cregit-Linux how code gets into the kernel

Release 4.8 net/ipv6/udp.c

Directory: net/ipv6
/*
 *      UDP over IPv6
 *      Linux INET6 implementation
 *
 *      Authors:
 *      Pedro Roque             <roque@di.fc.ul.pt>
 *
 *      Based on linux/ipv4/udp.c
 *
 *      Fixes:
 *      Hideaki YOSHIFUJI       :       sin6_scope_id support
 *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
 *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
 *                                      a single port at the same time.
 *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
 *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/udp6 to seq_file.
 *
 *      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.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <asm/uaccess.h>

#include <net/addrconf.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/raw.h>
#include <net/tcp_states.h>
#include <net/ip6_checksum.h>
#include <net/xfrm.h>
#include <net/inet6_hashtables.h>
#include <net/busy_poll.h>
#include <net/sock_reuseport.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <trace/events/skb.h>
#include "udp_impl.h"


static u32 udp6_ehashfn(const struct net *net, const struct in6_addr *laddr, const u16 lport, const struct in6_addr *faddr, const __be16 fport) { static u32 udp6_ehash_secret __read_mostly; static u32 udp_ipv6_hash_secret __read_mostly; u32 lhash, fhash; net_get_random_once(&udp6_ehash_secret, sizeof(udp6_ehash_secret)); net_get_random_once(&udp_ipv6_hash_secret, sizeof(udp_ipv6_hash_secret)); lhash = (__force u32)laddr->s6_addr32[3]; fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); return __inet6_ehashfn(lhash, lport, fhash, fport, udp_ipv6_hash_secret + net_hash_mix(net)); }

Contributors

PersonTokensPropCommitsCommitProp
hannes frederic sowahannes frederic sowa10797.27%250.00%
eric dumazeteric dumazet21.82%125.00%
vladislav yasevichvladislav yasevich10.91%125.00%
Total110100.00%4100.00%


static u32 udp6_portaddr_hash(const struct net *net, const struct in6_addr *addr6, unsigned int port) { unsigned int hash, mix = net_hash_mix(net); if (ipv6_addr_any(addr6)) hash = jhash_1word(0, mix); else if (ipv6_addr_v4mapped(addr6)) hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix); else hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix); return hash ^ port; }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet9898.99%375.00%
brian haleybrian haley11.01%125.00%
Total99100.00%4100.00%


int udp_v6_get_port(struct sock *sk, unsigned short snum) { unsigned int hash2_nulladdr = udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum); unsigned int hash2_partial = udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0); /* precompute partial secondary hash */ udp_sk(sk)->udp_portaddr_hash = hash2_partial; return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr); }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet4866.67%325.00%
pre-gitpre-git1723.61%433.33%
arnaldo carvalho de meloarnaldo carvalho de melo45.56%216.67%
gerrit renkergerrit renker11.39%18.33%
david s. millerdavid s. miller11.39%18.33%
pavel emelianovpavel emelianov11.39%18.33%
Total72100.00%12100.00%


static void udp_v6_rehash(struct sock *sk) { u16 new_hash = udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, inet_sk(sk)->inet_num); udp_lib_rehash(sk, new_hash); }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet41100.00%2100.00%
Total41100.00%2100.00%


static int compute_score(struct sock *sk, struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, unsigned short hnum, int dif) { int score; struct inet_sock *inet; if (!net_eq(sock_net(sk), net) || udp_sk(sk)->udp_port_hash != hnum || sk->sk_family != PF_INET6) return -1; score = 0; inet = inet_sk(sk); if (inet->inet_dport) { if (inet->inet_dport != sport) return -1; score++; } if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) { if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) return -1; score++; } if (!ipv6_addr_any(&sk->sk_v6_daddr)) { if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) return -1; score++; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) return -1; score++; } if (sk->sk_incoming_cpu == raw_smp_processor_id()) score++; return score; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git10950.46%420.00%
eric dumazeteric dumazet5826.85%630.00%
joe perchesjoe perches198.80%15.00%
hideaki yoshifujihideaki yoshifuji115.09%315.00%
pavel emelianovpavel emelianov83.70%15.00%
xuemin suxuemin su31.39%15.00%
arnaldo carvalho de meloarnaldo carvalho de melo31.39%15.00%
balazs scheidlerbalazs scheidler20.93%15.00%
david s. millerdavid s. miller20.93%15.00%
gerrit renkergerrit renker10.46%15.00%
Total216100.00%20100.00%

/* called with rcu_read_lock() */
static struct sock *udp6_lib_lookup2(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, unsigned int hnum, int dif, struct udp_hslot *hslot2, struct sk_buff *skb) { struct sock *sk, *result; int score, badness, matches = 0, reuseport = 0; u32 hash = 0; result = NULL; badness = -1; udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { score = compute_score(sk, net, saddr, sport, daddr, hnum, dif); if (score > badness) { reuseport = sk->sk_reuseport; if (reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); if (result) return result; matches = 1; } result = sk; badness = score; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) result = sk; hash = next_pseudo_random32(hash); } } return result; }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet11251.61%330.00%
tom herberttom herbert7333.64%110.00%
craig gallekcraig gallek2611.98%330.00%
daniel borkmanndaniel borkmann41.84%110.00%
xuemin suxuemin su10.46%110.00%
hannes frederic sowahannes frederic sowa10.46%110.00%
Total217100.00%10100.00%

/* rcu_read_lock() must be held */
struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif, struct udp_table *udptable, struct sk_buff *skb) { struct sock *sk, *result; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; int score, badness, matches = 0, reuseport = 0; u32 hash = 0; if (hslot->count > 10) { hash2 = udp6_portaddr_hash(net, daddr, hnum); slot2 = hash2 & udptable->mask; hslot2 = &udptable->hash2[slot2]; if (hslot->count < hslot2->count) goto begin; result = udp6_lib_lookup2(net, saddr, sport, daddr, hnum, dif, hslot2, skb); if (!result) { unsigned int old_slot2 = slot2; hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum); slot2 = hash2 & udptable->mask; /* avoid searching the same slot again. */ if (unlikely(slot2 == old_slot2)) return result; hslot2 = &udptable->hash2[slot2]; if (hslot->count < hslot2->count) goto begin; result = udp6_lib_lookup2(net, saddr, sport, daddr, hnum, dif, hslot2, skb); } return result; } begin: result = NULL; badness = -1; sk_for_each_rcu(sk, &hslot->head) { score = compute_score(sk, net, saddr, sport, daddr, hnum, dif); if (score > badness) { reuseport = sk->sk_reuseport; if (reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); if (result) return result; matches = 1; } result = sk; badness = score; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) result = sk; hash = next_pseudo_random32(hash); } } return result; }

Contributors

PersonTokensPropCommitsCommitProp
eric dumazeteric dumazet27965.34%637.50%
tom herberttom herbert7216.86%16.25%
craig gallekcraig gallek296.79%318.75%
xuemin suxuemin su214.92%16.25%
pre-gitpre-git184.22%16.25%
daniel borkmanndaniel borkmann40.94%16.25%
balazs scheidlerbalazs scheidler20.47%16.25%
jorge boncomptejorge boncompte10.23%16.25%
hannes frederic sowahannes frederic sowa10.23%16.25%
Total427100.00%16100.00%

EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, __be16 sport, __be16 dport, struct udp_table *udptable) { const struct ipv6hdr *iph = ipv6_hdr(skb); struct sock *sk; sk = skb_steal_sock(skb); if (unlikely(sk)) return sk; return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), udptable, skb); }

Contributors

PersonTokensPropCommitsCommitProp
kovacs krisztiankovacs krisztian7582.42%228.57%
ian morrisian morris66.59%114.29%
alexander duyckalexander duyck55.49%114.29%
eric dumazeteric dumazet33.30%228.57%
craig gallekcraig gallek22.20%114.29%
Total91100.00%7100.00%


struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, __be16 sport, __be16 dport) { const struct ipv6hdr *iph = ipv6_hdr(skb); return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), &udp_table, skb); }

Contributors

PersonTokensPropCommitsCommitProp
tom herberttom herbert6296.88%150.00%
alexander duyckalexander duyck23.12%150.00%
Total64100.00%2100.00%

EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb); /* Must be called under rcu_read_lock(). * Does increment socket refcount. */ #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY)
struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif) { struct sock *sk; sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL); if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) sk = NULL; return sk; }

Contributors

PersonTokensPropCommitsCommitProp
balazs scheidlerbalazs scheidler4758.75%133.33%
eric dumazeteric dumazet3138.75%133.33%
craig gallekcraig gallek22.50%133.33%
Total80100.00%3100.00%

EXPORT_SYMBOL_GPL(udp6_lib_lookup); #endif /* * This should be easy, if there is something there we * return it, otherwise we block. */
int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); struct sk_buff *skb; unsigned int ulen, copied; int peeked, peeking, off; int err; int is_udplite = IS_UDPLITE(sk); bool checksum_valid = false; int is_udp4; bool slow; if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len, addr_len); if (np->rxpmtu && np->rxopt.bits.rxpmtu) return ipv6_recv_rxpmtu(sk, msg, len, addr_len); try_again: peeking = off = sk_peek_offset(sk, flags); skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), &peeked, &off, &err); if (!skb) return err; ulen = skb->len; copied = len; if (copied > ulen - off) copied = ulen - off; else if (copied < ulen) msg->msg_flags |= MSG_TRUNC; is_udp4 = (skb->protocol == htons(ETH_P_IP)); /* * If checksum is needed at all, try to do it while copying the * data. If the data is truncated, or if we only want a partial * coverage checksum (UDP-Lite), do it before the copy. */ if (copied < ulen || UDP_SKB_CB(skb)->partial_cov || peeking) { checksum_valid = !udp_lib_checksum_complete(skb); if (!checksum_valid) goto csum_copy_err; } if (checksum_valid || skb_csum_unnecessary(skb)) err = skb_copy_datagram_msg(skb, off, msg, copied); else { err = skb_copy_and_csum_datagram_msg(skb, off, msg); if (err == -EINVAL) goto csum_copy_err; } if (unlikely(err)) { trace_kfree_skb(skb, udpv6_recvmsg); if (!peeked) { atomic_inc(&sk->sk_drops); if (is_udp4) UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); else UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } skb_free_datagram_locked(sk, skb); return err; } if (!peeked) { if (is_udp4) UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); else UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); } sock_recv_ts_and_drops(msg, sk, skb); /* Copy the address. */ if (msg->msg_name) { DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); sin6->sin6_family = AF_INET6; sin6->sin6_port = udp_hdr(skb)->source; sin6->sin6_flowinfo = 0; if (is_udp4) { ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &sin6->sin6_addr); sin6->sin6_scope_id = 0; } else { sin6->sin6_addr = ipv6_hdr(skb)->saddr; sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, inet6_iif(skb)); } *addr_len = sizeof(*sin6); } if (np->rxopt.all) ip6_datagram_recv_common_ctl(sk, msg, skb); if (is_udp4) { if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); } else { if (np->rxopt.all) ip6_datagram_recv_specific_ctl(sk, msg, skb); } err = copied; if (flags & MSG_TRUNC) err = ulen; __skb_free_datagram_locked(sk, skb, peeking ? -err : err); return err; csum_copy_err: slow = lock_sock_fast(sk); if (!skb_kill_datagram(sk, skb, flags)) { if (is_udp4) { UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } else { UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } } unlock_sock_fast(sk, slow); /* starting over for a new packet, but check if we need to yield */ cond_resched(); msg->msg_flags &= ~MSG_TRUNC; goto try_again; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git21629.83%1018.52%
eric dumazeteric dumazet11616.02%712.96%
herbert xuherbert xu588.01%59.26%
wei yongjunwei yongjun547.46%23.70%
hideaki yoshifujihideaki yoshifuji506.91%23.70%
hannes frederic sowahannes frederic sowa466.35%47.41%
samanthakumarsamanthakumar425.80%11.85%
brian haleybrian haley304.14%23.70%
david s. millerdavid s. miller294.01%47.41%
pavel emelianovpavel emelianov152.07%23.70%
gerrit renkergerrit renker111.52%11.85%
samuel thibaultsamuel thibault91.24%11.85%
arnaldo carvalho de meloarnaldo carvalho de melo91.24%35.56%
hideo aokihideo aoki81.10%11.85%
xufeng zhangxufeng zhang70.97%11.85%
wang chenwang chen60.83%11.85%
steffen hurrlesteffen hurrle60.83%11.85%
linus torvaldslinus torvalds50.69%11.85%
stephen hemmingerstephen hemminger30.41%11.85%
al viroal viro10.14%11.85%
duan jiongduan jiong10.14%11.85%
neil hormanneil horman10.14%11.85%
alexey dobriyanalexey dobriyan10.14%11.85%
Total724100.00%54100.00%


void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info, struct udp_table *udptable) { struct ipv6_pinfo *np; const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; const struct in6_addr *saddr = &hdr->saddr; const struct in6_addr *daddr = &hdr->daddr; struct udphdr *uh = (struct udphdr *)(skb->data+offset); struct sock *sk; int harderr; int err; struct net *net = dev_net(skb->dev); sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, inet6_iif(skb), udptable, skb); if (!sk) { __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); return; } harderr = icmpv6_err_convert(type, code, &err); np = inet6_sk(sk); if (type == ICMPV6_PKT_TOOBIG) { if (!ip6_sk_accept_pmtu(sk)) goto out; ip6_sk_update_pmtu(skb, sk, info); if (np->pmtudisc != IPV6_PMTUDISC_DONT) harderr = 1; } if (type == NDISC_REDIRECT) { ip6_sk_redirect(skb, sk); goto out; } if (!np->recverr) { if (!harderr || sk->sk_state != TCP_ESTABLISHED) goto out; } else { ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); } sk->sk_err = err; sk->sk_error_report(sk); out: return; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12640.26%725.00%
wei wangwei wang4213.42%13.57%
david s. millerdavid s. miller3410.86%310.71%
linus torvaldslinus torvalds3310.54%13.57%
duan jiongduan jiong319.90%27.14%
hannes frederic sowahannes frederic sowa134.15%13.57%
eric dumazeteric dumazet82.56%414.29%
hideaki yoshifujihideaki yoshifuji72.24%27.14%
gerrit renkergerrit renker61.92%13.57%
pavel emelianovpavel emelianov41.28%13.57%
arnaldo carvalho de meloarnaldo carvalho de melo30.96%13.57%
craig gallekcraig gallek20.64%13.57%
brian haleybrian haley20.64%13.57%
al viroal viro10.32%13.57%
ian morrisian morris10.32%13.57%
Total313100.00%28100.00%


static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { int rc; if (!ipv6_addr_any(&sk->sk_v6_daddr)) { sock_rps_save_rxhash(sk, skb); sk_mark_napi_id(sk, skb); sk_incoming_cpu_update(sk); } rc = __sock_queue_rcv_skb(sk, skb); if (rc < 0) { int is_udplite = IS_UDPLITE(sk); /* Note that an ENOMEM error is charged twice */ if (rc == -ENOMEM) UDP6_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, is_udplite); UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); kfree_skb(skb); return -1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
benjamin lahaisebenjamin lahaise10285.00%116.67%
shawn bohrershawn bohrer97.50%116.67%
eric dumazeteric dumazet86.67%350.00%
samanthakumarsamanthakumar10.83%116.67%
Total120100.00%6100.00%


static __inline__ void udpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info) { __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); }

Contributors

PersonTokensPropCommitsCommitProp
gerrit renkergerrit renker4085.11%116.67%
eric dumazeteric dumazet24.26%116.67%
brian haleybrian haley24.26%116.67%
al viroal viro12.13%116.67%
hideaki yoshifujihideaki yoshifuji12.13%116.67%
pre-gitpre-git12.13%116.67%
Total47100.00%6100.00%

static struct static_key udpv6_encap_needed __read_mostly;
void udpv6_encap_enable(void) { if (!static_key_enabled(&udpv6_encap_needed)) static_key_slow_inc(&udpv6_encap_needed); }

Contributors

PersonTokensPropCommitsCommitProp
benjamin lahaisebenjamin lahaise22100.00%1100.00%
Total22100.00%1100.00%

EXPORT_SYMBOL(udpv6_encap_enable);
int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct udp_sock *up = udp_sk(sk); int rc; int is_udplite = IS_UDPLITE(sk); if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) goto drop; if (static_key_false(&udpv6_encap_needed) && up->encap_type) { int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); /* * This is an encapsulation socket so pass the skb to * the socket's udp_encap_rcv() hook. Otherwise, just * fall through and pass this up the UDP socket. * up->encap_rcv() returns the following value: * =0 if skb was successfully passed to the encap * handler or was discarded by it. * >0 if skb should be passed on to UDP. * <0 if skb should be resubmitted as proto -N */ /* if we're overly short, let UDP handle it */ encap_rcv = ACCESS_ONCE(up->encap_rcv); if (encap_rcv) { int ret; /* Verify checksum before giving to encap */ if (udp_lib_checksum_complete(skb)) goto csum_error; ret = encap_rcv(sk, skb); if (ret <= 0) { __UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); return -ret; } } /* FALLTHROUGH -- it's a UDP Packet */ } /* * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). */ if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov