DEFINE_STATIC(int, arpt_rexmit) = 1; /* retransmit arp entries, sec*/
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VNET_PCPUSTAT_DEFINE(struct arpstat, arpstat); /* ARP statistics, see if_arp.h */
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VNET_PCPUSTAT_SYSINIT(arpstat);
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#ifdef VIMAGE
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VNET_PCPUSTAT_SYSUNINIT(arpstat);
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#endif /* VIMAGE */
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VNET_DEFINE_STATIC(int, arp_maxhold) = 16;
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#define V_arpt_keep VNET(arpt_keep)
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#define V_arpt_down VNET(arpt_down)
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#define V_arpt_rexmit VNET(arpt_rexmit)
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#define V_arp_maxtries VNET(arp_maxtries)
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#define V_arp_proxyall VNET(arp_proxyall)
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#define V_arp_maxhold VNET(arp_maxhold)
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arpt_keep), 0,
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"ARP entry lifetime in seconds");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_maxtries), 0,
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"ARP resolution attempts before returning error");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_proxyall), 0,
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"Enable proxy ARP for all suitable requests");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, wait, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arpt_down), 0,
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"Incomplete ARP entry lifetime in seconds");
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SYSCTL_VNET_PCPUSTAT(_net_link_ether_arp, OID_AUTO, stats, struct arpstat,
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arpstat, "ARP statistics (struct arpstat, net/if_arp.h)");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxhold, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_maxhold), 0,
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"Number of packets to hold per ARP entry");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_log_per_second,
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CTLFLAG_RW, &arp_maxpps, 0,
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"Maximum number of remotely triggered ARP messages that can be "
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"logged per second");
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/*
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* Due to the exponential backoff algorithm used for the interval between GARP
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* retransmissions, the maximum number of retransmissions is limited for
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* sanity. This limit corresponds to a maximum interval between retransmissions
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* of 2^16 seconds ~= 18 hours.
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*
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* Making this limit more dynamic is more complicated than worthwhile,
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* especially since sending out GARPs spaced days apart would be of little
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* use. A maximum dynamic limit would look something like:
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*
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* const int max = fls(INT_MAX / hz) - 1;
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*/
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#define MAX_GARP_RETRANSMITS 16
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static int sysctl_garp_rexmit(SYSCTL_HANDLER_ARGS);
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static int garp_rexmit_count = 0; /* GARP retransmission setting. */
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SYSCTL_PROC(_net_link_ether_inet, OID_AUTO, garp_rexmit_count,
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CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_MPSAFE,
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&garp_rexmit_count, 0, sysctl_garp_rexmit, "I",
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"Number of times to retransmit GARP packets;"
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" 0 to disable, maximum of 16");
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VNET_DEFINE_STATIC(int, arp_log_level) = LOG_INFO; /* Min. log(9) level. */
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#define V_arp_log_level VNET(arp_log_level)
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SYSCTL_INT(_net_link_ether_arp, OID_AUTO, log_level, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_log_level), 0,
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"Minimum log(9) level for recording rate limited arp log messages. "
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"The higher will be log more (emerg=0, info=6 (default), debug=7).");
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#define ARP_LOG(pri, ...) do { \
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if ((pri) <= V_arp_log_level && \
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ppsratecheck(&arp_lastlog, &arp_curpps, arp_maxpps)) \
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log((pri), "arp: " __VA_ARGS__); \
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} while (0)
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static void arpintr(struct mbuf *);
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static void arptimer(void *);
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#ifdef INET
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static void in_arpinput(struct mbuf *);
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#endif
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static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr,
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struct ifnet *ifp, int bridged, struct llentry *la);
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static void arp_mark_lle_reachable(struct llentry *la, struct ifnet *ifp);
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static void arp_iflladdr(void *arg __unused, struct ifnet *ifp);
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static eventhandler_tag iflladdr_tag;
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static const struct netisr_handler arp_nh = {
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.nh_name = "arp",
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.nh_handler = arpintr,
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.nh_proto = NETISR_ARP,
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.nh_policy = NETISR_POLICY_SOURCE,
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};
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/*
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* Timeout routine. Age arp_tab entries periodically.
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*/
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static void
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arptimer(void *arg)
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{
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struct llentry *lle = (struct llentry *)arg;
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struct ifnet *ifp;
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if (lle->la_flags & LLE_STATIC) {
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return;
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}
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LLE_WLOCK(lle);
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if (callout_pending(&lle->lle_timer)) {
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/*
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* Here we are a bit odd here in the treatment of
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* active/pending. If the pending bit is set, it got
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* rescheduled before I ran. The active
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* bit we ignore, since if it was stopped
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* in ll_tablefree() and was currently running
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* it would have return 0 so the code would
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* not have deleted it since the callout could
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* not be stopped so we want to go through
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* with the delete here now. If the callout
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* was restarted, the pending bit will be back on and
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* we just want to bail since the callout_reset would
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* return 1 and our reference would have been removed
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* by arpresolve() below.
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*/
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LLE_WUNLOCK(lle);
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return;
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}
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ifp = lle->lle_tbl->llt_ifp;
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CURVNET_SET(ifp->if_vnet);
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switch (lle->ln_state) {
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case ARP_LLINFO_REACHABLE:
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/*
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* Expiration time is approaching.
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* Request usage feedback from the datapath.
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* Change state and re-schedule ourselves.
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*/
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llentry_request_feedback(lle);
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lle->ln_state = ARP_LLINFO_VERIFY;
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callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);
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LLE_WUNLOCK(lle);
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CURVNET_RESTORE();
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return;
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case ARP_LLINFO_VERIFY:
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if (llentry_get_hittime(lle) > 0 && lle->la_preempt > 0) {
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/* Entry was used, issue refresh request */
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struct epoch_tracker et;
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struct in_addr dst;
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dst = lle->r_l3addr.addr4;
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lle->la_preempt--;
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callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);
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LLE_WUNLOCK(lle);
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NET_EPOCH_ENTER(et);
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arprequest(ifp, NULL, &dst, NULL);
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NET_EPOCH_EXIT(et);
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CURVNET_RESTORE();
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return;
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}
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/* Nothing happened. Reschedule if not too late */
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if (lle->la_expire > time_uptime) {
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callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);
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LLE_WUNLOCK(lle);
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CURVNET_RESTORE();
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return;
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}
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break;
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case ARP_LLINFO_INCOMPLETE:
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case ARP_LLINFO_DELETED:
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break;
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}
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if ((lle->la_flags & LLE_DELETED) == 0) {
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int evt;
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if (lle->la_flags & LLE_VALID)
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evt = LLENTRY_EXPIRED;
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else
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evt = LLENTRY_TIMEDOUT;
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EVENTHANDLER_INVOKE(lle_event, lle, evt);
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}
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callout_stop(&lle->lle_timer);
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/* XXX: LOR avoidance. We still have ref on lle. */
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LLE_WUNLOCK(lle);
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IF_AFDATA_LOCK(ifp);
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LLE_WLOCK(lle);
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/* Guard against race with other llentry_free(). */
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if (lle->la_flags & LLE_LINKED) {
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LLE_REMREF(lle);
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lltable_unlink_entry(lle->lle_tbl, lle);
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}
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IF_AFDATA_UNLOCK(ifp);
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size_t pkts_dropped = llentry_free(lle);
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ARPSTAT_ADD(dropped, pkts_dropped);
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ARPSTAT_INC(timeouts);
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CURVNET_RESTORE();
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}
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/*
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* Stores link-layer header for @ifp in format suitable for if_output()
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* into buffer @buf. Resulting header length is stored in @bufsize.
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*
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* Returns 0 on success.
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*/
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static int
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arp_fillheader(struct ifnet *ifp, struct arphdr *ah, int bcast, u_char *buf,
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size_t *bufsize)
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{
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struct if_encap_req ereq;
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int error;
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bzero(buf, *bufsize);
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bzero(&ereq, sizeof(ereq));
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ereq.buf = buf;
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ereq.bufsize = *bufsize;
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ereq.rtype = IFENCAP_LL;
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ereq.family = AF_ARP;
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ereq.lladdr = ar_tha(ah);
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ereq.hdata = (u_char *)ah;
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if (bcast)
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ereq.flags = IFENCAP_FLAG_BROADCAST;
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error = ifp->if_requestencap(ifp, &ereq);
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if (error == 0)
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*bufsize = ereq.bufsize;
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return (error);
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}
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|
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/*
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* Broadcast an ARP request. Caller specifies:
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* - arp header source ip address
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* - arp header target ip address
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* - arp header source ethernet address
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*/
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static int
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arprequest_internal(struct ifnet *ifp, const struct in_addr *sip,
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const struct in_addr *tip, u_char *enaddr)
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{
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struct mbuf *m;
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struct arphdr *ah;
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struct sockaddr sa;
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u_char *carpaddr = NULL;
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uint8_t linkhdr[LLE_MAX_LINKHDR];
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size_t linkhdrsize;
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struct route ro;
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int error;
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NET_EPOCH_ASSERT();
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|
|
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if (sip == NULL) {
|
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/*
|
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* The caller did not supply a source address, try to find
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* a compatible one among those assigned to this interface.
|
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*/
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struct ifaddr *ifa;
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|
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CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
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if (ifa->ifa_addr->sa_family != AF_INET)
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continue;
|
|
|
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if (ifa->ifa_carp) {
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if ((*carp_iamatch_p)(ifa, &carpaddr) == 0)
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continue;
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sip = &IA_SIN(ifa)->sin_addr;
|
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} else {
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carpaddr = NULL;
|
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sip = &IA_SIN(ifa)->sin_addr;
|
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}
|
|
|
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if (0 == ((sip->s_addr ^ tip->s_addr) &
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IA_MASKSIN(ifa)->sin_addr.s_addr))
|
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break; /* found it. */
|
|
}
|
|
if (sip == NULL) {
|
|
printf("%s: cannot find matching address\n", __func__);
|
|
return (EADDRNOTAVAIL);
|
|
}
|
|
}
|
|
if (enaddr == NULL)
|
|
enaddr = carpaddr ? carpaddr : (u_char *)IF_LLADDR(ifp);
|
|
|
|
if ((m = m_gethdr(M_NOWAIT, MT_DATA)) == NULL)
|
|
return (ENOMEM);
|
|
m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
|
|
2 * ifp->if_addrlen;
|
|
m->m_pkthdr.len = m->m_len;
|
|
M_ALIGN(m, m->m_len);
|
|
ah = mtod(m, struct arphdr *);
|
|
bzero((caddr_t)ah, m->m_len);
|
|
#ifdef MAC
|
|
mac_netinet_arp_send(ifp, m);
|
|
#endif
|
|
ah->ar_pro = htons(ETHERTYPE_IP);
|
|
ah->ar_hln = ifp->if_addrlen; /* hardware address length */
|
|
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
|
|
ah->ar_op = htons(ARPOP_REQUEST);
|
|
bcopy(enaddr, ar_sha(ah), ah->ar_hln);
|
|
bcopy(sip, ar_spa(ah), ah->ar_pln);
|
|
bcopy(tip, ar_tpa(ah), ah->ar_pln);
|
|
sa.sa_family = AF_ARP;
|
|
sa.sa_len = 2;
|
|
|
|
/* Calculate link header for sending frame */
|
|
bzero(&ro, sizeof(ro));
|
|
linkhdrsize = sizeof(linkhdr);
|
|
error = arp_fillheader(ifp, ah, 1, linkhdr, &linkhdrsize);
|
|
if (error != 0 && error != EAFNOSUPPORT) {
|
|
m_freem(m);
|
|
ARP_LOG(LOG_ERR, "Failed to calculate ARP header on %s: %d\n",
|
|
if_name(ifp), error);
|
|
return (error);
|
|
}
|
|
|
|
ro.ro_prepend = linkhdr;
|
|
ro.ro_plen = linkhdrsize;
|
|
ro.ro_flags = 0;
|
|
|
|
m->m_flags |= M_BCAST;
|
|
m_clrprotoflags(m); /* Avoid confusing lower layers. */
|
|
error = (*ifp->if_output)(ifp, m, &sa, &ro);
|
|
ARPSTAT_INC(txrequests);
|
|
if (error) {
|
|
ARPSTAT_INC(txerrors);
|
|
ARP_LOG(LOG_DEBUG, "Failed to send ARP packet on %s: %d\n",
|
|
if_name(ifp), error);
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
void
|
|
arprequest(struct ifnet *ifp, const struct in_addr *sip,
|
|
const struct in_addr *tip, u_char *enaddr)
|
|
{
|
|
|
|
(void) arprequest_internal(ifp, sip, tip, enaddr);
|
|
}
|
|
|
|
/*
|
|
* Resolve an IP address into an ethernet address - heavy version.
|
|
* Used internally by arpresolve().
|
|
* We have already checked that we can't use an existing lle without
|
|
* modification so we have to acquire an LLE_EXCLUSIVE lle lock.
|
|
*
|
|
* On success, desten and pflags are filled in and the function returns 0;
|
|
* If the packet must be held pending resolution, we return EWOULDBLOCK
|
|
* On other errors, we return the corresponding error code.
|
|
* Note that m_freem() handles NULL.
|
|
*/
|
|
static int
|
|
arpresolve_full(struct ifnet *ifp, int is_gw, int flags, struct mbuf *m,
|
|
const struct sockaddr *dst, u_char *desten, uint32_t *pflags,
|
|
struct llentry **plle)
|
|
{
|
|
struct llentry *la = NULL, *la_tmp;
|
|
int error, renew;
|
|
char *lladdr;
|
|
int ll_len;
|
|
|
|
NET_EPOCH_ASSERT();
|
|
|
|
if (pflags != NULL)
|
|
*pflags = 0;
|
|
if (plle != NULL)
|
|
*plle = NULL;
|
|
|
|
if ((flags & LLE_CREATE) == 0)
|
|
la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
|
|
if (la == NULL && (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {
|
|
la = lltable_alloc_entry(LLTABLE(ifp), 0, dst);
|
|
if (la == NULL) {
|
|
char addrbuf[INET_ADDRSTRLEN];
|
|
|
|
log(LOG_DEBUG,
|
|
"arpresolve: can't allocate llinfo for %s on %s\n",
|
|
inet_ntoa_r(SIN(dst)->sin_addr, addrbuf),
|
|
if_name(ifp));
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
IF_AFDATA_WLOCK(ifp);
|
|
LLE_WLOCK(la);
|
|
la_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
|
|
/* Prefer ANY existing lle over newly-created one */
|
|
if (la_tmp == NULL)
|
|
lltable_link_entry(LLTABLE(ifp), la);
|
|
IF_AFDATA_WUNLOCK(ifp);
|
|
if (la_tmp != NULL) {
|
|
lltable_free_entry(LLTABLE(ifp), la);
|
|
la = la_tmp;
|
|
}
|
|
}
|
|
if (la == NULL) {
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
if ((la->la_flags & LLE_VALID) &&
|
|
((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {
|
|
if (flags & LLE_ADDRONLY) {
|
|
lladdr = la->ll_addr;
|
|
ll_len = ifp->if_addrlen;
|
|
} else {
|
|
lladdr = la->r_linkdata;
|
|
ll_len = la->r_hdrlen;
|
|
}
|
|
bcopy(lladdr, desten, ll_len);
|
|
|
|
/* Notify LLE code that the entry was used by datapath */
|
|
llentry_provide_feedback(la);
|
|
if (pflags != NULL)
|
|
*pflags = la->la_flags & (LLE_VALID|LLE_IFADDR);
|
|
if (plle) {
|
|
LLE_ADDREF(la);
|
|
*plle = la;
|
|
}
|
|
LLE_WUNLOCK(la);
|
|
return (0);
|
|
}
|
|
|
|
renew = (la->la_asked == 0 || la->la_expire != time_uptime);
|
|
|
|
/*
|
|
* There is an arptab entry, but no ethernet address
|
|
* response yet. Add the mbuf to the list, dropping
|
|
* the oldest packet if we have exceeded the system
|
|
* setting.
|
|
*/
|
|
if (m != NULL) {
|
|
size_t dropped = lltable_append_entry_queue(la, m, V_arp_maxhold);
|
|
ARPSTAT_ADD(dropped, dropped);
|
|
}
|
|
|
|
/*
|
|
* Return EWOULDBLOCK if we have tried less than arp_maxtries. It
|
|
* will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
|
|
* if we have already sent arp_maxtries ARP requests. Retransmit the
|
|
* ARP request, but not faster than one request per second.
|
|
*/
|
|
if (la->la_asked < V_arp_maxtries)
|
|
error = EWOULDBLOCK; /* First request. */
|
|
else
|
|
error = is_gw != 0 ? EHOSTUNREACH : EHOSTDOWN;
|
|
|
|
if (renew) {
|
|
int canceled, e;
|
|
|
|
LLE_ADDREF(la);
|
|
la->la_expire = time_uptime;
|
|
canceled = callout_reset(&la->lle_timer, hz * V_arpt_down,
|
|
arptimer, la);
|
|
if (canceled)
|
|
LLE_REMREF(la);
|
|
la->la_asked++;
|
|
LLE_WUNLOCK(la);
|
|
e = arprequest_internal(ifp, NULL, &SIN(dst)->sin_addr, NULL);
|
|
/*
|
|
* Only overwrite 'error' in case of error; in case of success
|
|
* the proper return value was already set above.
|
|
*/
|
|
if (e != 0)
|
|
return (e);
|
|
return (error);
|
|
}
|
|
|
|
LLE_WUNLOCK(la);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Lookups link header based on an IP address.
|
|
* On input:
|
|
* ifp is the interface we use
|
|
* is_gw != 0 if @dst represents gateway to some destination
|
|
* m is the mbuf. May be NULL if we don't have a packet.
|
|
* dst is the next hop,
|
|
* desten is the storage to put LL header.
|
|
* flags returns subset of lle flags: LLE_VALID | LLE_IFADDR
|
|
*
|
|
* On success, full/partial link header and flags are filled in and
|
|
* the function returns 0.
|
|
* If the packet must be held pending resolution, we return EWOULDBLOCK
|
|
* On other errors, we return the corresponding error code.
|
|
* Note that m_freem() handles NULL.
|
|
*/
|
|
int
|
|
arpresolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
|
|
const struct sockaddr *dst, u_char *desten, uint32_t *pflags,
|
|
struct llentry **plle)
|
|
{
|
|
struct llentry *la = NULL;
|
|
|
|
NET_EPOCH_ASSERT();
|
|
|
|
if (pflags != NULL)
|
|
*pflags = 0;
|
|
if (plle != NULL)
|
|
*plle = NULL;
|
|
|
|
if (m != NULL) {
|
|
if (m->m_flags & M_BCAST) {
|
|
/* broadcast */
|
|
(void)memcpy(desten,
|
|
ifp->if_broadcastaddr, ifp->if_addrlen);
|
|
return (0);
|
|
}
|
|
if (m->m_flags & M_MCAST) {
|
|
/* multicast */
|
|
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
la = lla_lookup(LLTABLE(ifp), plle ? LLE_EXCLUSIVE : LLE_UNLOCKED, dst);
|
|
if (la != NULL && (la->r_flags & RLLE_VALID) != 0) {
|
|
/* Entry found, let's copy lle info */
|
|
bcopy(la->r_linkdata, desten, la->r_hdrlen);
|
|
if (pflags != NULL)
|
|
*pflags = LLE_VALID | (la->r_flags & RLLE_IFADDR);
|
|
/* Notify the LLE handling code that the entry was used. */
|
|
llentry_provide_feedback(la);
|
|
if (plle) {
|
|
LLE_ADDREF(la);
|
|
*plle = la;
|
|
LLE_WUNLOCK(la);
|
|
}
|
|
return (0);
|
|
}
|
|
if (plle && la)
|
|
LLE_WUNLOCK(la);
|
|
|
|
return (arpresolve_full(ifp, is_gw, la == NULL ? LLE_CREATE : 0, m, dst,
|
|
desten, pflags, plle));
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
static void
|
|
arpintr(struct mbuf *m)
|
|
{
|
|
struct arphdr *ar;
|
|
struct ifnet *ifp;
|
|
char *layer;
|
|
int hlen;
|
|
|
|
ifp = m->m_pkthdr.rcvif;
|
|
|
|
if (m->m_len < sizeof(struct arphdr) &&
|
|
((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
|
|
ARP_LOG(LOG_NOTICE, "packet with short header received on %s\n",
|
|
if_name(ifp));
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
|
|
/* Check if length is sufficient */
|
|
if (m->m_len < arphdr_len(ar)) {
|
|
m = m_pullup(m, arphdr_len(ar));
|
|
if (m == NULL) {
|
|
ARP_LOG(LOG_NOTICE, "short packet received on %s\n",
|
|
if_name(ifp));
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
}
|
|
|
|
hlen = 0;
|
|
layer = "";
|
|
switch (ntohs(ar->ar_hrd)) {
|
|
case ARPHRD_ETHER:
|
|
hlen = ETHER_ADDR_LEN; /* RFC 826 */
|
|
layer = "ethernet";
|
|
break;
|
|
case ARPHRD_INFINIBAND:
|
|
hlen = 20; /* RFC 4391, INFINIBAND_ALEN */
|
|
layer = "infiniband";
|
|
break;
|
|
case ARPHRD_IEEE1394:
|
|
hlen = 0; /* SHALL be 16 */ /* RFC 2734 */
|
|
layer = "firewire";
|
|
|
|
/*
|
|
* Restrict too long hardware addresses.
|
|
* Currently we are capable of handling 20-byte
|
|
* addresses ( sizeof(lle->ll_addr) )
|
|
*/
|
|
if (ar->ar_hln >= 20)
|
|
hlen = 16;
|
|
break;
|
|
default:
|
|
ARP_LOG(LOG_NOTICE,
|
|
"packet with unknown hardware format 0x%02d received on "
|
|
"%s\n", ntohs(ar->ar_hrd), if_name(ifp));
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
if (hlen != 0 && hlen != ar->ar_hln) {
|
|
ARP_LOG(LOG_NOTICE,
|
|
"packet with invalid %s address length %d received on %s\n",
|
|
layer, ar->ar_hln, if_name(ifp));
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
ARPSTAT_INC(received);
|
|
switch (ntohs(ar->ar_pro)) {
|
|
#ifdef INET
|
|
case ETHERTYPE_IP:
|
|
in_arpinput(m);
|
|
return;
|
|
#endif
|
|
}
|
|
m_freem(m);
|
|
}
|
|
|
|
#ifdef INET
|
|
/*
|
|
* ARP for Internet protocols on 10 Mb/s Ethernet.
|
|
* Algorithm is that given in RFC 826.
|
|
* In addition, a sanity check is performed on the sender
|
|
* protocol address, to catch impersonators.
|
|
* We no longer handle negotiations for use of trailer protocol:
|
|
* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
|
|
* along with IP replies if we wanted trailers sent to us,
|
|
* and also sent them in response to IP replies.
|
|
* This allowed either end to announce the desire to receive
|
|
* trailer packets.
|
|
* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
|
|
* but formerly didn't normally send requests.
|
|
*/
|
|
static int log_arp_wrong_iface = 1;
|
|
static int log_arp_movements = 1;
|
|
static int log_arp_permanent_modify = 1;
|
|
static int allow_multicast = 0;
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
|
|
&log_arp_wrong_iface, 0,
|
|
"log arp packets arriving on the wrong interface");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
|
|
&log_arp_movements, 0,
|
|
"log arp replies from MACs different than the one in the cache");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
|
|
&log_arp_permanent_modify, 0,
|
|
"log arp replies from MACs different than the one in the permanent arp entry");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, allow_multicast, CTLFLAG_RW,
|
|
&allow_multicast, 0, "accept multicast addresses");
|
|
|
|
static void
|
|
in_arpinput(struct mbuf *m)
|
|
{
|
|
struct arphdr *ah;
|
|
struct ifnet *ifp = m->m_pkthdr.rcvif;
|
|
struct llentry *la = NULL, *la_tmp;
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct sockaddr sa;
|
|
struct in_addr isaddr, itaddr, myaddr;
|
|
u_int8_t *enaddr = NULL;
|
|
int op;
|
|
int bridged = 0, is_bridge = 0;
|
|
int carped;
|
|
struct sockaddr_in sin;
|
|
struct sockaddr *dst;
|
|
struct nhop_object *nh;
|
|
uint8_t linkhdr[LLE_MAX_LINKHDR];
|
|
struct route ro;
|
|
size_t linkhdrsize;
|
|
int lladdr_off;
|
|
int error;
|
|
char addrbuf[INET_ADDRSTRLEN];
|
|
|
|
NET_EPOCH_ASSERT();
|
|
|
|
sin.sin_len = sizeof(struct sockaddr_in);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = 0;
|
|
|
|
if (ifp->if_bridge)
|
|
bridged = 1;
|
|
if (ifp->if_type == IFT_BRIDGE)
|
|
is_bridge = 1;
|
|
|
|
/*
|
|
* We already have checked that mbuf contains enough contiguous data
|
|
* to hold entire arp message according to the arp header.
|
|
*/
|
|
ah = mtod(m, struct arphdr *);
|
|
|
|
/*
|
|
* ARP is only for IPv4 so we can reject packets with
|
|
* a protocol length not equal to an IPv4 address.
|
|
*/
|
|
if (ah->ar_pln != sizeof(struct in_addr)) {
|
|
ARP_LOG(LOG_NOTICE, "requested protocol length != %zu\n",
|
|
sizeof(struct in_addr));
|
|
goto drop;
|
|
}
|
|
|
|
if (allow_multicast == 0 && ETHER_IS_MULTICAST(ar_sha(ah))) {
|
|
ARP_LOG(LOG_NOTICE, "%*D is multicast\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":");
|
|
goto drop;
|
|
}
|
|
|
|
op = ntohs(ah->ar_op);
|
|
(void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
|
|
(void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
|
|
|
|
if (op == ARPOP_REPLY)
|
|
ARPSTAT_INC(rxreplies);
|
|
|
|
/*
|
|
* For a bridge, we want to check the address irrespective
|
|
* of the receive interface. (This will change slightly
|
|
* when we have clusters of interfaces).
|
|
*/
|
|
CK_LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
|
|
if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
|
|
ia->ia_ifp == ifp) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr &&
|
|
(ia->ia_ifa.ifa_carp == NULL ||
|
|
(*carp_iamatch_p)(&ia->ia_ifa, &enaddr))) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
goto match;
|
|
}
|
|
}
|
|
CK_LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
|
|
if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
|
|
ia->ia_ifp == ifp) &&
|
|
isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
goto match;
|
|
}
|
|
|
|
#define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
|
|
(ia->ia_ifp->if_bridge == ifp->if_softc && \
|
|
!bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \
|
|
addr == ia->ia_addr.sin_addr.s_addr)
|
|
/*
|
|
* Check the case when bridge shares its MAC address with
|
|
* some of its children, so packets are claimed by bridge
|
|
* itself (bridge_input() does it first), but they are really
|
|
* meant to be destined to the bridge member.
|
|
*/
|
|
if (is_bridge) {
|
|
CK_LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
|
|
if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
ifp = ia->ia_ifp;
|
|
goto match;
|
|
}
|
|
}
|
|
}
|
|
#undef BDG_MEMBER_MATCHES_ARP
|
|
|
|
/*
|
|
* No match, use the first inet address on the receive interface
|
|
* as a dummy address for the rest of the function.
|
|
*/
|
|
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
|
|
if (ifa->ifa_addr->sa_family == AF_INET &&
|
|
(ifa->ifa_carp == NULL ||
|
|
(*carp_iamatch_p)(ifa, &enaddr))) {
|
|
ia = ifatoia(ifa);
|
|
ifa_ref(ifa);
|
|
goto match;
|
|
}
|
|
|
|
/*
|
|
* If bridging, fall back to using any inet address.
|
|
*/
|
|
if (!bridged || (ia = CK_STAILQ_FIRST(&V_in_ifaddrhead)) == NULL)
|
|
goto drop;
|
|
ifa_ref(&ia->ia_ifa);
|
|
match:
|
|
if (!enaddr)
|
|
enaddr = (u_int8_t *)IF_LLADDR(ifp);
|
|
carped = (ia->ia_ifa.ifa_carp != NULL);
|
|
myaddr = ia->ia_addr.sin_addr;
|
|
ifa_free(&ia->ia_ifa);
|
|
if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
|
|
goto drop; /* it's from me, ignore it. */
|
|
if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
|
|
ARP_LOG(LOG_NOTICE, "link address is broadcast for IP address "
|
|
"%s!\n", inet_ntoa_r(isaddr, addrbuf));
|
|
goto drop;
|
|
}
|
|
|
|
if (ifp->if_addrlen != ah->ar_hln) {
|
|
ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
|
|
"i/f %d (ignored)\n", ifp->if_addrlen,
|
|
(u_char *) ar_sha(ah), ":", ah->ar_hln,
|
|
ifp->if_addrlen);
|
|
goto drop;
|
|
}
|
|
|
|
/*
|
|
* Warn if another host is using the same IP address, but only if the
|
|
* IP address isn't 0.0.0.0, which is used for DHCP only, in which
|
|
* case we suppress the warning to avoid false positive complaints of
|
|
* potential misconfiguration.
|
|
*/
|
|
if (!bridged && !carped && isaddr.s_addr == myaddr.s_addr &&
|
|
myaddr.s_addr != 0) {
|
|
ARP_LOG(LOG_ERR, "%*D is using my IP address %s on %s!\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa_r(isaddr, addrbuf), ifp->if_xname);
|
|
itaddr = myaddr;
|
|
ARPSTAT_INC(dupips);
|
|
goto reply;
|
|
}
|
|
if (ifp->if_flags & IFF_STATICARP)
|
|
goto reply;
|
|
|
|
bzero(&sin, sizeof(sin));
|
|
sin.sin_len = sizeof(struct sockaddr_in);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr = isaddr;
|
|
dst = (struct sockaddr *)&sin;
|
|
la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
|
|
if (la != NULL)
|
|
arp_check_update_lle(ah, isaddr, ifp, bridged, la);
|
|
else if (itaddr.s_addr == myaddr.s_addr) {
|
|
/*
|
|
* Request/reply to our address, but no lle exists yet.
|
|
* Calculate full link prepend to use in lle.
|
|
*/
|
|
linkhdrsize = sizeof(linkhdr);
|
|
if (lltable_calc_llheader(ifp, AF_INET, ar_sha(ah), linkhdr,
|
|
&linkhdrsize, &lladdr_off) != 0)
|
|
goto reply;
|
|
|
|
/* Allocate new entry */
|
|
la = lltable_alloc_entry(LLTABLE(ifp), 0, dst);
|
|
if (la == NULL) {
|
|
/*
|
|
* lle creation may fail if source address belongs
|
|
* to non-directly connected subnet. However, we
|
|
* will try to answer the request instead of dropping
|
|
* frame.
|
|
*/
|
|
goto reply;
|
|
}
|
|
lltable_set_entry_addr(ifp, la, linkhdr, linkhdrsize,
|
|
lladdr_off);
|
|
|
|
IF_AFDATA_WLOCK(ifp);
|
|
LLE_WLOCK(la);
|
|
la_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
|
|
|
|
/*
|
|
* Check if lle still does not exists.
|
|
* If it does, that means that we either
|
|
* 1) have configured it explicitly, via
|
|
* 1a) 'arp -s' static entry or
|
|
* 1b) interface address static record
|
|
* or
|
|
* 2) it was the result of sending first packet to-host
|
|
* or
|
|
* 3) it was another arp reply packet we handled in
|
|
* different thread.
|
|
*
|
|
* In all cases except 3) we definitely need to prefer
|
|
* existing lle. For the sake of simplicity, prefer any
|
|
* existing lle over newly-create one.
|
|
*/
|
|
if (la_tmp == NULL)
|
|
lltable_link_entry(LLTABLE(ifp), la);
|
|
IF_AFDATA_WUNLOCK(ifp);
|
|
|
|
if (la_tmp == NULL) {
|
|
arp_mark_lle_reachable(la, ifp);
|
|
LLE_WUNLOCK(la);
|
|
} else {
|
|
/* Free newly-create entry and handle packet */
|
|
lltable_free_entry(LLTABLE(ifp), la);
|
|
la = la_tmp;
|
|
la_tmp = NULL;
|
|
arp_check_update_lle(ah, isaddr, ifp, bridged, la);
|
|
/* arp_check_update_lle() returns @la unlocked */
|
|
}
|
|
la = NULL;
|
|
}
|
|
reply:
|
|
if (op != ARPOP_REQUEST)
|
|
goto drop;
|
|
ARPSTAT_INC(rxrequests);
|
|
|
|
if (itaddr.s_addr == myaddr.s_addr) {
|
|
/* Shortcut.. the receiving interface is the target. */
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
|
} else {
|
|
/*
|
|
* Destination address is not ours. Check if
|
|
* proxyarp entry exists or proxyarp is turned on globally.
|
|
*/
|
|
struct llentry *lle;
|
|
|
|
sin.sin_addr = itaddr;
|
|
lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
|
|
|
|
if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), lle->ll_addr, ah->ar_hln);
|
|
LLE_RUNLOCK(lle);
|
|
} else {
|
|
if (lle != NULL)
|
|
LLE_RUNLOCK(lle);
|
|
|
|
if (!V_arp_proxyall)
|
|
goto drop;
|
|
|
|
NET_EPOCH_ASSERT();
|
|
nh = fib4_lookup(ifp->if_fib, itaddr, 0, 0, 0);
|
|
if (nh == NULL)
|
|
goto drop;
|
|
|
|
/*
|
|
* Don't send proxies for nodes on the same interface
|
|
* as this one came out of, or we'll get into a fight
|
|
* over who claims what Ether address.
|
|
*/
|
|
if (nh->nh_ifp == ifp)
|
|
goto drop;
|
|
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
|
|
|
/*
|
|
* Also check that the node which sent the ARP packet
|
|
* is on the interface we expect it to be on. This
|
|
* avoids ARP chaos if an interface is connected to the
|
|
* wrong network.
|
|
*/
|
|
|
|
nh = fib4_lookup(ifp->if_fib, isaddr, 0, 0, 0);
|
|
if (nh == NULL)
|
|
goto drop;
|
|
if (nh->nh_ifp != ifp) {
|
|
ARP_LOG(LOG_INFO, "proxy: ignoring request"
|
|
" from %s via %s\n",
|
|
inet_ntoa_r(isaddr, addrbuf),
|
|
ifp->if_xname);
|
|
goto drop;
|
|
}
|
|
|
|
#ifdef DEBUG_PROXY
|
|
printf("arp: proxying for %s\n",
|
|
inet_ntoa_r(itaddr, addrbuf));
|
|
#endif
|
|
}
|
|
}
|
|
|
|
if (itaddr.s_addr == myaddr.s_addr &&
|
|
IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
|
|
/* RFC 3927 link-local IPv4; always reply by broadcast. */
|
|
#ifdef DEBUG_LINKLOCAL
|
|
printf("arp: sending reply for link-local addr %s\n",
|
|
inet_ntoa_r(itaddr, addrbuf));
|
|
#endif
|
|
m->m_flags |= M_BCAST;
|
|
m->m_flags &= ~M_MCAST;
|
|
} else {
|
|
/* default behaviour; never reply by broadcast. */
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
|
}
|
|
(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
|
|
(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
|
|
ah->ar_op = htons(ARPOP_REPLY);
|
|
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
|
m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
|
|
m->m_pkthdr.len = m->m_len;
|
|
m->m_pkthdr.rcvif = NULL;
|
|
sa.sa_family = AF_ARP;
|
|
sa.sa_len = 2;
|
|
|
|
/* Calculate link header for sending frame */
|
|
bzero(&ro, sizeof(ro));
|
|
linkhdrsize = sizeof(linkhdr);
|
|
error = arp_fillheader(ifp, ah, 0, linkhdr, &linkhdrsize);
|
|
|
|
/*
|
|
* arp_fillheader() may fail due to lack of support inside encap request
|
|
* routing. This is not necessary an error, AF_ARP can/should be handled
|
|
* by if_output().
|
|
*/
|
|
if (error != 0 && error != EAFNOSUPPORT) {
|
|
ARP_LOG(LOG_ERR, "Failed to calculate ARP header on %s: %d\n",
|
|
if_name(ifp), error);
|
|
goto drop;
|
|
}
|
|
|
|
ro.ro_prepend = linkhdr;
|
|
ro.ro_plen = linkhdrsize;
|
|
ro.ro_flags = 0;
|
|
|
|
m_clrprotoflags(m); /* Avoid confusing lower layers. */
|
|
(*ifp->if_output)(ifp, m, &sa, &ro);
|
|
ARPSTAT_INC(txreplies);
|
|
return;
|
|
|
|
drop:
|
|
m_freem(m);
|
|
}
|
|
#endif
|
|
|
|
static struct mbuf *
|
|
arp_grab_holdchain(struct llentry *la)
|
|
{
|
|
struct mbuf *chain;
|
|
|
|
LLE_WLOCK_ASSERT(la);
|
|
|
|
chain = la->la_hold;
|
|
la->la_hold = NULL;
|
|
la->la_numheld = 0;
|
|
|
|
return (chain);
|
|
}
|
|
|
|
static void
|
|
arp_flush_holdchain(struct ifnet *ifp, struct llentry *la, struct mbuf *chain)
|
|
{
|
|
struct mbuf *m_hold, *m_hold_next;
|
|
struct sockaddr_in sin;
|
|
|
|
NET_EPOCH_ASSERT();
|
|
|
|
struct route ro = {
|
|
.ro_prepend = la->r_linkdata,
|
|
.ro_plen = la->r_hdrlen,
|
|
};
|
|
|
|
lltable_fill_sa_entry(la, (struct sockaddr *)&sin);
|
|
|
|
for (m_hold = chain; m_hold != NULL; m_hold = m_hold_next) {
|
|
m_hold_next = m_hold->m_nextpkt;
|
|
m_hold->m_nextpkt = NULL;
|
|
/* Avoid confusing lower layers. */
|
|
m_clrprotoflags(m_hold);
|
|
(*ifp->if_output)(ifp, m_hold, (struct sockaddr *)&sin, &ro);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Checks received arp data against existing @la.
|
|
* Updates lle state/performs notification if necessary.
|
|
*/
|
|
static void
|
|
arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr, struct ifnet *ifp,
|
|
int bridged, struct llentry *la)
|
|
{
|
|
uint8_t linkhdr[LLE_MAX_LINKHDR];
|
|
size_t linkhdrsize;
|
|
int lladdr_off;
|
|
char addrbuf[INET_ADDRSTRLEN];
|
|
|
|
LLE_WLOCK_ASSERT(la);
|
|
|
|
/* the following is not an error when doing bridging */
|
|
if (!bridged && la->lle_tbl->llt_ifp != ifp) {
|
|
if (log_arp_wrong_iface)
|
|
ARP_LOG(LOG_WARNING, "%s is on %s "
|
|
"but got reply from %*D on %s\n",
|
|
inet_ntoa_r(isaddr, addrbuf),
|
|
la->lle_tbl->llt_ifp->if_xname,
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
LLE_WUNLOCK(la);
|
|
return;
|
|
}
|
|
if ((la->la_flags & LLE_VALID) &&
|
|
bcmp(ar_sha(ah), la->ll_addr, ifp->if_addrlen)) {
|
|
if (la->la_flags & LLE_STATIC) {
|
|
LLE_WUNLOCK(la);
|
|
if (log_arp_permanent_modify)
|
|
ARP_LOG(LOG_ERR,
|
|
"%*D attempts to modify "
|
|
"permanent entry for %s on %s\n",
|
|
ifp->if_addrlen,
|
|
(u_char *)ar_sha(ah), ":",
|
|
inet_ntoa_r(isaddr, addrbuf),
|
|
ifp->if_xname);
|
|
return;
|
|
}
|
|
if (log_arp_movements) {
|
|
ARP_LOG(LOG_INFO, "%s moved from %*D "
|
|
"to %*D on %s\n",
|
|
inet_ntoa_r(isaddr, addrbuf),
|
|
ifp->if_addrlen,
|
|
(u_char *)la->ll_addr, ":",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
}
|
|
}
|
|
|
|
/* Calculate full link prepend to use in lle */
|
|
linkhdrsize = sizeof(linkhdr);
|
|
if (lltable_calc_llheader(ifp, AF_INET, ar_sha(ah), linkhdr,
|
|
&linkhdrsize, &lladdr_off) != 0) {
|
|
LLE_WUNLOCK(la);
|
|
return;
|
|
}
|
|
|
|
/* Check if something has changed */
|
|
if (memcmp(la->r_linkdata, linkhdr, linkhdrsize) != 0 ||
|
|
(la->la_flags & LLE_VALID) == 0) {
|
|
/* Try to perform LLE update */
|
|
if (lltable_try_set_entry_addr(ifp, la, linkhdr, linkhdrsize,
|
|
lladdr_off) == 0) {
|
|
LLE_WUNLOCK(la);
|
|
return;
|
|
}
|
|
|
|
/* Clear fast path feedback request if set */
|
|
llentry_mark_used(la);
|
|
}
|
|
|
|
arp_mark_lle_reachable(la, ifp);
|
|
|
|
/*
|
|
* The packets are all freed within the call to the output
|
|
* routine.
|
|
*
|
|
* NB: The lock MUST be released before the call to the
|
|
* output routine.
|
|
*/
|
|
if (la->la_hold != NULL) {
|
|
struct mbuf *chain;
|
|
|
|
chain = arp_grab_holdchain(la);
|
|
LLE_WUNLOCK(la);
|
|
arp_flush_holdchain(ifp, la, chain);
|
|
} else
|
|
LLE_WUNLOCK(la);
|
|
}
|
|
|
|
static void
|
|
arp_mark_lle_reachable(struct llentry *la, struct ifnet *ifp)
|
|
{
|
|
int canceled, wtime;
|
|
|
|
LLE_WLOCK_ASSERT(la);
|
|
|
|
la->ln_state = ARP_LLINFO_REACHABLE;
|
|
EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
|
|
|
|
if ((ifp->if_flags & IFF_STICKYARP) != 0)
|
|
la->la_flags |= LLE_STATIC;
|
|
|
|
if (!(la->la_flags & LLE_STATIC)) {
|
|
LLE_ADDREF(la);
|
|
la->la_expire = time_uptime + V_arpt_keep;
|
|
wtime = V_arpt_keep - V_arp_maxtries * V_arpt_rexmit;
|
|
if (wtime < 0)
|
|
wtime = V_arpt_keep;
|
|
canceled = callout_reset(&la->lle_timer,
|
|
hz * wtime, arptimer, la);
|
|
if (canceled)
|
|
LLE_REMREF(la);
|
|
}
|
|
la->la_asked = 0;
|
|
la->la_preempt = V_arp_maxtries;
|
|
}
|
|
|
|
/*
|
|
* Add permanent link-layer record for given interface address.
|
|
*/
|
|
static __noinline void
|
|
arp_add_ifa_lle(struct ifnet *ifp, const struct sockaddr *dst)
|
|
{
|
|
struct llentry *lle, *lle_tmp;
|
|
|
|
/*
|
|
* Interface address LLE record is considered static
|
|
* because kernel code relies on LLE_STATIC flag to check
|
|
* if these entries can be rewriten by arp updates.
|
|
*/
|
|
lle = lltable_alloc_entry(LLTABLE(ifp), LLE_IFADDR | LLE_STATIC, dst);
|
|
if (lle == NULL) {
|
|
log(LOG_INFO, "arp_ifinit: cannot create arp "
|
|
"entry for interface address\n");
|
|
return;
|
|
}
|
|
|
|
IF_AFDATA_WLOCK(ifp);
|
|
LLE_WLOCK(lle);
|
|
/* Unlink any entry if exists */
|
|
lle_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
|
|
if (lle_tmp != NULL)
|
|
lltable_unlink_entry(LLTABLE(ifp), lle_tmp);
|
|
|
|
lltable_link_entry(LLTABLE(ifp), lle);
|
|
IF_AFDATA_WUNLOCK(ifp);
|
|
|
|
if (lle_tmp != NULL)
|
|
EVENTHANDLER_INVOKE(lle_event, lle_tmp, LLENTRY_EXPIRED);
|
|
|
|
EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_RESOLVED);
|
|
LLE_WUNLOCK(lle);
|
|
if (lle_tmp != NULL)
|
|
lltable_free_entry(LLTABLE(ifp), lle_tmp);
|
|
}
|
|
|
|
/*
|
|
* Handle the garp_rexmit_count. Like sysctl_handle_int(), but limits the range
|
|
* of valid values.
|
|
*/
|
|
static int
|
|
sysctl_garp_rexmit(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
int rexmit_count = *(int *)arg1;
|
|
|
|
error = sysctl_handle_int(oidp, &rexmit_count, 0, req);
|
|
|
|
/* Enforce limits on any new value that may have been set. */
|
|
if (!error && req->newptr) {
|
|
/* A new value was set. */
|
|
if (rexmit_count < 0) {
|
|
rexmit_count = 0;
|
|
} else if (rexmit_count > MAX_GARP_RETRANSMITS) {
|
|
rexmit_count = MAX_GARP_RETRANSMITS;
|
|
}
|
|
*(int *)arg1 = rexmit_count;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Retransmit a Gratuitous ARP (GARP) and, if necessary, schedule a callout to
|
|
* retransmit it again. A pending callout owns a reference to the ifa.
|
|
*/
|
|
static void
|
|
garp_rexmit(void *arg)
|
|
{
|
|
struct in_ifaddr *ia = arg;
|
|
|
|
if (callout_pending(&ia->ia_garp_timer) ||
|
|
!callout_active(&ia->ia_garp_timer)) {
|
|
IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);
|
|
ifa_free(&ia->ia_ifa);
|
|
return;
|
|
}
|
|
|
|
CURVNET_SET(ia->ia_ifa.ifa_ifp->if_vnet);
|
|
|
|
/*
|
|
* Drop lock while the ARP request is generated.
|
|
*/
|
|
IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);
|
|
|
|
arprequest(ia->ia_ifa.ifa_ifp, &IA_SIN(ia)->sin_addr,
|
|
&IA_SIN(ia)->sin_addr, IF_LLADDR(ia->ia_ifa.ifa_ifp));
|
|
|
|
/*
|
|
* Increment the count of retransmissions. If the count has reached the
|
|
* maximum value, stop sending the GARP packets. Otherwise, schedule
|
|
* the callout to retransmit another GARP packet.
|
|
*/
|
|
++ia->ia_garp_count;
|
|
if (ia->ia_garp_count >= garp_rexmit_count) {
|
|
ifa_free(&ia->ia_ifa);
|
|
} else {
|
|
int rescheduled;
|
|
IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp);
|
|
rescheduled = callout_reset(&ia->ia_garp_timer,
|
|
(1 << ia->ia_garp_count) * hz,
|
|
garp_rexmit, ia);
|
|
IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);
|
|
if (rescheduled) {
|
|
ifa_free(&ia->ia_ifa);
|
|
}
|
|
}
|
|
|
|
CURVNET_RESTORE();
|
|
}
|
|
|
|
/*
|
|
* Start the GARP retransmit timer.
|
|
*
|
|
* A single GARP is always transmitted when an IPv4 address is added
|
|
* to an interface and that is usually sufficient. However, in some
|
|
* circumstances, such as when a shared address is passed between
|
|
* cluster nodes, this single GARP may occasionally be dropped or
|
|
* lost. This can lead to neighbors on the network link working with a
|
|
* stale ARP cache and sending packets destined for that address to
|
|
* the node that previously owned the address, which may not respond.
|
|
*
|
|
* To avoid this situation, GARP retransmits can be enabled by setting
|
|
* the net.link.ether.inet.garp_rexmit_count sysctl to a value greater
|
|
* than zero. The setting represents the maximum number of
|
|
* retransmissions. The interval between retransmissions is calculated
|
|
* using an exponential backoff algorithm, doubling each time, so the
|
|
* retransmission intervals are: {1, 2, 4, 8, 16, ...} (seconds).
|
|
*/
|
|
static void
|
|
garp_timer_start(struct ifaddr *ifa)
|
|
{
|
|
struct in_ifaddr *ia = (struct in_ifaddr *) ifa;
|
|
|
|
IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp);
|
|
ia->ia_garp_count = 0;
|
|
if (callout_reset(&ia->ia_garp_timer, (1 << ia->ia_garp_count) * hz,
|
|
garp_rexmit, ia) == 0) {
|
|
ifa_ref(ifa);
|
|
}
|
|
IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);
|
|
}
|
|
|
|
void
|
|
arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
|
|
{
|
|
struct epoch_tracker et;
|
|
const struct sockaddr_in *dst_in;
|
|
const struct sockaddr *dst;
|
|
|
|
if (ifa->ifa_carp != NULL)
|
|
return;
|
|
|
|
dst = ifa->ifa_addr;
|
|
dst_in = (const struct sockaddr_in *)dst;
|
|
|
|
if (ntohl(dst_in->sin_addr.s_addr) == INADDR_ANY)
|
|
return;
|
|
NET_EPOCH_ENTER(et);
|
|
arp_announce_ifaddr(ifp, dst_in->sin_addr, IF_LLADDR(ifp));
|
|
NET_EPOCH_EXIT(et);
|
|
if (garp_rexmit_count > 0) {
|
|
garp_timer_start(ifa);
|
|
}
|
|
|
|
arp_add_ifa_lle(ifp, dst);
|
|
}
|
|
|
|
void
|
|
arp_announce_ifaddr(struct ifnet *ifp, struct in_addr addr, u_char *enaddr)
|
|
{
|
|
|
|
if (ntohl(addr.s_addr) != INADDR_ANY)
|
|
arprequest(ifp, &addr, &addr, enaddr);
|
|
}
|
|
|
|
/*
|
|
* Sends gratuitous ARPs for each ifaddr to notify other
|
|
* nodes about the address change.
|
|
*/
|
|
static __noinline void
|
|
arp_handle_ifllchange(struct ifnet *ifp)
|
|
{
|
|
struct ifaddr *ifa;
|
|
|
|
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
|
|
if (ifa->ifa_addr->sa_family == AF_INET)
|
|
arp_ifinit(ifp, ifa);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* A handler for interface link layer address change event.
|
|
*/
|
|
static void
|
|
arp_iflladdr(void *arg __unused, struct ifnet *ifp)
|
|
{
|
|
/* if_bridge can update its lladdr during if_vmove(), after we've done
|
|
* if_detach_internal()/dom_ifdetach(). */
|
|
if (ifp->if_afdata[AF_INET] == NULL)
|
|
return;
|
|
|
|
lltable_update_ifaddr(LLTABLE(ifp));
|
|
|
|
if ((ifp->if_flags & IFF_UP) != 0)
|
|
arp_handle_ifllchange(ifp);
|
|
}
|
|
|
|
static void
|
|
vnet_arp_init(void)
|
|
{
|
|
|
|
if (IS_DEFAULT_VNET(curvnet)) {
|
|
netisr_register(&arp_nh);
|
|
iflladdr_tag = EVENTHANDLER_REGISTER(iflladdr_event,
|
|
arp_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
|
|
}
|
|
#ifdef VIMAGE
|
|
else
|
|
netisr_register_vnet(&arp_nh);
|
|
#endif
|
|
}
|
|
VNET_SYSINIT(vnet_arp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_SECOND,
|
|
vnet_arp_init, 0);
|
|
|
|
#ifdef VIMAGE
|
|
/*
|
|
* We have to unregister ARP along with IP otherwise we risk doing INADDR_HASH
|
|
* lookups after destroying the hash. Ideally this would go on SI_ORDER_3.5.
|
|
*/
|
|
static void
|
|
vnet_arp_destroy(__unused void *arg)
|
|
{
|
|
|
|
netisr_unregister_vnet(&arp_nh);
|
|
}
|
|
VNET_SYSUNINIT(vnet_arp_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
|
|
vnet_arp_destroy, NULL);
|
|
#endif
|