cregit-Linux how code gets into the kernel

Release 4.11 net/ipv6/ndisc.c

Directory: net/ipv6
/*
 *      Neighbour Discovery for IPv6
 *      Linux INET6 implementation
 *
 *      Authors:
 *      Pedro Roque             <roque@di.fc.ul.pt>
 *      Mike Shaver             <shaver@ingenia.com>
 *
 *      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.
 */

/*
 *      Changes:
 *
 *      Alexey I. Froloff               :       RFC6106 (DNSSL) support
 *      Pierre Ynard                    :       export userland ND options
 *                                              through netlink (RDNSS support)
 *      Lars Fenneberg                  :       fixed MTU setting on receipt
 *                                              of an RA.
 *      Janos Farkas                    :       kmalloc failure checks
 *      Alexey Kuznetsov                :       state machine reworked
 *                                              and moved to net/core.
 *      Pekka Savola                    :       RFC2461 validation
 *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
 */


#define pr_fmt(fmt) "ICMPv6: " fmt

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/route.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif

#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/jhash.h>

#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/icmp.h>

#include <net/netlink.h>
#include <linux/rtnetlink.h>

#include <net/flow.h>
#include <net/ip6_checksum.h>
#include <net/inet_common.h>
#include <linux/proc_fs.h>

#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>

static u32 ndisc_hash(const void *pkey,
		      const struct net_device *dev,
		      __u32 *hash_rnd);
static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
static int ndisc_constructor(struct neighbour *neigh);
static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
static int pndisc_constructor(struct pneigh_entry *n);
static void pndisc_destructor(struct pneigh_entry *n);
static void pndisc_redo(struct sk_buff *skb);


static const struct neigh_ops ndisc_generic_ops = {
	.family =		AF_INET6,
	.solicit =		ndisc_solicit,
	.error_report =		ndisc_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_connected_output,
};


static const struct neigh_ops ndisc_hh_ops = {
	.family =		AF_INET6,
	.solicit =		ndisc_solicit,
	.error_report =		ndisc_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_resolve_output,
};



static const struct neigh_ops ndisc_direct_ops = {
	.family =		AF_INET6,
	.output =		neigh_direct_output,
	.connected_output =	neigh_direct_output,
};


struct neigh_table nd_tbl = {
	.family =	AF_INET6,
	.key_len =	sizeof(struct in6_addr),
	.protocol =	cpu_to_be16(ETH_P_IPV6),
	.hash =		ndisc_hash,
	.key_eq =	ndisc_key_eq,
	.constructor =	ndisc_constructor,
	.pconstructor =	pndisc_constructor,
	.pdestructor =	pndisc_destructor,
	.proxy_redo =	pndisc_redo,
	.id =		"ndisc_cache",
	.parms = {
		.tbl			= &nd_tbl,
		.reachable_time		= ND_REACHABLE_TIME,
		.data = {
			[NEIGH_VAR_MCAST_PROBES] = 3,
			[NEIGH_VAR_UCAST_PROBES] = 3,
			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
			[NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
			[NEIGH_VAR_PROXY_QLEN] = 64,
			[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
			[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
                },
        },
	.gc_interval =	  30 * HZ,
	.gc_thresh1 =	 128,
	.gc_thresh2 =	 512,
	.gc_thresh3 =	1024,
};

EXPORT_SYMBOL_GPL(nd_tbl);


void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data, int data_len, int pad) { int space = __ndisc_opt_addr_space(data_len, pad); u8 *opt = skb_put(skb, space); opt[0] = type; opt[1] = space>>3; memset(opt + 2, 0, pad); opt += pad; space -= pad; memcpy(opt+2, data, data_len); data_len += 2; opt += data_len; space -= data_len; if (space > 0) memset(opt, 0, space); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6051.28%333.33%
Roland Dreier2420.51%111.11%
Hideaki Yoshifuji / 吉藤英明1815.38%333.33%
Alexander Aring119.40%111.11%
Ian Morris43.42%111.11%
Total117100.00%9100.00%

EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data, u8 icmp6_type) { __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len, ndisc_addr_option_pad(skb->dev->type)); ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type); }

Contributors

PersonTokensPropCommitsCommitProp
Alexander Aring57100.00%2100.00%
Total57100.00%2100.00%


static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb, void *ha, const u8 *ops_data) { ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT); ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data); }

Contributors

PersonTokensPropCommitsCommitProp
Alexander Aring43100.00%2100.00%
Total43100.00%2100.00%


static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, struct nd_opt_hdr *end) { int type; if (!cur || !end || cur >= end) return NULL; type = cur->nd_opt_type; do { cur = ((void *)cur) + (cur->nd_opt_len << 3); } while (cur < end && cur->nd_opt_type != type); return cur <= end && cur->nd_opt_type == type ? cur : NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明91100.00%2100.00%
Total91100.00%2100.00%


static inline int ndisc_is_useropt(const struct net_device *dev, struct nd_opt_hdr *opt) { return opt->nd_opt_type == ND_OPT_RDNSS || opt->nd_opt_type == ND_OPT_DNSSL || ndisc_ops_is_useropt(dev, opt->nd_opt_type); }

Contributors

PersonTokensPropCommitsCommitProp
Pierre Ynard1947.50%133.33%
Alexander Aring1537.50%133.33%
Alexey I. Froloff615.00%133.33%
Total40100.00%3100.00%


static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev, struct nd_opt_hdr *cur, struct nd_opt_hdr *end) { if (!cur || !end || cur >= end) return NULL; do { cur = ((void *)cur) + (cur->nd_opt_len << 3); } while (cur < end && !ndisc_is_useropt(dev, cur)); return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Pierre Ynard8189.01%150.00%
Alexander Aring1010.99%150.00%
Total91100.00%2100.00%


struct ndisc_options *ndisc_parse_options(const struct net_device *dev, u8 *opt, int opt_len, struct ndisc_options *ndopts) { struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; if (!nd_opt || opt_len < 0 || !ndopts) return NULL; memset(ndopts, 0, sizeof(*ndopts)); while (opt_len) { int l; if (opt_len < sizeof(struct nd_opt_hdr)) return NULL; l = nd_opt->nd_opt_len << 3; if (opt_len < l || l == 0) return NULL; if (ndisc_ops_parse_options(dev, nd_opt, ndopts)) goto next_opt; switch (nd_opt->nd_opt_type) { case ND_OPT_SOURCE_LL_ADDR: case ND_OPT_TARGET_LL_ADDR: case ND_OPT_MTU: case ND_OPT_NONCE: case ND_OPT_REDIRECT_HDR: if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { ND_PRINTK(2, warn, "%s: duplicated ND6 option found: type=%d\n", __func__, nd_opt->nd_opt_type); } else { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } break; case ND_OPT_PREFIX_INFO: ndopts->nd_opts_pi_end = nd_opt; if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; break; #ifdef CONFIG_IPV6_ROUTE_INFO case ND_OPT_ROUTE_INFO: ndopts->nd_opts_ri_end = nd_opt; if (!ndopts->nd_opts_ri) ndopts->nd_opts_ri = nd_opt; break; #endif default: if (ndisc_is_useropt(dev, nd_opt)) { ndopts->nd_useropts_end = nd_opt; if (!ndopts->nd_useropts) ndopts->nd_useropts = nd_opt; } else { /* * Unknown options must be silently ignored, * to accommodate future extension to the * protocol. */ ND_PRINTK(2, notice, "%s: ignored unsupported option; type=%d, len=%d\n", __func__, nd_opt->nd_opt_type, nd_opt->nd_opt_len); } } next_opt: opt_len -= l; nd_opt = ((void *)nd_opt) + l; } return ndopts; }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明24976.85%327.27%
Pierre Ynard329.88%19.09%
Alexander Aring247.41%19.09%
Joe Perches123.70%218.18%
Erik Nordmark30.93%19.09%
Stephen Hemminger20.62%218.18%
Harvey Harrison20.62%19.09%
Total324100.00%11100.00%


int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) { switch (dev->type) { case ARPHRD_ETHER: case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ case ARPHRD_FDDI: ipv6_eth_mc_map(addr, buf); return 0; case ARPHRD_ARCNET: ipv6_arcnet_mc_map(addr, buf); return 0; case ARPHRD_INFINIBAND: ipv6_ib_mc_map(addr, dev->broadcast, buf); return 0; case ARPHRD_IPGRE: return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); default: if (dir) { memcpy(buf, dev->broadcast, dev->addr_len); return 0; } } return -EINVAL; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7863.41%550.00%
Timo Teräs1512.20%110.00%
Roland Dreier1310.57%110.00%
Hideaki Yoshifuji / 吉藤英明129.76%110.00%
Rolf Manderscheid43.25%110.00%
Eric Dumazet10.81%110.00%
Total123100.00%10100.00%

EXPORT_SYMBOL(ndisc_mc_map);
static u32 ndisc_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd) { return ndisc_hashfn(pkey, dev, hash_rnd); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1961.29%125.00%
David S. Miller929.03%250.00%
Eric Dumazet39.68%125.00%
Total31100.00%4100.00%


static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) { return neigh_key_eq128(n, pkey); }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann25100.00%1100.00%
Total25100.00%1100.00%


static int ndisc_constructor(struct neighbour *neigh) { struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; struct net_device *dev = neigh->dev; struct inet6_dev *in6_dev; struct neigh_parms *parms; bool is_multicast = ipv6_addr_is_multicast(addr); in6_dev = in6_dev_get(dev); if (!in6_dev) { return -EINVAL; } parms = in6_dev->nd_parms; __neigh_parms_put(neigh->parms); neigh->parms = neigh_parms_clone(parms); neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; if (!dev->header_ops) { neigh->nud_state = NUD_NOARP; neigh->ops = &ndisc_direct_ops; neigh->output = neigh_direct_output; } else { if (is_multicast) { neigh->nud_state = NUD_NOARP; ndisc_mc_map(addr, neigh->ha, dev, 1); } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { neigh->nud_state = NUD_NOARP; memcpy(neigh->ha, dev->dev_addr, dev->addr_len); if (dev->flags&IFF_LOOPBACK) neigh->type = RTN_LOCAL; } else if (dev->flags&IFF_POINTOPOINT) { neigh->nud_state = NUD_NOARP; memcpy(neigh->ha, dev->broadcast, dev->addr_len); } if (dev->header_ops->cache) neigh->ops = &ndisc_hh_ops; else neigh->ops = &ndisc_generic_ops; if (neigh->nud_state&NUD_VALID) neigh->output = neigh->ops->connected_output; else neigh->output = neigh->ops->output; } in6_dev_put(in6_dev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)25484.39%753.85%
Herbert Xu299.63%17.69%
Hideaki Yoshifuji / 吉藤英明103.32%17.69%
Stephen Hemminger51.66%17.69%
David S. Miller10.33%17.69%
Eric Dumazet10.33%17.69%
Ian Morris10.33%17.69%
Total301100.00%13100.00%


static int pndisc_constructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr *)&n->key; struct in6_addr maddr; struct net_device *dev = n->dev; if (!dev || !__in6_dev_get(dev)) return -EINVAL; addrconf_addr_solict_mult(addr, &maddr); ipv6_dev_mc_inc(dev, &maddr); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7095.89%675.00%
Ian Morris22.74%112.50%
Linus Torvalds11.37%112.50%
Total73100.00%8100.00%


static void pndisc_destructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr *)&n->key; struct in6_addr maddr; struct net_device *dev = n->dev; if (!dev || !__in6_dev_get(dev)) return; addrconf_addr_solict_mult(addr, &maddr); ipv6_dev_mc_dec(dev, &maddr); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6495.52%675.00%
Ian Morris22.99%112.50%
Linus Torvalds11.49%112.50%
Total67100.00%8100.00%


static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, int len) { int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; struct sk_buff *skb; skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); if (!skb) { ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", __func__); return NULL; } skb->protocol = htons(ETH_P_IPV6); skb->dev = dev; skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); skb_reset_transport_header(skb); /* Manually assign socket ownership as we avoid calling * sock_alloc_send_pskb() to bypass wmem buffer limits */ skb_set_owner_w(skb, sk); return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明12391.79%480.00%
Thomas Graf118.21%120.00%
Total134100.00%5100.00%


static void ip6_nd_hdr(struct sk_buff *skb, const struct in6_addr *saddr, const struct in6_addr *daddr, int hop_limit, int len) { struct ipv6hdr *hdr; skb_push(skb, sizeof(*hdr)); skb_reset_network_header(skb); hdr = ipv6_hdr(skb); ip6_flow_hdr(hdr, 0, 0); hdr->payload_len = htons(len); hdr->nexthdr = IPPROTO_ICMPV6; hdr->hop_limit = hop_limit; hdr->saddr = *saddr; hdr->daddr = *daddr; }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明101100.00%3100.00%
Total101100.00%3100.00%


static void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, const struct in6_addr *saddr) { struct dst_entry *dst = skb_dst(skb); struct net *net = dev_net(skb->dev); struct sock *sk = net->ipv6.ndisc_sk; struct inet6_dev *idev; int err; struct icmp6hdr *icmp6h = icmp6_hdr(skb); u8 type; type = icmp6h->icmp6_type; if (!dst) { struct flowi6 fl6; int oif = skb->dev->ifindex; icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif); dst = icmp6_dst_alloc(skb->dev, &fl6); if (IS_ERR(dst)) { kfree_skb(skb); return; } skb_dst_set(skb, dst); } icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, csum_partial(icmp6h, skb->len, 0)); ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len); rcu_read_lock(); idev = __in6_dev_get(dst->dev); IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb, NULL, dst->dev, dst_output); if (!err) { ICMP6MSGOUT_INC_STATS(net, idev, type); ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); } rcu_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明9333.57%722.58%
Brian Haley8430.32%13.23%
jlut@cs.hut.fi196.86%13.23%
Randy Dunlap134.69%13.23%
David Ahern124.33%26.45%
Linus Torvalds (pre-git)124.33%39.68%
Eric Dumazet103.61%26.45%
David S. Miller93.25%39.68%
Neil Horman62.17%13.23%
Denis V. Lunev62.17%39.68%
Eric W. Biedermann31.08%26.45%
Shirley Ma31.08%13.23%
Kazunori Miyazawa31.08%13.23%
David L Stevens20.72%13.23%
Jan Engelhardt10.36%13.23%
Patrick McHardy10.36%13.23%
Total277100.00%31100.00%


void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, const struct in6_addr *solicited_addr, bool router, bool solicited, bool override, bool inc_opt) { struct sk_buff *skb; struct in6_addr tmpaddr; struct inet6_ifaddr *ifp; const struct in6_addr *src_addr; struct nd_msg *msg; int optlen = 0; /* for anycast or proxy, solicited_addr != src_addr */ ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); if (ifp) { src_addr = solicited_addr; if (ifp->flags & IFA_F_OPTIMISTIC) override = false; inc_opt |= ifp->idev->cnf.force_tllao; in6_ifa_put(ifp); } else { if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, &tmpaddr)) return; src_addr = &tmpaddr; } if (!dev->addr_len) inc_opt = 0; if (inc_opt) optlen += ndisc_opt_addr_space(dev, NDISC_NEIGHBOUR_ADVERTISEMENT); skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); if (!skb) return; msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); *msg = (struct nd_msg) { .icmph = { .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, .icmp6_router = router, .icmp6_solicited = solicited, .icmp6_override = override, }, .target = *solicited_addr, }; if (inc_opt) ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, dev->dev_addr, NDISC_NEIGHBOUR_ADVERTISEMENT); ndisc_send_skb(skb, daddr, src_addr); }

Contributors

PersonTokensPropCommitsCommitProp
Hideaki Yoshifuji / 吉藤英明23782.58%738.89%
Linus Torvalds (pre-git)206.97%316.67%
Stephen Hemminger103.48%15.56%
Kazunori Miyazawa51.74%15.56%
Brian Haley51.74%15.56%
Alexander Aring41.39%15.56%
Randy Dunlap31.05%15.56%
Daniel Lezcano20.70%211.11%
Daniel Baluta10.35%15.56%
Total287100.00%18100.00%


static void ndisc_send_unsol_na(struct net_device *dev) { struct inet6_dev *idev; struct inet6_ifaddr *ifa; idev = in6_dev_get(dev); if (!idev) return; read_lock_bh(&idev->lock); list_for_each_entry(ifa, &idev->addr_list, if_list) { ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr, /*router=*/ !!idev->cnf.forwarding, /*solicited=*/ false, /*override=*/ true, /*inc_opt=*/ true); } read_unlock_bh(&idev->lock); in6_dev_put(idev); }

Contributors

PersonTokensPropCommitsCommitProp
Ben Hutchings9598.96%150.00%
Hideaki Yoshifuji / 吉藤英明11.04%150.00%
Total96100.00%2100.00%


void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, const struct in6_addr *daddr, const struct in6_addr *saddr, u64 nonce) { struct sk_buff *skb; struct in6_addr addr_buf; int inc_opt = dev->addr_len; int optlen = 0; struct nd_msg *msg; if (!saddr) { if (ipv6_get_lladdr(dev, &addr_buf, (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) return; saddr = &addr_buf; } if (ipv6_addr_any(saddr)) inc_opt = false; if (inc_opt) optlen += ndisc_opt_addr_space(dev, NDISC_NEIGHBOUR_SOLICITATION); if (nonce != 0) optlen += 8; skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); if (!skb) return; msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); *msg = (struct nd_msg) { .icmph = { .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, },