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Release 4.11 net/ipv4/netfilter/nf_conntrack_proto_icmp.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/types.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <linux/in.h>
#include <linux/icmp.h>
#include <linux/seq_file.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_log.h>


static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;


static inline struct nf_icmp_net *icmp_pernet(struct net *net) { return &net->ct.nf_ct_proto.icmp; }

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PersonTokensPropCommitsCommitProp
Gao Feng24100.00%1100.00%
Total24100.00%1100.00%


static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff, struct net *net, struct nf_conntrack_tuple *tuple) { const struct icmphdr *hp; struct icmphdr _hdr; hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); if (hp == NULL) return false; tuple->dst.u.icmp.type = hp->type; tuple->src.u.icmp.id = hp->un.echo.id; tuple->dst.u.icmp.code = hp->code; return true; }

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PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai9888.29%125.00%
Jan Engelhardt87.21%250.00%
Eric W. Biedermann54.50%125.00%
Total111100.00%4100.00%

/* Add 1; spaces filled with 0. */ static const u_int8_t invmap[] = { [ICMP_ECHO] = ICMP_ECHOREPLY + 1, [ICMP_ECHOREPLY] = ICMP_ECHO + 1, [ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1, [ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1, [ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1, [ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1, [ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1, [ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1 };
static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *orig) { if (orig->dst.u.icmp.type >= sizeof(invmap) || !invmap[orig->dst.u.icmp.type]) return false; tuple->src.u.icmp.id = orig->src.u.icmp.id; tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1; tuple->dst.u.icmp.code = orig->dst.u.icmp.code; return true; }

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PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai10184.87%133.33%
Pablo Neira Ayuso1512.61%133.33%
Jan Engelhardt32.52%133.33%
Total119100.00%3100.00%

/* Print out the per-protocol part of the tuple. */
static void icmp_print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple) { seq_printf(s, "type=%u code=%u id=%u ", tuple->dst.u.icmp.type, tuple->dst.u.icmp.code, ntohs(tuple->src.u.icmp.id)); }

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PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai5596.49%150.00%
Joe Perches23.51%150.00%
Total57100.00%2100.00%


static unsigned int *icmp_get_timeouts(struct net *net) { return &icmp_pernet(net)->timeout; }

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Pablo Neira Ayuso1672.73%150.00%
Gao Feng627.27%150.00%
Total22100.00%2100.00%

/* Returns verdict for packet, or -1 for invalid. */
static int icmp_packet(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff, enum ip_conntrack_info ctinfo, u_int8_t pf, unsigned int hooknum, unsigned int *timeout) { /* Do not immediately delete the connection after the first successful reply to avoid excessive conntrackd traffic and also to handle correctly ICMP echo reply duplicates. */ nf_ct_refresh_acct(ct, ctinfo, skb, *timeout); return NF_ACCEPT; }

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PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai4483.02%125.00%
Pablo Neira Ayuso713.21%125.00%
Jan Yenya Kasprzak11.89%125.00%
Jan Engelhardt11.89%125.00%
Total53100.00%4100.00%

/* Called when a new connection for this protocol found. */
static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff, unsigned int *timeouts) { static const u_int8_t valid_new[] = { [ICMP_ECHO] = 1, [ICMP_TIMESTAMP] = 1, [ICMP_INFO_REQUEST] = 1, [ICMP_ADDRESS] = 1 }; if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) || !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) { /* Can't create a new ICMP `conn' with this. */ pr_debug("icmp: can't create new conn with type %u\n", ct->tuplehash[0].tuple.dst.u.icmp.type); nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple); return false; } return true; }

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PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai13189.12%114.29%
Patrick McHardy64.08%228.57%
Pablo Neira Ayuso64.08%228.57%
Jan Engelhardt42.72%228.57%
Total147100.00%7100.00%

/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
static int icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, unsigned int hooknum) { struct nf_conntrack_tuple innertuple, origtuple; const struct nf_conntrack_l4proto *innerproto; const struct nf_conntrack_tuple_hash *h; const struct nf_conntrack_zone *zone; enum ip_conntrack_info ctinfo; struct nf_conntrack_zone tmp; NF_CT_ASSERT(!skb_nfct(skb)); zone = nf_ct_zone_tmpl(tmpl, skb, &tmp); /* Are they talking about one of our connections? */ if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb) + ip_hdrlen(skb) + sizeof(struct icmphdr), PF_INET, net, &origtuple)) { pr_debug("icmp_error_message: failed to get tuple\n"); return -NF_ACCEPT; } /* rcu_read_lock()ed by nf_hook_thresh */ innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum); /* Ordinarily, we'd expect the inverted tupleproto, but it's been preserved inside the ICMP. */ if (!nf_ct_invert_tuple(&innertuple, &origtuple, &nf_conntrack_l3proto_ipv4, innerproto)) { pr_debug("icmp_error_message: no match\n"); return -NF_ACCEPT; } ctinfo = IP_CT_RELATED; h = nf_conntrack_find_get(net, zone, &innertuple); if (!h) { pr_debug("icmp_error_message: no match\n"); return -NF_ACCEPT; } if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) ctinfo += IP_CT_IS_REPLY; /* Update skb to refer to this connection */ nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo); return NF_ACCEPT; }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai16171.56%211.76%
Daniel Borkmann208.89%211.76%
Florian Westphal135.78%317.65%
Patrick McHardy125.33%211.76%
Alexey Dobriyan83.56%211.76%
Arnaldo Carvalho de Melo31.33%15.88%
Martin Josefsson20.89%15.88%
Jan Engelhardt20.89%15.88%
Eric W. Biedermann20.89%15.88%
Aaron Conole10.44%15.88%
Hideaki Yoshifuji / 吉藤英明10.44%15.88%
Total225100.00%17100.00%

/* Small and modified version of icmp_rcv */
static int icmp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, unsigned int dataoff, u8 pf, unsigned int hooknum) { const struct icmphdr *icmph; struct icmphdr _ih; /* Not enough header? */ icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih); if (icmph == NULL) { if (LOG_INVALID(net, IPPROTO_ICMP)) nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL, "nf_ct_icmp: short packet "); return -NF_ACCEPT; } /* See ip_conntrack_proto_tcp.c */ if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && nf_ip_checksum(skb, hooknum, dataoff, 0)) { if (LOG_INVALID(net, IPPROTO_ICMP)) nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL, "nf_ct_icmp: bad HW ICMP checksum "); return -NF_ACCEPT; } /* * 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) { if (LOG_INVALID(net, IPPROTO_ICMP)) nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL, "nf_ct_icmp: invalid ICMP type "); return -NF_ACCEPT; } /* Need to track icmp error message? */ if (icmph->type != ICMP_DEST_UNREACH && icmph->type != ICMP_SOURCE_QUENCH && icmph->type != ICMP_TIME_EXCEEDED && icmph->type != ICMP_PARAMETERPROB && icmph->type != ICMP_REDIRECT) return NF_ACCEPT; return icmp_error_message(net, tmpl, skb, hooknum); }

Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai20480.95%17.69%
Alexey Dobriyan187.14%323.08%
Patrick McHardy155.95%538.46%
Gao Feng62.38%17.69%
Jan Engelhardt51.98%17.69%
Arnaldo Carvalho de Melo31.19%17.69%
Florian Westphal10.40%17.69%
Total252100.00%13100.00%

#if IS_ENABLED(CONFIG_NF_CT_NETLINK) #include <linux/netfilter/nfnetlink.h> #include <linux/netfilter/nfnetlink_conntrack.h>
static int icmp_tuple_to_nlattr(struct sk_buff *skb, const struct nf_conntrack_tuple *t) { if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) || nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) || nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code)) goto nla_put_failure; return 0; nla_put_failure: return -1; }

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PersonTokensPropCommitsCommitProp
Pablo Neira Ayuso6984.15%125.00%
David S. Miller1113.41%125.00%
Patrick McHardy22.44%250.00%
Total82100.00%4100.00%

static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = { [CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 }, [CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 }, [CTA_PROTO_ICMP_ID] = { .type = NLA_U16 }, };
static int icmp_nlattr_to_tuple(struct nlattr *tb[], struct nf_conntrack_tuple *tuple) { if (!tb[CTA_PROTO_ICMP_TYPE] || !tb[CTA_PROTO_ICMP_CODE] || !tb[CTA_PROTO_ICMP_ID]) return -EINVAL; tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]); tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]); tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]); if (tuple->dst.u.icmp.type >= sizeof(invmap) || !invmap[tuple->dst.u.icmp.type]) return -EINVAL; return 0; }

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PersonTokensPropCommitsCommitProp
Pablo Neira Ayuso12896.24%125.00%
Patrick McHardy53.76%375.00%
Total133100.00%4100.00%


static int icmp_nlattr_tuple_size(void) { return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1); }

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Holger Eitzenberger18100.00%1100.00%
Total18100.00%1100.00%

#endif #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) #include <linux/netfilter/nfnetlink.h> #include <linux/netfilter/nfnetlink_cttimeout.h>
static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[], struct net *net, void *data) { unsigned int *timeout = data; struct nf_icmp_net *in = icmp_pernet(net); if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) { *timeout = ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ; } else { /* Set default ICMP timeout. */ *timeout = in->timeout; } return 0; }

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PersonTokensPropCommitsCommitProp
Pablo Neira Ayuso5976.62%150.00%
Gao Feng1823.38%150.00%
Total77100.00%2100.00%


static int icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) { const unsigned int *timeout = data; if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ))) goto nla_put_failure; return 0; nla_put_failure: return -ENOSPC; }

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PersonTokensPropCommitsCommitProp
Pablo Neira Ayuso4686.79%150.00%
David S. Miller713.21%150.00%
Total53100.00%2100.00%

static const struct nla_policy icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = { [CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 }, }; #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ #ifdef CONFIG_SYSCTL static struct ctl_table icmp_sysctl_table[] = { { .procname = "nf_conntrack_icmp_timeout", .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { } }; #endif /* CONFIG_SYSCTL */
static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn, struct nf_icmp_net *in) { #ifdef CONFIG_SYSCTL pn->ctl_table = kmemdup(icmp_sysctl_table, sizeof(icmp_sysctl_table), GFP_KERNEL); if (!pn->ctl_table) return -ENOMEM; pn->ctl_table[0].data = &in->timeout; #endif return 0; }

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Gao Feng65100.00%3100.00%
Total65100.00%3100.00%


static int icmp_init_net(struct net *net, u_int16_t proto) { struct nf_icmp_net *in = icmp_pernet(net); struct nf_proto_net *pn = &in->pn; in->timeout = nf_ct_icmp_timeout; return icmp_kmemdup_sysctl_table(pn, in); }

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PersonTokensPropCommitsCommitProp
Gao Feng48100.00%1100.00%
Total48100.00%1100.00%


static struct nf_proto_net *icmp_get_net_proto(struct net *net) { return &net->ct.nf_ct_proto.icmp.pn; }

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PersonTokensPropCommitsCommitProp
Pablo Neira Ayuso25100.00%1100.00%
Total25100.00%1100.00%

struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly = { .l3proto = PF_INET, .l4proto = IPPROTO_ICMP, .name = "icmp", .pkt_to_tuple = icmp_pkt_to_tuple, .invert_tuple = icmp_invert_tuple, .print_tuple = icmp_print_tuple, .packet = icmp_packet, .get_timeouts = icmp_get_timeouts, .new = icmp_new, .error = icmp_error, .destroy = NULL, .me = NULL, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = icmp_tuple_to_nlattr, .nlattr_tuple_size = icmp_nlattr_tuple_size, .nlattr_to_tuple = icmp_nlattr_to_tuple, .nla_policy = icmp_nla_policy, #endif #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) .ctnl_timeout = { .nlattr_to_obj = icmp_timeout_nlattr_to_obj, .obj_to_nlattr = icmp_timeout_obj_to_nlattr, .nlattr_max = CTA_TIMEOUT_ICMP_MAX, .obj_size = sizeof(unsigned int), .nla_policy = icmp_timeout_nla_policy, }, #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ .init_net = icmp_init_net, .get_net_proto = icmp_get_net_proto, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Yasuyuki Kozakai97050.23%23.85%
Pablo Neira Ayuso51426.62%47.69%
Gao Feng1728.91%59.62%
Patrick McHardy1236.37%1630.77%
Alexey Dobriyan261.35%47.69%
Jan Engelhardt231.19%47.69%
Holger Eitzenberger231.19%11.92%
Daniel Borkmann201.04%23.85%
David S. Miller180.93%11.92%
Florian Westphal140.73%35.77%
Eric W. Biedermann80.41%23.85%
Martin Josefsson60.31%11.92%
Arnaldo Carvalho de Melo60.31%11.92%
Joe Perches20.10%11.92%
Duan Jiong20.10%11.92%
Jan Yenya Kasprzak10.05%11.92%
Aaron Conole10.05%11.92%
Brian Haley10.05%11.92%
Hideaki Yoshifuji / 吉藤英明10.05%11.92%
Total1931100.00%52100.00%
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