cregit-Linux how code gets into the kernel

Release 4.14 net/ipv4/icmp.c

Directory: net/ipv4
/*
 *      NET3:   Implementation of the ICMP protocol layer.
 *
 *              Alan Cox, <alan@lxorguk.ukuu.org.uk>
 *
 *      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 the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *      Some of the function names and the icmp unreach table for this
 *      module were derived from [icmp.c 1.0.11 06/02/93] by
 *      Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
 *      Other than that this module is a complete rewrite.
 *
 *      Fixes:
 *      Clemens Fruhwirth       :       introduce global icmp rate limiting
 *                                      with icmp type masking ability instead
 *                                      of broken per type icmp timeouts.
 *              Mike Shaver     :       RFC1122 checks.
 *              Alan Cox        :       Multicast ping reply as self.
 *              Alan Cox        :       Fix atomicity lockup in ip_build_xmit
 *                                      call.
 *              Alan Cox        :       Added 216,128 byte paths to the MTU
 *                                      code.
 *              Martin Mares    :       RFC1812 checks.
 *              Martin Mares    :       Can be configured to follow redirects
 *                                      if acting as a router _without_ a
 *                                      routing protocol (RFC 1812).
 *              Martin Mares    :       Echo requests may be configured to
 *                                      be ignored (RFC 1812).
 *              Martin Mares    :       Limitation of ICMP error message
 *                                      transmit rate (RFC 1812).
 *              Martin Mares    :       TOS and Precedence set correctly
 *                                      (RFC 1812).
 *              Martin Mares    :       Now copying as much data from the
 *                                      original packet as we can without
 *                                      exceeding 576 bytes (RFC 1812).
 *      Willy Konynenberg       :       Transparent proxying support.
 *              Keith Owens     :       RFC1191 correction for 4.2BSD based
 *                                      path MTU bug.
 *              Thomas Quinot   :       ICMP Dest Unreach codes up to 15 are
 *                                      valid (RFC 1812).
 *              Andi Kleen      :       Check all packet lengths properly
 *                                      and moved all kfree_skb() up to
 *                                      icmp_rcv.
 *              Andi Kleen      :       Move the rate limit bookkeeping
 *                                      into the dest entry and use a token
 *                                      bucket filter (thanks to ANK). Make
 *                                      the rates sysctl configurable.
 *              Yu Tianli       :       Fixed two ugly bugs in icmp_send
 *                                      - IP option length was accounted wrongly
 *                                      - ICMP header length was not accounted
 *                                        at all.
 *              Tristan Greaves :       Added sysctl option to ignore bogus
 *                                      broadcast responses from broken routers.
 *
 * To Fix:
 *
 *      - Should use skb_pull() instead of all the manual checking.
 *        This would also greatly simply some upper layer error handlers. --AK
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/string.h>
#include <linux/netfilter_ipv4.h>
#include <linux/slab.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/protocol.h>
#include <net/icmp.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/raw.h>
#include <net/ping.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include <net/inet_common.h>
#include <net/ip_fib.h>
#include <net/l3mdev.h>

/*
 *      Build xmit assembly blocks
 */


struct icmp_bxm {
	
struct sk_buff *skb;
	
int offset;
	
int data_len;

	struct {
		
struct icmphdr icmph;
		
__be32	       times[3];
	
} data;
	
int head_len;
	
struct ip_options_data replyopts;
};

/* An array of errno for error messages from dest unreach. */
/* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */


const struct icmp_err icmp_err_convert[] = {
	{
		.errno = ENETUNREACH,	/* ICMP_NET_UNREACH */
		.fatal = 0,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNREACH */
		.fatal = 0,
        },
	{
		.errno = ENOPROTOOPT	/* ICMP_PROT_UNREACH */,
		.fatal = 1,
        },
	{
		.errno = ECONNREFUSED,	/* ICMP_PORT_UNREACH */
		.fatal = 1,
        },
	{
		.errno = EMSGSIZE,	/* ICMP_FRAG_NEEDED */
		.fatal = 0,
        },
	{
		.errno = EOPNOTSUPP,	/* ICMP_SR_FAILED */
		.fatal = 0,
        },
	{
		.errno = ENETUNREACH,	/* ICMP_NET_UNKNOWN */
		.fatal = 1,
        },
	{
		.errno = EHOSTDOWN,	/* ICMP_HOST_UNKNOWN */
		.fatal = 1,
        },
	{
		.errno = ENONET,	/* ICMP_HOST_ISOLATED */
		.fatal = 1,
        },
	{
		.errno = ENETUNREACH,	/* ICMP_NET_ANO */
		.fatal = 1,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_HOST_ANO */
		.fatal = 1,
        },
	{
		.errno = ENETUNREACH,	/* ICMP_NET_UNR_TOS */
		.fatal = 0,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNR_TOS */
		.fatal = 0,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_PKT_FILTERED */
		.fatal = 1,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_PREC_VIOLATION */
		.fatal = 1,
        },
	{
		.errno = EHOSTUNREACH,	/* ICMP_PREC_CUTOFF */
		.fatal = 1,
        },
};

EXPORT_SYMBOL(icmp_err_convert);

/*
 *      ICMP control array. This specifies what to do with each ICMP.
 */


struct icmp_control {
	
bool (*handler)(struct sk_buff *skb);
	
short   error;		/* This ICMP is classed as an error message */
};


static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];

/*
 *      The ICMP socket(s). This is the most convenient way to flow control
 *      our ICMP output as well as maintain a clean interface throughout
 *      all layers. All Socketless IP sends will soon be gone.
 *
 *      On SMP we have one ICMP socket per-cpu.
 */

static struct sock *icmp_sk(struct net *net) { return *this_cpu_ptr(net->ipv4.icmp_sk); }

Contributors

PersonTokensPropCommitsCommitProp
Denis V. Lunev1979.17%360.00%
Eric Dumazet416.67%120.00%
David S. Miller14.17%120.00%
Total24100.00%5100.00%

/* Called with BH disabled */
static inline struct sock *icmp_xmit_lock(struct net *net) { struct sock *sk; sk = icmp_sk(net); if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { /* This can happen if the output path signals a * dst_link_failure() for an outgoing ICMP packet. */ return NULL; } return sk; }

Contributors

PersonTokensPropCommitsCommitProp
Denis V. Lunev2243.14%228.57%
Linus Torvalds (pre-git)1733.33%114.29%
David S. Miller1019.61%228.57%
Eric Dumazet11.96%114.29%
Arnaldo Carvalho de Melo11.96%114.29%
Total51100.00%7100.00%


static inline void icmp_xmit_unlock(struct sock *sk) { spin_unlock(&sk->sk_lock.slock); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1359.09%116.67%
Denis V. Lunev522.73%116.67%
David S. Miller14.55%116.67%
Jesper Dangaard Brouer14.55%116.67%
Arnaldo Carvalho de Melo14.55%116.67%
Eric Dumazet14.55%116.67%
Total22100.00%6100.00%

int sysctl_icmp_msgs_per_sec __read_mostly = 1000; int sysctl_icmp_msgs_burst __read_mostly = 50; static struct { spinlock_t lock; u32 credit; u32 stamp; } icmp_global = { .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), }; /** * icmp_global_allow - Are we allowed to send one more ICMP message ? * * Uses a token bucket to limit our ICMP messages to sysctl_icmp_msgs_per_sec. * Returns false if we reached the limit and can not send another packet. * Note: called with BH disabled */
bool icmp_global_allow(void) { u32 credit, delta, incr = 0, now = (u32)jiffies; bool rc = false; /* Check if token bucket is empty and cannot be refilled * without taking the spinlock. */ if (!icmp_global.credit) { delta = min_t(u32, now - icmp_global.stamp, HZ); if (delta < HZ / 50) return false; } spin_lock(&icmp_global.lock); delta = min_t(u32, now - icmp_global.stamp, HZ); if (delta >= HZ / 50) { incr = sysctl_icmp_msgs_per_sec * delta / HZ ; if (incr) icmp_global.stamp = now; } credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst); if (credit) { credit--; rc = true; } icmp_global.credit = credit; spin_unlock(&icmp_global.lock); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Eric Dumazet160100.00%1100.00%
Total160100.00%1100.00%

EXPORT_SYMBOL(icmp_global_allow);
static bool icmpv4_mask_allow(struct net *net, int type, int code) { if (type > NR_ICMP_TYPES) return true; /* Don't limit PMTU discovery. */ if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) return true; /* Limit if icmp type is enabled in ratemask. */ if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask)) return true; return false; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer64100.00%1100.00%
Total64100.00%1100.00%


static bool icmpv4_global_allow(struct net *net, int type, int code) { if (icmpv4_mask_allow(net, type, code)) return true; if (icmp_global_allow()) return true; return false; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer42100.00%1100.00%
Total42100.00%1100.00%

/* * Send an ICMP frame. */
static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, struct flowi4 *fl4, int type, int code) { struct dst_entry *dst = &rt->dst; struct inet_peer *peer; bool rc = true; int vif; if (icmpv4_mask_allow(net, type, code)) goto out; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) goto out; vif = l3mdev_master_ifindex(dst->dev); peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1); rc = inet_peer_xrlim_allow(peer, net->ipv4.sysctl_icmp_ratelimit); if (peer) inet_putpeer(peer); out: return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5136.69%320.00%
David S. Miller2920.86%320.00%
Jesper Dangaard Brouer1611.51%16.67%
Arnaldo Carvalho de Melo1510.79%16.67%
Pavel Emelyanov96.47%213.33%
David Ahern96.47%213.33%
Neal Cardwell42.88%16.67%
Eric Dumazet32.16%16.67%
Linus Torvalds32.16%16.67%
Total139100.00%15100.00%

/* * Maintain the counters used in the SNMP statistics for outgoing ICMP */
void icmp_out_count(struct net *net, unsigned char type) { ICMPMSGOUT_INC_STATS(net, type); ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1450.00%225.00%
Pavel Emelyanov932.14%337.50%
David L Stevens310.71%112.50%
Hideaki Yoshifuji / 吉藤英明13.57%112.50%
Ravikiran G. Thirumalai13.57%112.50%
Total28100.00%8100.00%

/* * Checksum each fragment, and on the first include the headers and final * checksum. */
static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) { struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; __wsum csum; csum = skb_copy_and_csum_bits(icmp_param->skb, icmp_param->offset + offset, to, len, 0); skb->csum = csum_block_add(skb->csum, csum, odd); if (icmp_pointers[icmp_param->data.icmph.type].error) nf_ct_attach(skb, icmp_param->skb); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4441.51%646.15%
Alexey Kuznetsov2927.36%215.38%
Patrick McHardy2422.64%17.69%
Linus Torvalds65.66%17.69%
Arnaldo Carvalho de Melo10.94%17.69%
Al Viro10.94%17.69%
Adrian Bunk10.94%17.69%
Total106100.00%13100.00%


static void icmp_push_reply(struct icmp_bxm *icmp_param, struct flowi4 *fl4, struct ipcm_cookie *ipc, struct rtable **rt) { struct sock *sk; struct sk_buff *skb; sk = icmp_sk(dev_net((*rt)->dst.dev)); if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param, icmp_param->data_len+icmp_param->head_len, icmp_param->head_len, ipc, rt, MSG_DONTWAIT) < 0) { __ICMP_INC_STATS(sock_net(sk), ICMP_MIB_OUTERRORS); ip_flush_pending_frames(sk); } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { struct icmphdr *icmph = icmp_hdr(skb); __wsum csum = 0; struct sk_buff *skb1; skb_queue_walk(&sk->sk_write_queue, skb1) { csum = csum_add(csum, skb1->csum); } csum = csum_partial_copy_nocheck((void *)&icmp_param->data, (char *)icmph, icmp_param->head_len, csum); icmph->checksum = csum_fold(csum); skb->ip_summed = CHECKSUM_NONE; ip_push_pending_frames(sk, fl4); } }

Contributors

PersonTokensPropCommitsCommitProp
Alexey Kuznetsov11353.81%14.35%
Linus Torvalds (pre-git)3215.24%834.78%
Denis V. Lunev178.10%313.04%
Eric Dumazet167.62%313.04%
Patrick McHardy104.76%14.35%
David S. Miller94.29%28.70%
Linus Torvalds52.38%14.35%
Arnaldo Carvalho de Melo41.90%28.70%
Hideaki Yoshifuji / 吉藤英明31.43%14.35%
Al Viro10.48%14.35%
Total210100.00%23100.00%

/* * Driving logic for building and sending ICMP messages. */
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) { struct ipcm_cookie ipc; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); struct flowi4 fl4; struct sock *sk; struct inet_sock *inet; __be32 daddr, saddr; u32 mark = IP4_REPLY_MARK(net, skb->mark); int type = icmp_param->data.icmph.type; int code = icmp_param->data.icmph.code; if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) return; /* Needed by both icmp_global_allow and icmp_xmit_lock */ local_bh_disable(); /* global icmp_msgs_per_sec */ if (!icmpv4_global_allow(net, type, code)) goto out_bh_enable; sk = icmp_xmit_lock(net); if (!sk) goto out_bh_enable; inet = inet_sk(sk); icmp_param->data.icmph.checksum = 0; inet->tos = ip_hdr(skb)->tos; sk->sk_mark = mark; daddr = ipc.addr = ip_hdr(skb)->saddr; saddr = fib_compute_spec_dst(skb); ipc.opt = NULL; ipc.tx_flags = 0; ipc.ttl = 0; ipc.tos = -1; if (icmp_param->replyopts.opt.opt.optlen) { ipc.opt = &icmp_param->replyopts.opt; if (ipc.opt->opt.srr) daddr = icmp_param->replyopts.opt.opt.faddr; } memset(&fl4, 0, sizeof(fl4)); fl4.daddr = daddr; fl4.saddr = saddr; fl4.flowi4_mark = mark; fl4.flowi4_uid = sock_net_uid(net, NULL); fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); fl4.flowi4_proto = IPPROTO_ICMP; fl4.flowi4_oif = l3mdev_master_ifindex(skb->dev); security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) icmp_push_reply(icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: icmp_xmit_unlock(sk); out_bh_enable: local_bh_enable(); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13732.01%1020.41%
David S. Miller8118.93%1122.45%
Jesper Dangaard Brouer5011.68%24.08%
Denis V. Lunev4310.05%48.16%
Lorenzo Colitti358.18%24.08%
Eric Dumazet204.67%36.12%
Francesco Fusco133.04%12.04%
David Ahern112.57%24.08%
Venkat Yekkirala71.64%12.04%
Changli Gao61.40%12.04%
Arnaldo Carvalho de Melo51.17%24.08%
Patrick Ohly51.17%12.04%
Hideaki Yoshifuji / 吉藤英明30.70%12.04%
Linus Torvalds30.70%12.04%
Pavel Emelyanov20.47%12.04%
Paolo Abeni20.47%12.04%
Al Viro10.23%12.04%
Oliver Hartkopp10.23%12.04%
Ian Morris10.23%12.04%
Alexey Kuznetsov10.23%12.04%
Simon Horman10.23%12.04%
Total428100.00%49100.00%


static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, struct sk_buff *skb_in, const struct iphdr *iph, __be32 saddr, u8 tos, u32 mark, int type, int code, struct icmp_bxm *param) { struct rtable *rt, *rt2; struct flowi4 fl4_dec; int err; memset(fl4, 0, sizeof(*fl4)); fl4->daddr = (param->replyopts.opt.opt.srr ? param->replyopts.opt.opt.faddr : iph->saddr); fl4->saddr = saddr; fl4->flowi4_mark = mark; fl4->flowi4_uid = sock_net_uid(net, NULL); fl4->flowi4_tos = RT_TOS(tos); fl4->flowi4_proto = IPPROTO_ICMP; fl4->fl4_icmp_type = type; fl4->fl4_icmp_code = code; fl4->flowi4_oif = l3mdev_master_ifindex(skb_dst(skb_in)->dev); security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4)); rt = ip_route_output_key_hash(net, fl4, skb_in); if (IS_ERR(rt)) return rt; /* No need to clone since we're just using its address. */ rt2 = rt; rt = (struct rtable *) xfrm_lookup(net, &rt->dst, flowi4_to_flowi(fl4), NULL, 0); if (!IS_ERR(rt)) { if (rt != rt2) return rt; } else if (PTR_ERR(rt) == -EPERM) { rt = NULL; } else return rt; err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET); if (err) goto relookup_failed; if (inet_addr_type_dev_table(net, skb_dst(skb_in)->dev, fl4_dec.saddr) == RTN_LOCAL) { rt2 = __ip_route_output_key(net, &fl4_dec); if (IS_ERR(rt2)) err = PTR_ERR(rt2); } else { struct flowi4 fl4_2 = {}; unsigned long orefdst; fl4_2.daddr = fl4_dec.saddr; rt2 = ip_route_output_key(net, &fl4_2); if (IS_ERR(rt2)) { err = PTR_ERR(rt2); goto relookup_failed; } /* Ugh! */ orefdst = skb_in->_skb_refdst; /* save old refdst */ skb_dst_set(skb_in, NULL); err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, RT_TOS(tos), rt2->dst.dev); dst_release(&rt2->dst); rt2 = skb_rtable(skb_in); skb_in->_skb_refdst = orefdst; /* restore old refdst */ } if (err) goto relookup_failed; rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, flowi4_to_flowi(&fl4_dec), NULL, XFRM_LOOKUP_ICMP); if (!IS_ERR(rt2)) { dst_release(&rt->dst); memcpy(fl4, &fl4_dec, sizeof(*fl4)); rt = rt2; } else if (PTR_ERR(rt2) == -EPERM) { if (rt) dst_release(&rt->dst); return rt2; } else { err = PTR_ERR(rt2); goto relookup_failed; } return rt; relookup_failed: if (rt) return rt; return ERR_PTR(err); }

Contributors

PersonTokensPropCommitsCommitProp
David S. Miller43875.13%923.68%
Linus Torvalds (pre-git)437.38%513.16%
David Ahern233.95%513.16%
Lorenzo Colitti203.43%25.26%
Patrick McHardy101.72%12.63%
Eric Dumazet101.72%37.89%
J. Simonetti71.20%12.63%
Thomas Graf71.20%12.63%
Linus Torvalds71.20%12.63%
Denis V. Lunev61.03%37.89%
Arnaldo Carvalho de Melo50.86%37.89%
Peter Christensen30.51%12.63%
Hideaki Yoshifuji / 吉藤英明20.34%12.63%
Eric W. Biedermann10.17%12.63%
Pavel Emelyanov10.17%12.63%
Total583100.00%38100.00%

/* * Send an ICMP message in response to a situation * * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. * MAY send more (we do). * MUST NOT change this header information. * MUST NOT reply to a multicast/broadcast IP address. * MUST NOT reply to a multicast/broadcast MAC address. * MUST reply to only the first fragment. */
void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) { struct iphdr *iph; int room; struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); struct ipcm_cookie ipc; struct flowi4 fl4; __be32 saddr; u8 tos; u32 mark; struct net *net; struct sock *sk; if (!rt) goto out; net = dev_net(rt->dst.dev); /* * Find the original header. It is expected to be valid, of course. * Check this, icmp_send is called from the most obscure devices * sometimes. */ iph = ip_hdr(skb_in); if ((u8 *)iph < skb_in->head || (skb_network_header(skb_in) + sizeof(*iph)) > skb_tail_pointer(skb_in)) goto out; /* * No replies to physical multicast/broadcast */ if (skb_in->pkt_type != PACKET_HOST) goto out; /* * Now check at the protocol level */ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) goto out; /* * Only reply to fragment 0. We byte re-order the constant * mask for efficiency. */ if (iph->frag_off & htons(IP_OFFSET)) goto out; /* * If we send an ICMP error to an ICMP error a mess would result.. */ if (icmp_pointers[type].error) { /* * We are an error, check if we are replying to an * ICMP error */ if (iph->protocol == IPPROTO_ICMP) { u8 _inner_type, *itp; itp = skb_header_pointer(skb_in, skb_network_header(skb_in) + (iph->ihl << 2) + offsetof(struct icmphdr, type) - skb_in->data, sizeof(_inner_type), &_inner_type); if (!itp) goto out; /* * Assume any unknown ICMP type is an error. This * isn't specified by the RFC, but think about it.. */ if (*itp > NR_ICMP_TYPES || icmp_pointers[*itp].error) goto out; } } /* Needed by both icmp_global_allow and icmp_xmit_lock */ local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless * incoming dev is loopback. If outgoing dev change to not be * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) */ if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && !icmpv4_global_allow(net, type, code)) goto out_bh_enable; sk = icmp_xmit_lock(net); if (!sk) goto out_bh_enable; /* * Construct source address and options. */ saddr = iph->daddr; if (!(rt->rt_flags & RTCF_LOCAL)) { struct net_device *dev = NULL; rcu_read_lock(); if (rt_is_input_route(rt) && net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) dev = dev_get_by_index_rcu(net, inet_iif(skb_in)); if (dev) saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); else saddr = 0; rcu_read_unlock(); } tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | IPTOS_PREC_INTERNETCONTROL) : iph->tos; mark = IP4_REPLY_MARK(net, skb_in->mark); if (ip_options_echo(net, &icmp_param.replyopts.opt.opt, skb_in)) goto out_unlock; /* * Prepare data for ICMP header. */ icmp_param.data.icmph.type = type; icmp_param.data.icmph.code = code; icmp_param.data.icmph.un.gateway = info; icmp_param.data.icmph.checksum = 0; icmp_param.skb = skb_in; icmp_param.offset = skb_network_offset(skb_in); inet_sk(sk)->tos = tos; sk->sk_mark = mark; ipc.addr = iph->saddr; ipc.opt = &icmp_param.replyopts.opt; ipc.tx_flags = 0; ipc.ttl = 0; ipc.tos = -1; rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark, type, code, &icmp_param); if (IS_ERR(rt)) goto out_unlock; /* peer icmp_ratelimit */ if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) goto ende; /* RFC says return as much as we can without exceeding 576 bytes. */ room = dst_mtu(&rt->dst); if (room > 576) room = 576; room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; room -= sizeof(struct icmphdr); icmp_param.data_len = skb_in->len - icmp_param.offset; if (icmp_param.data_len > room) icmp_param.data_len = room; icmp_param.head_len = sizeof(struct icmphdr); icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); ende: ip_rt_put(rt); out_unlock: icmp_xmit_unlock(sk); out_bh_enable: local_bh_enable(); out:; }

Contributors

PersonTokensPropCommitsCommitProp
David S. Miller39753.43%612.77%
Linus Torvalds (pre-git)10514.13%1021.28%
Jesper Dangaard Brouer739.83%48.51%
Herbert Xu648.61%48.51%
Lorenzo Colitti222.96%12.13%
Eric Dumazet152.02%48.51%
Linus Torvalds152.02%12.13%
Francesco Fusco131.75%12.13%
Denis V. Lunev70.94%48.51%
Simon Horman60.81%12.13%
Arnaldo Carvalho de Melo60.81%24.26%
Alexey Kuznetsov40.54%24.26%
Venkat Yekkirala40.54%12.13%
Ulrich Weber40.54%12.13%
Paolo Abeni20.27%12.13%
Pavel Emelyanov20.27%12.13%
Alexey Dobriyan20.27%12.13%
Eric W. Biedermann10.13%12.13%
Ian Morris10.13%12.13%
Total743100.00%47100.00%

EXPORT_SYMBOL(icmp_send);
static void icmp_socket_deliver(struct sk_buff *skb, u32 info) { const struct iphdr *iph = (const struct iphdr *) skb->data; const struct net_protocol *ipprot; int protocol = iph->protocol; /* Checkin full IP header plus 8 bytes of protocol to * avoid additional coding at protocol handlers. */ if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) { __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); return; } raw_icmp_error(skb, protocol, info); ipprot = rcu_dereference(inet_protos[protocol]); if (ipprot && ipprot->err_handler) ipprot->err_handler(skb, info); }

Contributors

PersonTokensPropCommitsCommitProp
David S. Miller8677.48%337.50%
Duan Jiong1311.71%112.50%
Linus Torvalds (pre-git)109.01%225.00%
Eric Dumazet21.80%225.00%
Total111100.00%8100.00%


static bool icmp_tag_validation(int proto) { bool ok; rcu_read_lock(); ok = rcu_dereference(inet_protos[proto])->icmp_strict_tag_validation; rcu_read_unlock(); return ok; }

Contributors

PersonTokensPropCommitsCommitProp
Hannes Frederic Sowa33100.00%1100.00%
Total33100.00%1100.00%

/* * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, ICMP_QUENCH, and * ICMP_PARAMETERPROB. */
static bool icmp_unreach(struct sk_buff *skb) { const struct iphdr *iph; struct icmphdr *icmph; struct net *net; u32 info = 0; net = dev_net(skb_dst(skb)->dev); /* * Incomplete header ? * Only checks for the IP header, there should be an * additional check for longer headers in upper levels. */ if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out_err; icmph = icmp_hdr(skb); iph = (const struct iphdr *)skb->data; if (iph->ihl < 5) /* Mangled header, drop. */ goto out_err; if (icmph->type == ICMP_DEST_UNREACH) { switch (icmph->code & 15) { case ICMP_NET_UNREACH: case ICMP_HOST_UNREACH: case ICMP_PROT_UNREACH: case ICMP_PORT_UNREACH: break; case ICMP_FRAG_NEEDED: /* for documentation of the ip_no_pmtu_disc * values please see * Documentation/networking/ip-sysctl.txt */ switch (net->ipv4.sysctl_ip_no_pmtu_disc) { default: net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n", &iph->daddr); break; case 2: goto out; case 3: if (!icmp_tag_validation(iph->protocol)) goto out; /* fall through */ case 0: info = ntohs(icmph->un.frag.mtu); } break; case ICMP_SR_FAILED: net_dbg_ratelimited("%pI4: Source Route Failed\n", &iph->daddr); break; default: break; } if (icmph->code > NR_ICMP_UNREACH) goto out; } else if (icmph->type == ICMP_PARAMETERPROB) info = ntohl(icmph->un.gateway) >> 24; /* * Throw it at our lower layers * * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed * header. * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the * transport layer. * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to * transport layer. */ /* * Check the other end isn't violating RFC 1122. Some routers send * bogus responses to broadcast frames. If you see this message * first check your netmask matches at both ends, if it does then * get the other vendor to fix their kit. */ if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) { net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n", &ip_hdr(skb)->saddr, icmph->type, icmph->code, &iph->daddr, skb->dev->name); goto out; } icmp_socket_deliver(skb, info); out: return true; out_err: __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); return false; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11735.67%1535.71%
Linus Torvalds6419.51%12.38%
Hannes Frederic Sowa3610.98%24.76%
Harvey Harrison237.01%12.38%
Arnaldo Carvalho de Melo164.88%24.76%
Joe Perches164.88%49.52%
David S. Miller144.27%24.76%
Denis V. Lunev72.13%12.38%
Rick Jones72.13%12.38%
Pavel Emelyanov61.83%37.14%
David Ahern51.52%12.38%
Eric Dumazet51.52%37.14%
Maciej Soltysiak41.22%12.38%
Hideaki Yoshifuji / 吉藤英明41.22%24.76%
Andi Kleen20.61%12.38%
Lucas De Marchi10.30%12.38%
Eric W. Biedermann10.30%12.38%
Total328100.00%42100.00%

/* * Handle ICMP_REDIRECT. */
static bool icmp_redirect(struct sk_buff *skb) { if (skb->len < sizeof(struct iphdr)) { __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); return false; } if (!pskb_may_pull(skb, sizeof(struct iphdr))) { /* there aught to be a stat */ return false; } icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway); return true; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2025.97%333.33%
Linus Torvalds1620.78%111.11%
David S. Miller1418.18%222.22%
Rick Jones1316.88%111.11%
Vasiliy Kulikov1316.88%111.11%
Eric Dumazet11.30%111.11%
Total77100.00%9100.00%

/* * Handle ICMP_ECHO ("ping") requests. * * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo * requests. * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be * included in the reply. * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring * echo requests, MUST have default=NOT. * See also WRT handling of options once they are done and working. */
static bool icmp_echo(struct sk_buff *skb) { struct net *net; net = dev_net(skb_dst(skb)->dev); if (!net->ipv4.sysctl_icmp_echo_ignore_all) { struct icmp_bxm icmp_param; icmp_param.data.icmph = *icmp_hdr(skb); icmp_param.data.icmph.type = ICMP_ECHOREPLY; icmp_param.skb = skb; icmp_param.offset = 0; icmp_param.data_len = skb->len; icmp_param.head_len = sizeof(struct icmphdr); icmp_reply(&icmp_param, skb); } /* should there be an ICMP stat for ignored echos? */ return true; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5349.53%646.15%
Linus Torvalds2523.36%17.69%
Pavel Emelyanov1816.82%323.08%
Rick Jones54.67%17.69%
Arnaldo Carvalho de Melo32.80%17.69%
Eric Dumazet32.80%17.69%
Total107100.00%13100.00%

/* * Handle ICMP Timestamp requests. * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. * SHOULD be in the kernel for minimum random latency. * MUST be accurate to a few minutes. * MUST be updated at least at 15Hz. */
static bool icmp_timestamp(struct sk_buff *skb) { struct icmp_bxm icmp_param; /* * Too short. */ if (skb->len < 4) goto out_err; /* * Fill in the current time as ms since midnight UT: */ icmp_param.data.times[1] = inet_current_timestamp(); icmp_param.data.times[2] = icmp_param.data.times[1]; if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) BUG(); icmp_param.data.icmph = *icmp_hdr(skb); icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; icmp_param.data.icmph.code = 0; icmp_param.skb = skb; icmp_param.offset = 0; icmp_param.data_len = 0; icmp_param.head_len = sizeof(struct icmphdr) + 12; icmp_reply(&icmp_param, skb); return true; out_err: __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); return false; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8649.14%950.00%
Linus Torvalds5632.00%15.56%
Arnaldo Carvalho de Melo126.86%211.11%
Rick Jones74.00%15.56%
Pavel Emelyanov74.00%15.56%
Eric Dumazet42.29%211.11%
Deepa Dinamani21.14%15.56%
Hideaki Yoshifuji / 吉藤英明10.57%15.56%
Total175100.00%18100.00%


static bool icmp_discard(struct sk_buff *skb) { /* pretend it was a success */ return true; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)853.33%375.00%
Rick Jones746.67%125.00%
Total15100.00%4100.00%

/* * Deal with incoming ICMP packets. */
int icmp_rcv(struct sk_buff *skb) { struct icmphdr *icmph; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); bool success; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { struct sec_path *sp = skb_sec_path(skb); int nh; if (!(sp && sp->xvec[sp->len - 1]->props.flags & XFRM_STATE_ICMP)) goto drop; if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) goto drop; nh = skb_network_offset(skb); skb_set_network_header(skb, sizeof(*icmph)); if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) goto drop; skb_set_network_header(skb, nh); } __ICMP_INC_STATS(net, ICMP_MIB_INMSGS); if (skb_checksum_simple_validate(skb)) goto csum_error; if (!pskb_pull(skb, sizeof(*icmph))) goto error; icmph = icmp_hdr(skb); ICMPMSGIN_INC_STATS(net, icmph->type); /* * 18 is the highest 'known' ICMP type. Anything else is a mystery * * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently * discarded. */ if (icmph->type > NR_ICMP_TYPES) goto error; /* * Parse the ICMP message */ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { /* * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be * silently ignored (we let user decide with a sysctl). * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently * discarded if to broadcast/multicast. */ if ((icmph->type == ICMP_ECHO || icmph->type == ICMP_TIMESTAMP) && net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { goto error; } if (icmph->type != ICMP_ECHO && icmph->type != ICMP_TIMESTAMP && icmph->type != ICMP_ADDRESS && icmph->type != ICMP_ADDRESSREPLY) { goto error; } } success = icmp_pointers[icmph->type].handler(skb); if (success) { consume_skb(skb); return NET_RX_SUCCESS; } drop: kfree_skb(skb); return NET_RX_DROP; csum_error: __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS); error: __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); goto drop; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)12435.03%1334.21%
Herbert Xu11733.05%410.53%
Pavel Emelyanov246.78%513.16%
Rick Jones185.08%12.63%
Eric Dumazet164.52%410.53%
Linus Torvalds154.24%12.63%
Alexey Kuznetsov123.39%25.26%
Alexey Dobriyan102.82%12.63%
Arnaldo Carvalho de Melo71.98%37.89%
David L Stevens61.69%12.63%
Zhang Shengju20.56%12.63%
Hideaki Yoshifuji / 吉藤英明20.56%12.63%
Tom Herbert10.28%12.63%
Total354100.00%38100.00%


void icmp_err(struct sk_buff *skb, u32 info) { struct iphdr *iph = (struct iphdr *)skb->data; int offset = iph->ihl<<2; struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset); int type = icmp_hdr(skb)->type; int code = icmp_hdr(skb)->code; struct net *net = dev_net(skb->dev); /* * Use ping_err to handle all icmp errors except those * triggered by ICMP_ECHOREPLY which sent from kernel. */ if (icmph->type != ICMP_ECHOREPLY) { ping_err(skb, offset, info); return; } if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0); else if (type == ICMP_REDIRECT) ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Li Wei14492.31%150.00%
Lorenzo Colitti127.69%150.00%
Total156100.00%2100.00%

/* * This table is the definition of how we handle ICMP. */ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { [ICMP_ECHOREPLY] = { .handler = ping_rcv, }, [1] = { .handler = icmp_discard, .error = 1, }, [2] = { .handler = icmp_discard, .error = 1, }, [ICMP_DEST_UNREACH] = { .handler = icmp_unreach, .error = 1, }, [ICMP_SOURCE_QUENCH] = { .handler = icmp_unreach, .error = 1, }, [ICMP_REDIRECT] = { .handler = icmp_redirect, .error = 1, }, [6] = { .handler = icmp_discard, .error = 1, }, [7] = { .handler = icmp_discard, .error = 1, }, [ICMP_ECHO] = { .handler = icmp_echo, }, [9] = { .handler = icmp_discard, .error = 1, }, [10] = { .handler = icmp_discard, .error = 1, }, [ICMP_TIME_EXCEEDED] = { .handler = icmp_unreach, .error = 1, }, [ICMP_PARAMETERPROB] = { .handler = icmp_unreach, .error = 1, }, [ICMP_TIMESTAMP] = { .handler = icmp_timestamp, }, [ICMP_TIMESTAMPREPLY] = { .handler = icmp_discard, }, [ICMP_INFO_REQUEST] = { .handler = icmp_discard, }, [ICMP_INFO_REPLY] = { .handler = icmp_discard, }, [ICMP_ADDRESS] = { .handler = icmp_discard, }, [ICMP_ADDRESSREPLY] = { .handler = icmp_discard, }, };
static void __net_exit icmp_sk_exit(struct net *net) { int i; for_each_possible_cpu(i) inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i)); free_percpu(net->ipv4.icmp_sk); net->ipv4.icmp_sk = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Denis V. Lunev4486.27%571.43%
Eric Dumazet611.76%114.29%
Linus Torvalds (pre-git)11.96%114.29%
Total51100.00%7100.00%


static int __net_init icmp_sk_init(struct net *net) { int i, err; net->ipv4.icmp_sk = alloc_percpu(struct sock *); if (!net->ipv4.icmp_sk) return -ENOMEM; for_each_possible_cpu(i) { struct sock *sk; err = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, IPPROTO_ICMP, net); if (err < 0) goto fail; *per_cpu_ptr(net->ipv4.icmp_sk, i) = sk; /* Enough space for 2 64K ICMP packets, including * sk_buff/skb_shared_info struct overhead. */ sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); /* * Speedup sock_wfree() */ sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; } /* Control parameters for ECHO replies. */ net->ipv4.sysctl_icmp_echo_ignore_all = 0; net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; /* Control parameter - ignore bogus broadcast responses? */ net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; /* * Configurable global rate limit. * * ratelimit defines tokens/packet consumed for dst->rate_token * bucket ratemask defines which icmp types are ratelimited by * setting it's bit position. * * default: * dest unreachable (3), source quench (4), * time exceeded (11), parameter problem (12) */ net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; net->ipv4.sysctl_icmp_ratemask = 0x1818; net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; return 0; fail: for_each_possible_cpu(i) inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i)); free_percpu(net->ipv4.icmp_sk); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Denis V. Lunev8338.97%622.22%
Pavel Emelyanov5324.88%13.70%
Eric Dumazet2411.27%311.11%
Linus Torvalds (pre-git)198.92%829.63%
David S. Miller177.98%311.11%
Linus Torvalds115.16%27.41%
John Hawkes31.41%13.70%
Adrian Bunk10.47%13.70%
Arnaldo Carvalho de Melo10.47%13.70%
Kamezawa Hiroyuki10.47%13.70%
Total213100.00%27100.00%

static struct pernet_operations __net_initdata icmp_sk_ops = { .init = icmp_sk_init, .exit = icmp_sk_exit, };
int __init icmp_init(void) { return register_pernet_subsys(&icmp_sk_ops); }

Contributors

PersonTokensPropCommitsCommitProp
Denis V. Lunev1493.33%150.00%
Eric W. Biedermann16.67%150.00%
Total15100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)117623.54%4722.27%
David S. Miller110422.10%2712.80%
Eric Dumazet3476.95%178.06%
Denis V. Lunev2885.77%136.16%
Arnaldo Carvalho de Melo2805.61%94.27%
Linus Torvalds2645.29%52.37%
Jesper Dangaard Brouer2474.94%41.90%
Herbert Xu1843.68%73.32%
Alexey Kuznetsov1593.18%52.37%
Li Wei1442.88%10.47%
Pavel Emelyanov1312.62%94.27%
Rusty Russell1242.48%20.95%
Lorenzo Colitti891.78%31.42%
Hannes Frederic Sowa691.38%20.95%
Rick Jones581.16%10.47%
David Ahern511.02%62.84%
Patrick McHardy440.88%31.42%
Francesco Fusco260.52%10.47%
Harvey Harrison230.46%10.47%
Joe Perches230.46%41.90%
Vasiliy Kulikov170.34%10.47%
Hideaki Yoshifuji / 吉藤英明160.32%20.95%
Alexey Dobriyan130.26%31.42%
Duan Jiong130.26%10.47%
Venkat Yekkirala110.22%10.47%
David L Stevens90.18%10.47%
J. Simonetti70.14%10.47%
Simon Horman70.14%20.95%
Thomas Graf70.14%10.47%
Changli Gao60.12%10.47%
Patrick Ohly50.10%10.47%
Paolo Abeni40.08%10.47%
Al Viro40.08%41.90%
Ulrich Weber40.08%10.47%
Eric W. Biedermann40.08%31.42%
Maciej Soltysiak40.08%10.47%
Neal Cardwell40.08%10.47%
John Hawkes30.06%10.47%
Peter Christensen30.06%10.47%
Tejun Heo30.06%10.47%
Zhang Shengju20.04%10.47%
Ian Morris20.04%10.47%
Adrian Bunk20.04%20.95%
Deepa Dinamani20.04%10.47%
Arjan van de Ven20.04%10.47%
Andi Kleen20.04%10.47%
Randy Dunlap10.02%10.47%
Alan Cox10.02%10.47%
Lucas De Marchi10.02%10.47%
Tom Herbert10.02%10.47%
Kamezawa Hiroyuki10.02%10.47%
Oliver Hartkopp10.02%10.47%
Rami Rosen10.02%10.47%
Ravikiran G. Thirumalai10.02%10.47%
Total4995100.00%211100.00%
Directory: net/ipv4
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