cregit-Linux how code gets into the kernel

Release 4.15 net/ipv4/ip_fragment.c

Directory: net/ipv4
// SPDX-License-Identifier: GPL-2.0
/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              The IP fragmentation functionality.
 *
 * Authors:     Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
 *              Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * Fixes:
 *              Alan Cox        :       Split from ip.c , see ip_input.c for history.
 *              David S. Miller :       Begin massive cleanup...
 *              Andi Kleen      :       Add sysctls.
 *              xxxx            :       Overlapfrag bug.
 *              Ultima          :       ip_expire() kernel panic.
 *              Bill Hawes      :       Frag accounting and evictor fixes.
 *              John McDonald   :       0 length frag bug.
 *              Alexey Kuznetsov:       SMP races, threading, cleanup.
 *              Patrick McHardy :       LRU queue of frag heads for evictor.
 */


#define pr_fmt(fmt) "IPv4: " fmt

#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/jiffies.h>
#include <linux/skbuff.h>
#include <linux/list.h>
#include <linux/ip.h>
#include <linux/icmp.h>
#include <linux/netdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <net/route.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/checksum.h>
#include <net/inetpeer.h>
#include <net/inet_frag.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/inet.h>
#include <linux/netfilter_ipv4.h>
#include <net/inet_ecn.h>
#include <net/l3mdev.h>

/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
 * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
 * as well. Or notify me, at least. --ANK
 */

static const char ip_frag_cache_name[] = "ip4-frags";


struct ipfrag_skb_cb
{
	
struct inet_skb_parm	h;
	
int			offset;
};


#define FRAG_CB(skb)	((struct ipfrag_skb_cb *)((skb)->cb))

/* Describe an entry in the "incomplete datagrams" queue. */

struct ipq {
	
struct inet_frag_queue q;

	
u32		user;
	
__be32		saddr;
	
__be32		daddr;
	
__be16		id;
	
u8		protocol;
	
u8		ecn; /* RFC3168 support */
	
u16		max_df_size; /* largest frag with DF set seen */
	
int             iif;
	
int             vif;   /* L3 master device index */
	
unsigned int    rid;
	
struct inet_peer *peer;
};


static u8 ip4_frag_ecn(u8 tos) { return 1 << (tos & INET_ECN_MASK); }

Contributors

PersonTokensPropCommitsCommitProp
Eric Dumazet18100.00%2100.00%
Total18100.00%2100.00%

static struct inet_frags ip4_frags;
int ip_frag_mem(struct net *net) { return sum_frag_mem_limit(&net->ipv4.frags); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov1885.71%250.00%
Patrick McHardy29.52%125.00%
Jesper Dangaard Brouer14.76%125.00%
Total21100.00%4100.00%

static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, struct net_device *dev); struct ip4_create_arg { struct iphdr *iph; u32 user; int vif; };
static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot) { net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd)); return jhash_3words((__force u32)id << 16 | prot, (__force u32)saddr, (__force u32)daddr, ip4_frags.rnd); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2132.81%233.33%
Hannes Frederic Sowa1523.44%116.67%
David S. Miller1320.31%116.67%
Al Viro1218.75%116.67%
Pavel Emelyanov34.69%116.67%
Total64100.00%6100.00%


static unsigned int ip4_hashfn(const struct inet_frag_queue *q) { const struct ipq *ipq; ipq = container_of(q, struct ipq, q); return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol); }

Contributors

PersonTokensPropCommitsCommitProp
David S. Miller2345.10%125.00%
Pavel Emelyanov2141.18%125.00%
Yasuyuki Kozakai59.80%125.00%
Florian Westphal23.92%125.00%
Total51100.00%4100.00%


static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a) { const struct ipq *qp; const struct ip4_create_arg *arg = a; qp = container_of(q, struct ipq, q); return qp->id == arg->iph->id && qp->saddr == arg->iph->saddr && qp->daddr == arg->iph->daddr && qp->protocol == arg->iph->protocol && qp->user == arg->user && qp->vif == arg->vif; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov8787.00%125.00%
David Ahern88.00%125.00%
Florian Westphal44.00%125.00%
Eric Dumazet11.00%125.00%
Total100100.00%4100.00%


static void ip4_frag_init(struct inet_frag_queue *q, const void *a) { struct ipq *qp = container_of(q, struct ipq, q); struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4, frags); struct net *net = container_of(ipv4, struct net, ipv4); const struct ip4_create_arg *arg = a; qp->protocol = arg->iph->protocol; qp->id = arg->iph->id; qp->ecn = ip4_frag_ecn(arg->iph->tos); qp->saddr = arg->iph->saddr; qp->daddr = arg->iph->daddr; qp->vif = arg->vif; qp->user = arg->user; qp->peer = q->net->max_dist ? inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, arg->vif, 1) : NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov8549.13%214.29%
Gao Feng3419.65%17.14%
Eric Dumazet137.51%17.14%
David Ahern126.94%214.29%
David S. Miller116.36%321.43%
Linus Torvalds (pre-git)105.78%214.29%
Nikolay Borisov52.89%17.14%
Florian Westphal21.16%17.14%
Linus Torvalds10.58%17.14%
Total173100.00%14100.00%


static void ip4_frag_free(struct inet_frag_queue *q) { struct ipq *qp; qp = container_of(q, struct ipq, q); if (qp->peer) inet_putpeer(qp->peer); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov3482.93%233.33%
Linus Torvalds (pre-git)512.20%350.00%
Linus Torvalds24.88%116.67%
Total41100.00%6100.00%

/* Destruction primitives. */
static void ipq_put(struct ipq *ipq) { inet_frag_put(&ipq->q, &ip4_frags); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1463.64%350.00%
Pavel Emelyanov836.36%350.00%
Total22100.00%6100.00%

/* Kill ipq entry. It is not destroyed immediately, * because caller (and someone more) holds reference count. */
static void ipq_kill(struct ipq *ipq) { inet_frag_kill(&ipq->q, &ip4_frags); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1881.82%360.00%
Pavel Emelyanov418.18%240.00%
Total22100.00%5100.00%


static bool frag_expire_skip_icmp(u32 user) { return user == IP_DEFRAG_AF_PACKET || ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN, __IP_DEFRAG_CONNTRACK_IN_END) || ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN, __IP_DEFRAG_CONNTRACK_BRIDGE_IN); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Zhou32100.00%2100.00%
Total32100.00%2100.00%

/* * Oops, a fragment queue timed out. Kill it and send an ICMP reply. */
static void ip_expire(struct timer_list *t) { struct inet_frag_queue *frag = from_timer(frag, t, timer); struct ipq *qp; struct net *net; qp = container_of(frag, struct ipq, q); net = container_of(qp->q.net, struct net, ipv4.frags); rcu_read_lock(); spin_lock(&qp->q.lock); if (qp->q.flags & INET_FRAG_COMPLETE) goto out; ipq_kill(qp); __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); if (!inet_frag_evicting(&qp->q)) { struct sk_buff *clone, *head = qp->q.fragments; const struct iphdr *iph; int err; __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT); if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !qp->q.fragments) goto out; head->dev = dev_get_by_index_rcu(net, qp->iif); if (!head->dev) goto out; /* skb has no dst, perform route lookup again */ iph = ip_hdr(head); err = ip_route_input_noref(head, iph->daddr, iph->saddr, iph->tos, head->dev); if (err) goto out; /* Only an end host needs to send an ICMP * "Fragment Reassembly Timeout" message, per RFC792. */ if (frag_expire_skip_icmp(qp->user) && (skb_rtable(head)->rt_type != RTN_LOCAL)) goto out; clone = skb_clone(head, GFP_ATOMIC); /* Send an ICMP "Fragment Reassembly Timeout" message. */ if (clone) { spin_unlock(&qp->q.lock); icmp_send(clone, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0); consume_skb(clone); goto out_rcu_unlock; } } out: spin_unlock(&qp->q.lock); out_rcu_unlock: rcu_read_unlock(); ipq_put(qp); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8727.10%723.33%
Eric Dumazet7322.74%516.67%
Shan Wei4814.95%13.33%
Pavel Emelyanov4614.33%413.33%
Nikolay Aleksandrov3611.21%310.00%
Kees Cook195.92%13.33%
Andy Zhou30.93%13.33%
David S. Miller20.62%26.67%
Vasily Averin20.62%13.33%
Joe Perches10.31%13.33%
Patrick McHardy10.31%13.33%
Hideaki Yoshifuji / 吉藤英明10.31%13.33%
Eric W. Biedermann10.31%13.33%
Denis V. Lunev10.31%13.33%
Total321100.00%30100.00%

/* Find the correct entry in the "incomplete datagrams" queue for * this IP datagram, and create new one, if nothing is found. */
static struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user, int vif) { struct inet_frag_queue *q; struct ip4_create_arg arg; unsigned int hash; arg.iph = iph; arg.user = user; arg.vif = vif; hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash); if (IS_ERR_OR_NULL(q)) { inet_frag_maybe_warn_overflow(q, pr_fmt()); return NULL; } return container_of(q, struct ipq, q); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov6752.76%440.00%
Linus Torvalds (pre-git)2318.11%220.00%
Hannes Frederic Sowa1612.60%110.00%
David Ahern97.09%110.00%
Patrick McHardy75.51%110.00%
Herbert Xu53.94%110.00%
Total127100.00%10100.00%

/* Is the fragment too far ahead to be part of ipq? */
static int ip_frag_too_far(struct ipq *qp) { struct inet_peer *peer = qp->peer; unsigned int max = qp->q.net->max_dist; unsigned int start, end; int rc; if (!peer || !max) return 0; start = qp->rid; end = atomic_inc_return(&peer->rid); qp->rid = end; rc = qp->q.fragments && (end - start) > max; if (rc) { struct net *net; net = container_of(qp->q.net, struct net, ipv4.frags); __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); } return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Herbert Xu9472.87%120.00%
Pavel Emelyanov2720.93%240.00%
Nikolay Borisov75.43%120.00%
Eric Dumazet10.78%120.00%
Total129100.00%5100.00%


static int ip_frag_reinit(struct ipq *qp) { struct sk_buff *fp; unsigned int sum_truesize = 0; if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) { refcount_inc(&qp->q.refcnt); return -ETIMEDOUT; } fp = qp->q.fragments; do { struct sk_buff *xp = fp->next; sum_truesize += fp->truesize; kfree_skb(fp); fp = xp; } while (fp); sub_frag_mem_limit(qp->q.net, sum_truesize); qp->q.flags = 0; qp->q.len = 0; qp->q.meat = 0; qp->q.fragments = NULL; qp->q.fragments_tail = NULL; qp->iif = 0; qp->ecn = 0; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Herbert Xu10562.87%19.09%
Jesper Dangaard Brouer2213.17%19.09%
Pavel Emelyanov2213.17%436.36%
Changli Gao84.79%19.09%
Eric Dumazet63.59%19.09%
Florian Westphal21.20%19.09%
Nikolay Aleksandrov10.60%19.09%
Elena Reshetova10.60%19.09%
Total167100.00%11100.00%

/* Add new segment to existing queue. */
static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) { struct sk_buff *prev, *next; struct net_device *dev; unsigned int fragsize; int flags, offset; int ihl, end; int err = -ENOENT; u8 ecn; if (qp->q.flags & INET_FRAG_COMPLETE) goto err; if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && unlikely(ip_frag_too_far(qp)) && unlikely(err = ip_frag_reinit(qp))) { ipq_kill(qp); goto err; } ecn = ip4_frag_ecn(ip_hdr(skb)->tos); offset = ntohs(ip_hdr(skb)->frag_off); flags = offset & ~IP_OFFSET; offset &= IP_OFFSET; offset <<= 3; /* offset is in 8-byte chunks */ ihl = ip_hdrlen(skb); /* Determine the position of this fragment. */ end = offset + skb->len - skb_network_offset(skb) - ihl; err = -EINVAL; /* Is this the final fragment? */ if ((flags & IP_MF) == 0) { /* If we already have some bits beyond end * or have different end, the segment is corrupted. */ if (end < qp->q.len || ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len)) goto err; qp->q.flags |= INET_FRAG_LAST_IN; qp->q.len = end; } else { if (end&7) { end &= ~7; if (skb->ip_summed != CHECKSUM_UNNECESSARY) skb->ip_summed = CHECKSUM_NONE; } if (end > qp->q.len) { /* Some bits beyond end -> corruption. */ if (qp->q.flags & INET_FRAG_LAST_IN) goto err; qp->q.len = end; } } if (end == offset) goto err; err = -ENOMEM; if (!pskb_pull(skb, skb_network_offset(skb) + ihl)) goto err; err = pskb_trim_rcsum(skb, end - offset); if (err) goto err; /* Find out which fragments are in front and at the back of us * in the chain of fragments so far. We must know where to put * this fragment, right? */ prev = qp->q.fragments_tail; if (!prev || FRAG_CB(prev)->offset < offset) { next = NULL; goto found; } prev = NULL; for (next = qp->q.fragments; next != NULL; next = next->next) { if (FRAG_CB(next)->offset >= offset) break; /* bingo! */ prev = next; } found: /* We found where to put this one. Check for overlap with * preceding fragment, and, if needed, align things so that * any overlaps are eliminated. */ if (prev) { int i = (FRAG_CB(prev)->offset + prev->len) - offset; if (i > 0) { offset += i; err = -EINVAL; if (end <= offset) goto err; err = -ENOMEM; if (!pskb_pull(skb, i)) goto err; if (skb->ip_summed != CHECKSUM_UNNECESSARY) skb->ip_summed = CHECKSUM_NONE; } } err = -ENOMEM; while (next && FRAG_CB(next)->offset < end) { int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */ if (i < next->len) { /* Eat head of the next overlapped fragment * and leave the loop. The next ones cannot overlap. */ if (!pskb_pull(next, i)) goto err; FRAG_CB(next)->offset += i; qp->q.meat -= i; if (next->ip_summed != CHECKSUM_UNNECESSARY) next->ip_summed = CHECKSUM_NONE; break; } else { struct sk_buff *free_it = next; /* Old fragment is completely overridden with * new one drop it. */ next = next->next; if (prev) prev->next = next; else qp->q.fragments = next; qp->q.meat -= free_it->len; sub_frag_mem_limit(qp->q.net, free_it->truesize); kfree_skb(free_it); } } FRAG_CB(skb)->offset = offset; /* Insert this fragment in the chain of fragments. */ skb->next = next; if (!next) qp->q.fragments_tail = skb; if (prev) prev->next = skb; else qp->q.fragments = skb; dev = skb->dev; if (dev) { qp->iif = dev->ifindex; skb->dev = NULL; } qp->q.stamp = skb->tstamp; qp->q.meat += skb->len; qp->ecn |= ecn; add_frag_mem_limit(qp->q.net, skb->truesize); if (offset == 0) qp->q.flags |= INET_FRAG_FIRST_IN; fragsize = skb->len + ihl; if (fragsize > qp->q.max_size) qp->q.max_size = fragsize; if (ip_hdr(skb)->frag_off & htons(IP_DF) && fragsize > qp->max_df_size) qp->max_df_size = fragsize; if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && qp->q.meat == qp->q.len) { unsigned long orefdst = skb->_skb_refdst; skb->_skb_refdst = 0UL; err = ip_frag_reasm(qp, prev, dev); skb->_skb_refdst = orefdst; return err; } skb_dst_drop(skb); return -EINPROGRESS; err: kfree_skb(skb); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)50154.16%1539.47%
Herbert Xu12613.62%25.26%
Eric Dumazet576.16%37.89%
Pavel Emelyanov485.19%25.26%
Changli Gao464.97%12.63%
Linus Torvalds414.43%12.63%
Florian Westphal384.11%25.26%
Patrick McHardy232.49%25.26%
Jesper Dangaard Brouer121.30%12.63%
Edward Hyunkoo Jee101.08%12.63%
Joe Perches70.76%12.63%
Arnaldo Carvalho de Melo60.65%25.26%
Nikolay Aleksandrov60.65%12.63%
Stephen Hemminger10.11%12.63%
Justin P. Mattock10.11%12.63%
Peter Zijlstra10.11%12.63%
Ian Morris10.11%12.63%
Total925100.00%38100.00%

/* Build a new IP datagram from all its fragments. */
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, struct net_device *dev) { struct net *net = container_of(qp->q.net, struct net, ipv4.frags); struct iphdr *iph; struct sk_buff *fp, *head = qp->q.fragments; int len; int ihlen; int err; u8 ecn; ipq_kill(qp); ecn = ip_frag_ecn_table[qp->ecn]; if (unlikely(ecn == 0xff)) { err = -EINVAL; goto out_fail; } /* Make the one we just received the head. */ if (prev) { head = prev->next; fp = skb_clone(head, GFP_ATOMIC); if (!fp) goto out_nomem; fp->next = head->next; if (!fp->next) qp->q.fragments_tail = fp; prev->next = fp; skb_morph(head, qp->q.fragments); head->next = qp->q.fragments->next; consume_skb(qp->q.fragments); qp->q.fragments = head; } WARN_ON(!head); WARN_ON(FRAG_CB(head)->offset != 0); /* Allocate a new buffer for the datagram. */ ihlen = ip_hdrlen(head); len = ihlen + qp->q.len; err = -E2BIG; if (len > 65535) goto out_oversize; /* Head of list must not be cloned. */ if (skb_unclone(head, GFP_ATOMIC)) goto out_nomem; /* If the first fragment is fragmented itself, we split * it to two chunks: the first with data and paged part * and the second, holding only fragments. */ if (skb_has_frag_list(head)) { struct sk_buff *clone; int i, plen = 0; clone = alloc_skb(0, GFP_ATOMIC); if (!clone) goto out_nomem; clone->next = head->next; head->next = clone; skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; skb_frag_list_init(head); for (i = 0; i < skb_shinfo(head)->nr_frags; i++) plen += skb_frag_size(&skb_shinfo(head)->frags[i]); clone->len = clone->data_len = head->data_len - plen; head->data_len -= clone->len; head->len -= clone->len; clone->csum = 0; clone->ip_summed = head->ip_summed; add_frag_mem_limit(qp->q.net, clone->truesize); } skb_shinfo(head)->frag_list = head->next; skb_push(head, head->data - skb_network_header(head)); for (fp=head->next; fp; fp = fp->next) { head->data_len += fp->len; head->len += fp->len; if (head->ip_summed != fp->ip_summed) head->ip_summed = CHECKSUM_NONE; else if (head->ip_summed == CHECKSUM_COMPLETE) head->csum = csum_add(head->csum, fp->csum); head->truesize += fp->truesize; } sub_frag_mem_limit(qp->q.net, head->truesize); head->next = NULL; head->dev = dev; head->tstamp = qp->q.stamp; IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size); iph = ip_hdr(head); iph->tot_len = htons(len); iph->tos |= ecn; /* When we set IP_DF on a refragmented skb we must also force a * call to ip_fragment to avoid forwarding a DF-skb of size s while * original sender only sent fragments of size f (where f < s). * * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest * frag seen to avoid sending tiny DF-fragments in case skb was built * from one very small df-fragment and one large non-df frag. */ if (qp->max_df_size == qp->q.max_size) { IPCB(head)->flags |= IPSKB_FRAG_PMTU; iph->frag_off = htons(IP_DF); } else { iph->frag_off = 0; } ip_send_check(iph); __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS); qp->q.fragments = NULL; qp->q.fragments_tail = NULL; return 0; out_nomem: net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp); err = -ENOMEM; goto out_fail; out_oversize: net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr); out_fail: __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)22230.45%918.75%
Linus Torvalds15521.26%12.08%
Herbert Xu9112.48%12.08%
Florian Westphal7610.43%36.25%
Eric Dumazet446.04%714.58%
Pavel Emelyanov253.43%36.25%
Changli Gao233.16%12.08%
Jorge Boncompte223.02%12.08%
Patrick McHardy212.88%24.17%
Arnaldo Carvalho de Melo91.23%36.25%
Joe Perches60.82%48.33%
Jesper Dangaard Brouer60.82%12.08%
Ian Morris60.82%12.08%
David Howells50.69%12.08%
Edward Hyunkoo Jee50.69%12.08%
Ilpo Järvinen30.41%12.08%
Hideaki Yoshifuji / 吉藤英明20.27%12.08%
David S. Miller20.27%24.17%
Heikki Orsila20.27%12.08%
David Ford10.14%12.08%
Hannes Frederic Sowa10.14%12.08%
Pravin B Shelar10.14%12.08%
Harvey Harrison10.14%12.08%
Total729100.00%48100.00%

/* Process an incoming IP datagram fragment. */
int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) { struct net_device *dev = skb->dev ? : skb_dst(skb)->dev; int vif = l3mdev_master_ifindex_rcu(dev); struct ipq *qp; __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS); skb_orphan(skb); /* Lookup (or create) queue header */ qp = ip_find(net, ip_hdr(skb), user, vif); if (qp) { int ret; spin_lock(&qp->q.lock); ret = ip_frag_queue(qp, skb); spin_unlock(&qp->q.lock); ipq_put(qp); return ret; } __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); kfree_skb(skb); return -ENOMEM; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6244.60%522.73%
David Ahern2115.11%29.09%
Pavel Emelyanov1812.95%418.18%
Herbert Xu64.32%29.09%
Eric W. Biedermann53.60%14.55%
Joe Stringer53.60%14.55%
Patrick McHardy53.60%14.55%
Ian Morris42.88%14.55%
Arnaldo Carvalho de Melo42.88%14.55%
Phil Oester42.88%14.55%
Hideaki Yoshifuji / 吉藤英明32.16%29.09%
Eric Dumazet21.44%14.55%
Total139100.00%22100.00%

EXPORT_SYMBOL(ip_defrag);
struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) { struct iphdr iph; int netoff; u32 len; if (skb->protocol != htons(ETH_P_IP)) return skb; netoff = skb_network_offset(skb); if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0) return skb; if (iph.ihl < 5 || iph.version != 4) return skb; len = ntohs(iph.tot_len); if (skb->len < netoff + len || len < (iph.ihl * 4)) return skb; if (ip_is_fragment(&iph)) { skb = skb_share_check(skb, GFP_ATOMIC); if (skb) { if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) return skb; if (pskb_trim_rcsum(skb, netoff + len)) return skb; memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); if (ip_defrag(net, skb, user)) return NULL; skb_clear_hash(skb); } } return skb; }

Contributors

PersonTokensPropCommitsCommitProp
Eric Dumazet16073.39%116.67%
Johannes Berg2913.30%116.67%
Alexander Drozdov198.72%233.33%
Eric W. Biedermann73.21%116.67%
Tom Herbert31.38%116.67%
Total218100.00%6100.00%

EXPORT_SYMBOL(ip_check_defrag); #ifdef CONFIG_SYSCTL static int zero; static struct ctl_table ip4_frags_ns_ctl_table[] = { { .procname = "ipfrag_high_thresh", .data = &init_net.ipv4.frags.high_thresh, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &init_net.ipv4.frags.low_thresh }, { .procname = "ipfrag_low_thresh", .data = &init_net.ipv4.frags.low_thresh, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &init_net.ipv4.frags.high_thresh }, { .procname = "ipfrag_time", .data = &init_net.ipv4.frags.timeout, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "ipfrag_max_dist", .data = &init_net.ipv4.frags.max_dist, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero }, { } }; /* secret interval has been deprecated */ static int ip4_frags_secret_interval_unused; static struct ctl_table ip4_frags_ctl_table[] = { { .procname = "ipfrag_secret_interval", .data = &ip4_frags_secret_interval_unused, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { } };
static int __net_init ip4_frags_ns_ctl_register(struct net *net) { struct ctl_table *table; struct ctl_table_header *hdr; table = ip4_frags_ns_ctl_table; if (!net_eq(net, &init_net)) { table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL); if (!table) goto err_alloc; table[0].data = &net->ipv4.frags.high_thresh; table[0].extra1 = &net->ipv4.frags.low_thresh; table[0].extra2 = &init_net.ipv4.frags.high_thresh; table[1].data = &net->ipv4.frags.low_thresh; table[1].extra2 = &net->ipv4.frags.high_thresh; table[2].data = &net->ipv4.frags.timeout; table[3].data = &net->ipv4.frags.max_dist; } hdr = register_net_sysctl(net, "net/ipv4", table); if (!hdr) goto err_reg; net->ipv4.frags_hdr = hdr; return 0; err_reg: if (!net_eq(net, &init_net)) kfree(table); err_alloc: return -ENOMEM; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov14865.20%545.45%
Nikolay Aleksandrov4821.15%19.09%
Nikolay Borisov167.05%19.09%
Octavian Purdila104.41%19.09%
Eric W. Biedermann20.88%19.09%
Ian Morris20.88%19.09%
Alexey Dobriyan10.44%19.09%
Total227100.00%11100.00%


static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net) { struct ctl_table *table; table = net->ipv4.frags_hdr->ctl_table_arg; unregister_net_sysctl_table(net->ipv4.frags_hdr); kfree(table); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov4097.56%266.67%
Alexey Dobriyan12.44%133.33%
Total41100.00%3100.00%


static void __init ip4_frags_ctl_register(void) { register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov1368.42%133.33%
Eric W. Biedermann526.32%133.33%
Fabian Frederick15.26%133.33%
Total19100.00%3100.00%

#else
static int ip4_frags_ns_ctl_register(struct net *net) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov14100.00%2100.00%
Total14100.00%2100.00%


static void ip4_frags_ns_ctl_unregister(struct net *net) { }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov10100.00%2100.00%
Total10100.00%2100.00%


static void __init ip4_frags_ctl_register(void) { }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov787.50%150.00%
Fabian Frederick112.50%150.00%
Total8100.00%2100.00%

#endif
static int __net_init ipv4_frags_init_net(struct net *net) { /* Fragment cache limits. * * The fragment memory accounting code, (tries to) account for * the real memory usage, by measuring both the size of frag * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue)) * and the SKB's truesize. * * A 64K fragment consumes 129736 bytes (44*2944)+200 * (1500 truesize == 2944, sizeof(struct ipq) == 200) * * We will commit 4MB at one time. Should we cross that limit * we will prune down to 3MB, making room for approx 8 big 64K * fragments 8x128k. */ net->ipv4.frags.high_thresh = 4 * 1024 * 1024; net->ipv4.frags.low_thresh = 3 * 1024 * 1024; /* * Important NOTE! Fragment queue must be destroyed before MSL expires. * RFC791 is wrong proposing to prolongate timer each fragment arrival * by TTL. */ net->ipv4.frags.timeout = IP_FRAG_TIME; net->ipv4.frags.max_dist = 64; inet_frags_init_net(&net->ipv4.frags); return ip4_frags_ns_ctl_register(net); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov6076.92%562.50%
Nikolay Borisov1012.82%112.50%
Jesper Dangaard Brouer78.97%112.50%
Alexey Dobriyan11.28%112.50%
Total78100.00%8100.00%


static void __net_exit ipv4_frags_exit_net(struct net *net) { ip4_frags_ns_ctl_unregister(net); inet_frags_exit_net(&net->ipv4.frags, &ip4_frags); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov2996.67%266.67%
Alexey Dobriyan13.33%133.33%
Total30100.00%3100.00%

static struct pernet_operations ip4_frags_ops = { .init = ipv4_frags_init_net, .exit = ipv4_frags_exit_net, };
void __init ipfrag_init(void) { ip4_frags_ctl_register(); register_pernet_subsys(&ip4_frags_ops); ip4_frags.hashfn = ip4_hashfn; ip4_frags.constructor = ip4_frag_init; ip4_frags.destructor = ip4_frag_free; ip4_frags.qsize = sizeof(struct ipq); ip4_frags.match = ip4_frag_match; ip4_frags.frag_expire = ip_expire; ip4_frags.frags_cache_name = ip_frag_cache_name; if (inet_frags_init(&ip4_frags)) panic("IP: failed to allocate ip4_frags cache\n"); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov5369.74%1178.57%
Nikolay Aleksandrov1317.11%17.14%
David S. Miller911.84%17.14%
Eric Dumazet11.32%17.14%
Total76100.00%14100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov109325.44%2415.69%
Linus Torvalds (pre-git)105324.51%2315.03%
Herbert Xu46110.73%31.96%
Eric Dumazet3939.15%149.15%
Linus Torvalds2024.70%21.31%
Nikolay Aleksandrov1443.35%53.27%
Florian Westphal1343.12%53.27%
Nikolay Borisov811.89%10.65%
Changli Gao771.79%10.65%
Patrick McHardy661.54%63.92%
David S. Miller661.54%85.23%
David Ahern601.40%31.96%
Shan Wei541.26%10.65%
Jesper Dangaard Brouer481.12%21.31%
Andy Zhou350.81%21.31%
Gao Feng340.79%10.65%
Hannes Frederic Sowa320.74%31.96%
Johannes Berg290.68%10.65%
Eric W. Biedermann220.51%53.27%
Arnaldo Carvalho de Melo220.51%42.61%
Jorge Boncompte220.51%10.65%
Joe Perches210.49%53.27%
Kees Cook190.44%10.65%
Alexander Drozdov190.44%21.31%
Edward Hyunkoo Jee150.35%10.65%
Al Viro150.35%10.65%
Ian Morris130.30%21.31%
Octavian Purdila100.23%10.65%
Hideaki Yoshifuji / 吉藤英明60.14%21.31%
Joe Stringer50.12%10.65%
Yasuyuki Kozakai50.12%10.65%
David Howells50.12%10.65%
Alexey Dobriyan40.09%10.65%
Phil Oester40.09%10.65%
Tom Herbert30.07%10.65%
Ilpo Järvinen30.07%10.65%
Tejun Heo30.07%10.65%
Vasily Averin20.05%10.65%
Heikki Orsila20.05%10.65%
Fabian Frederick20.05%10.65%
David Ford10.02%10.65%
Alan Cox10.02%10.65%
Rusty Russell10.02%10.65%
Harvey Harrison10.02%10.65%
Justin P. Mattock10.02%10.65%
Jianjun Kong10.02%10.65%
Elena Reshetova10.02%10.65%
Peter Zijlstra10.02%10.65%
Stephen Hemminger10.02%10.65%
Denis V. Lunev10.02%10.65%
Pravin B Shelar10.02%10.65%
Greg Kroah-Hartman10.02%10.65%
Total4296100.00%153100.00%
Directory: net/ipv4
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