^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * INET An implementation of the TCP/IP protocol suite for the LINUX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * operating system. INET is implemented using the BSD Socket
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * interface as the means of communication with the user level.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * The IP fragmentation functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Alan Cox <alan@lxorguk.ukuu.org.uk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * Fixes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * Alan Cox : Split from ip.c , see ip_input.c for history.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * David S. Miller : Begin massive cleanup...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Andi Kleen : Add sysctls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * xxxx : Overlapfrag bug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Ultima : ip_expire() kernel panic.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Bill Hawes : Frag accounting and evictor fixes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * John McDonald : 0 length frag bug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Alexey Kuznetsov: SMP races, threading, cleanup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * Patrick McHardy : LRU queue of frag heads for evictor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #define pr_fmt(fmt) "IPv4: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/compiler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/icmp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/netdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/jhash.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <net/route.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <net/dst.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <net/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <net/icmp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <net/checksum.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <net/inetpeer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <net/inet_frag.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <linux/tcp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/udp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/netfilter_ipv4.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <net/inet_ecn.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <net/l3mdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * as well. Or notify me, at least. --ANK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) static const char ip_frag_cache_name[] = "ip4-frags";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /* Describe an entry in the "incomplete datagrams" queue. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct ipq {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) struct inet_frag_queue q;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) u8 ecn; /* RFC3168 support */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) u16 max_df_size; /* largest frag with DF set seen */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) int iif;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) unsigned int rid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) struct inet_peer *peer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) static u8 ip4_frag_ecn(u8 tos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) return 1 << (tos & INET_ECN_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) static struct inet_frags ip4_frags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) struct sk_buff *prev_tail, struct net_device *dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) struct ipq *qp = container_of(q, struct ipq, q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) struct net *net = q->fqdir->net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) const struct frag_v4_compare_key *key = a;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) q->key.v4 = *key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) qp->ecn = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) qp->peer = q->fqdir->max_dist ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) static void ip4_frag_free(struct inet_frag_queue *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) struct ipq *qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) qp = container_of(q, struct ipq, q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (qp->peer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) inet_putpeer(qp->peer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) /* Destruction primitives. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static void ipq_put(struct ipq *ipq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) inet_frag_put(&ipq->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /* Kill ipq entry. It is not destroyed immediately,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * because caller (and someone more) holds reference count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) static void ipq_kill(struct ipq *ipq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) inet_frag_kill(&ipq->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static bool frag_expire_skip_icmp(u32 user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return user == IP_DEFRAG_AF_PACKET ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) __IP_DEFRAG_CONNTRACK_IN_END) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) __IP_DEFRAG_CONNTRACK_BRIDGE_IN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * Oops, a fragment queue timed out. Kill it and send an ICMP reply.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) static void ip_expire(struct timer_list *t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct inet_frag_queue *frag = from_timer(frag, t, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) const struct iphdr *iph;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) struct sk_buff *head = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) struct net *net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) struct ipq *qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) qp = container_of(frag, struct ipq, q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) net = qp->q.fqdir->net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /* Paired with WRITE_ONCE() in fqdir_pre_exit(). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) if (READ_ONCE(qp->q.fqdir->dead))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) goto out_rcu_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) spin_lock(&qp->q.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) if (qp->q.flags & INET_FRAG_COMPLETE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) ipq_kill(qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) if (!(qp->q.flags & INET_FRAG_FIRST_IN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /* sk_buff::dev and sk_buff::rbnode are unionized. So we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * pull the head out of the tree in order to be able to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * deal with head->dev.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) head = inet_frag_pull_head(&qp->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) if (!head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) head->dev = dev_get_by_index_rcu(net, qp->iif);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (!head->dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) /* skb has no dst, perform route lookup again */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) iph = ip_hdr(head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) err = ip_route_input_noref(head, iph->daddr, iph->saddr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) iph->tos, head->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) /* Only an end host needs to send an ICMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) * "Fragment Reassembly Timeout" message, per RFC792.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (frag_expire_skip_icmp(qp->q.key.v4.user) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) (skb_rtable(head)->rt_type != RTN_LOCAL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) spin_unlock(&qp->q.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) goto out_rcu_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) spin_unlock(&qp->q.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) out_rcu_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) kfree_skb(head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) ipq_put(qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) /* Find the correct entry in the "incomplete datagrams" queue for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) * this IP datagram, and create new one, if nothing is found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static struct ipq *ip_find(struct net *net, struct iphdr *iph,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) u32 user, int vif)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) struct frag_v4_compare_key key = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) .saddr = iph->saddr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) .daddr = iph->daddr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) .user = user,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) .vif = vif,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) .id = iph->id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) .protocol = iph->protocol,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) struct inet_frag_queue *q;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) q = inet_frag_find(net->ipv4.fqdir, &key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) if (!q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) return container_of(q, struct ipq, q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) /* Is the fragment too far ahead to be part of ipq? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) static int ip_frag_too_far(struct ipq *qp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) struct inet_peer *peer = qp->peer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) unsigned int max = qp->q.fqdir->max_dist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) unsigned int start, end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) int rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) if (!peer || !max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) start = qp->rid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) end = atomic_inc_return(&peer->rid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) qp->rid = end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) rc = qp->q.fragments_tail && (end - start) > max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) if (rc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) __IP_INC_STATS(qp->q.fqdir->net, IPSTATS_MIB_REASMFAILS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) static int ip_frag_reinit(struct ipq *qp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) unsigned int sum_truesize = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (!mod_timer(&qp->q.timer, jiffies + qp->q.fqdir->timeout)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) refcount_inc(&qp->q.refcnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) return -ETIMEDOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) sub_frag_mem_limit(qp->q.fqdir, sum_truesize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) qp->q.flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) qp->q.len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) qp->q.meat = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) qp->q.rb_fragments = RB_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) qp->q.fragments_tail = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) qp->q.last_run_head = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) qp->iif = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) qp->ecn = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /* Add new segment to existing queue. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) struct net *net = qp->q.fqdir->net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) int ihl, end, flags, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) struct sk_buff *prev_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) struct net_device *dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) unsigned int fragsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) int err = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) u8 ecn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) if (qp->q.flags & INET_FRAG_COMPLETE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) unlikely(ip_frag_too_far(qp)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) unlikely(err = ip_frag_reinit(qp))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) ipq_kill(qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) offset = ntohs(ip_hdr(skb)->frag_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) flags = offset & ~IP_OFFSET;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) offset &= IP_OFFSET;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) offset <<= 3; /* offset is in 8-byte chunks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) ihl = ip_hdrlen(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) /* Determine the position of this fragment. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) end = offset + skb->len - skb_network_offset(skb) - ihl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) /* Is this the final fragment? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if ((flags & IP_MF) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) /* If we already have some bits beyond end
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * or have different end, the segment is corrupted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) if (end < qp->q.len ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) goto discard_qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) qp->q.flags |= INET_FRAG_LAST_IN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) qp->q.len = end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) if (end&7) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) end &= ~7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) if (skb->ip_summed != CHECKSUM_UNNECESSARY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) skb->ip_summed = CHECKSUM_NONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) if (end > qp->q.len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) /* Some bits beyond end -> corruption. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) if (qp->q.flags & INET_FRAG_LAST_IN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) goto discard_qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) qp->q.len = end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (end == offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) goto discard_qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) goto discard_qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) err = pskb_trim_rcsum(skb, end - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) goto discard_qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) /* Note : skb->rbnode and skb->dev share the same location. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) dev = skb->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) /* Makes sure compiler wont do silly aliasing games */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) barrier();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) prev_tail = qp->q.fragments_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) err = inet_frag_queue_insert(&qp->q, skb, offset, end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) goto insert_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) if (dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) qp->iif = dev->ifindex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) qp->q.stamp = skb->tstamp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) qp->q.meat += skb->len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) qp->ecn |= ecn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) add_frag_mem_limit(qp->q.fqdir, skb->truesize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) if (offset == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) qp->q.flags |= INET_FRAG_FIRST_IN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) fragsize = skb->len + ihl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if (fragsize > qp->q.max_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) qp->q.max_size = fragsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) fragsize > qp->max_df_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) qp->max_df_size = fragsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) qp->q.meat == qp->q.len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) unsigned long orefdst = skb->_skb_refdst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) skb->_skb_refdst = 0UL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) err = ip_frag_reasm(qp, skb, prev_tail, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) skb->_skb_refdst = orefdst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) inet_frag_kill(&qp->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) skb_dst_drop(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) return -EINPROGRESS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) insert_error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) if (err == IPFRAG_DUP) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) discard_qp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) inet_frag_kill(&qp->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) static bool ip_frag_coalesce_ok(const struct ipq *qp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) return qp->q.key.v4.user == IP_DEFRAG_LOCAL_DELIVER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) /* Build a new IP datagram from all its fragments. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) struct sk_buff *prev_tail, struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) struct net *net = qp->q.fqdir->net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) struct iphdr *iph;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) void *reasm_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) int len, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) u8 ecn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) ipq_kill(qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) ecn = ip_frag_ecn_table[qp->ecn];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) if (unlikely(ecn == 0xff)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) /* Make the one we just received the head. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) reasm_data = inet_frag_reasm_prepare(&qp->q, skb, prev_tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) if (!reasm_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) goto out_nomem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) len = ip_hdrlen(skb) + qp->q.len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) err = -E2BIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) if (len > 65535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) goto out_oversize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) inet_frag_reasm_finish(&qp->q, skb, reasm_data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) ip_frag_coalesce_ok(qp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) skb->dev = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) iph = ip_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) iph->tot_len = htons(len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) iph->tos |= ecn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) /* When we set IP_DF on a refragmented skb we must also force a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * call to ip_fragment to avoid forwarding a DF-skb of size s while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * original sender only sent fragments of size f (where f < s).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * frag seen to avoid sending tiny DF-fragments in case skb was built
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * from one very small df-fragment and one large non-df frag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) if (qp->max_df_size == qp->q.max_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) IPCB(skb)->flags |= IPSKB_FRAG_PMTU;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) iph->frag_off = htons(IP_DF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) iph->frag_off = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) ip_send_check(iph);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) qp->q.rb_fragments = RB_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) qp->q.fragments_tail = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) qp->q.last_run_head = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) out_nomem:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) out_oversize:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) out_fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) /* Process an incoming IP datagram fragment. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) int vif = l3mdev_master_ifindex_rcu(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) struct ipq *qp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) skb_orphan(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) /* Lookup (or create) queue header */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) qp = ip_find(net, ip_hdr(skb), user, vif);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) if (qp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) spin_lock(&qp->q.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) ret = ip_frag_queue(qp, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) spin_unlock(&qp->q.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) ipq_put(qp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) EXPORT_SYMBOL(ip_defrag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) struct iphdr iph;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) int netoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) u32 len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) if (skb->protocol != htons(ETH_P_IP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) netoff = skb_network_offset(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (iph.ihl < 5 || iph.version != 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) len = ntohs(iph.tot_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (skb->len < netoff + len || len < (iph.ihl * 4))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) if (ip_is_fragment(&iph)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) skb = skb_share_check(skb, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) if (skb) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) if (pskb_trim_rcsum(skb, netoff + len)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) if (ip_defrag(net, skb, user))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) skb_clear_hash(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) EXPORT_SYMBOL(ip_check_defrag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) #ifdef CONFIG_SYSCTL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) static int dist_min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) static struct ctl_table ip4_frags_ns_ctl_table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) .procname = "ipfrag_high_thresh",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) .maxlen = sizeof(unsigned long),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) .mode = 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) .proc_handler = proc_doulongvec_minmax,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) .procname = "ipfrag_low_thresh",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) .maxlen = sizeof(unsigned long),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) .mode = 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) .proc_handler = proc_doulongvec_minmax,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) .procname = "ipfrag_time",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) .maxlen = sizeof(int),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) .mode = 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) .proc_handler = proc_dointvec_jiffies,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) .procname = "ipfrag_max_dist",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) .maxlen = sizeof(int),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) .mode = 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) .proc_handler = proc_dointvec_minmax,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) .extra1 = &dist_min,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) /* secret interval has been deprecated */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) static int ip4_frags_secret_interval_unused;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) static struct ctl_table ip4_frags_ctl_table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) .procname = "ipfrag_secret_interval",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) .data = &ip4_frags_secret_interval_unused,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) .maxlen = sizeof(int),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) .mode = 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) .proc_handler = proc_dointvec_jiffies,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) static int __net_init ip4_frags_ns_ctl_register(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) struct ctl_table *table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) struct ctl_table_header *hdr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) table = ip4_frags_ns_ctl_table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) if (!net_eq(net, &init_net)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) if (!table)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) goto err_alloc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) table[0].data = &net->ipv4.fqdir->high_thresh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) table[0].extra1 = &net->ipv4.fqdir->low_thresh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) table[1].data = &net->ipv4.fqdir->low_thresh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) table[1].extra2 = &net->ipv4.fqdir->high_thresh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) table[2].data = &net->ipv4.fqdir->timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) table[3].data = &net->ipv4.fqdir->max_dist;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) hdr = register_net_sysctl(net, "net/ipv4", table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (!hdr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) goto err_reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) net->ipv4.frags_hdr = hdr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) err_reg:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) if (!net_eq(net, &init_net))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) kfree(table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) err_alloc:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) struct ctl_table *table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) table = net->ipv4.frags_hdr->ctl_table_arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) unregister_net_sysctl_table(net->ipv4.frags_hdr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) kfree(table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) static void __init ip4_frags_ctl_register(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) static int ip4_frags_ns_ctl_register(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) static void ip4_frags_ns_ctl_unregister(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) static void __init ip4_frags_ctl_register(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) static int __net_init ipv4_frags_init_net(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) int res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) res = fqdir_init(&net->ipv4.fqdir, &ip4_frags, net);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) if (res < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) /* Fragment cache limits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) * The fragment memory accounting code, (tries to) account for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * the real memory usage, by measuring both the size of frag
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * and the SKB's truesize.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) * A 64K fragment consumes 129736 bytes (44*2944)+200
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) * (1500 truesize == 2944, sizeof(struct ipq) == 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) * We will commit 4MB at one time. Should we cross that limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) * we will prune down to 3MB, making room for approx 8 big 64K
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) * fragments 8x128k.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) net->ipv4.fqdir->high_thresh = 4 * 1024 * 1024;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) net->ipv4.fqdir->low_thresh = 3 * 1024 * 1024;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) * Important NOTE! Fragment queue must be destroyed before MSL expires.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) * RFC791 is wrong proposing to prolongate timer each fragment arrival
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) * by TTL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) net->ipv4.fqdir->timeout = IP_FRAG_TIME;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) net->ipv4.fqdir->max_dist = 64;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) res = ip4_frags_ns_ctl_register(net);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) if (res < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) fqdir_exit(net->ipv4.fqdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) static void __net_exit ipv4_frags_pre_exit_net(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) fqdir_pre_exit(net->ipv4.fqdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) static void __net_exit ipv4_frags_exit_net(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) ip4_frags_ns_ctl_unregister(net);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) fqdir_exit(net->ipv4.fqdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) static struct pernet_operations ip4_frags_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) .init = ipv4_frags_init_net,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) .pre_exit = ipv4_frags_pre_exit_net,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) .exit = ipv4_frags_exit_net,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) return jhash2(data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) const struct inet_frag_queue *fq = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) return jhash2((const u32 *)&fq->key.v4,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) const struct frag_v4_compare_key *key = arg->key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) const struct inet_frag_queue *fq = ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) return !!memcmp(&fq->key, key, sizeof(*key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) static const struct rhashtable_params ip4_rhash_params = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) .head_offset = offsetof(struct inet_frag_queue, node),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) .key_offset = offsetof(struct inet_frag_queue, key),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) .key_len = sizeof(struct frag_v4_compare_key),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) .hashfn = ip4_key_hashfn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) .obj_hashfn = ip4_obj_hashfn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) .obj_cmpfn = ip4_obj_cmpfn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) .automatic_shrinking = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) void __init ipfrag_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) ip4_frags.constructor = ip4_frag_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) ip4_frags.destructor = ip4_frag_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) ip4_frags.qsize = sizeof(struct ipq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) ip4_frags.frag_expire = ip_expire;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) ip4_frags.frags_cache_name = ip_frag_cache_name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) ip4_frags.rhash_params = ip4_rhash_params;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) if (inet_frags_init(&ip4_frags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) panic("IP: failed to allocate ip4_frags cache\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) ip4_frags_ctl_register();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) register_pernet_subsys(&ip4_frags_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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