nf_conntrack_proto_udp.rar_Only

/* (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2004 Netfilter Core Team <[email protected]> * (C) 2006-2012 Patrick McHardy <[email protected]> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/types.h> #include <linux/timer.h> #include <linux/module.h> #include <linux/udp.h> #include <linux/seq_file.h> #include <linux/skbuff.h> #include <linux/ipv6.h> #include <net/ip6_checksum.h> #include <net/checksum.h> #include <linux/netfilter.h> #include <linux/netfilter_ipv4.h> #include <linux/netfilter_ipv6.h> #include <net/netfilter/nf_conntrack_l4proto.h> #include <net/netfilter/nf_conntrack_ecache.h> #include <net/netfilter/nf_log.h> #include <net/netfilter/ipv4/nf_conntrack_ipv4.h> #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> static unsigned int udp_timeouts[UDP_CT_MAX] = { [UDP_CT_UNREPLIED] = 30*HZ, [UDP_CT_REPLIED] = 180*HZ, }; static inline struct nf_udp_net *udp_pernet(struct net *net) { return &net->ct.nf_ct_proto.udp; } static bool udp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff, struct nf_conntrack_tuple *tuple) { const struct udphdr *hp; struct udphdr _hdr; /* Actually only need first 8 bytes. */ hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); if (hp == NULL) return false; tuple->src.u.udp.port = hp->source; tuple->dst.u.udp.port = hp->dest; return true; } static bool udp_invert_tuple(struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *orig) { tuple->src.u.udp.port = orig->dst.u.udp.port; tuple->dst.u.udp.port = orig->src.u.udp.port; return true; } /* Print out the per-protocol part of the tuple. */ static void udp_print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple) { seq_printf(s, "sport=%hu dport=%hu ", ntohs(tuple->src.u.udp.port), ntohs(tuple->dst.u.udp.port)); } static unsigned int *udp_get_timeouts(struct net *net) { return udp_pernet(net)->timeouts; } /* Returns verdict for packet, and may modify conntracktype */ static int udp_packet(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff, enum ip_conntrack_info ctinfo, u_int8_t pf, unsigned int hooknum, unsigned int *timeouts) { /* If we've seen traffic both ways, this is some kind of UDP stream. Extend timeout. */ if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[UDP_CT_REPLIED]); /* Also, more likely to be important, and not a probe */ if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) nf_conntrack_event_cache(IPCT_ASSURED, ct); } else { nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[UDP_CT_UNREPLIED]); } return NF_ACCEPT; } /* Called when a new connection for this protocol found. */ static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff, unsigned int *timeouts) { return true; } static int udp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, unsigned int dataoff, enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum) { unsigned int udplen = skb->len - dataoff; const struct udphdr *hdr; struct udphdr _hdr; /* Header is too small? */ hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); if (hdr == NULL) { if (LOG_INVALID(net, IPPROTO_UDP)) nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "nf_ct_udp: short packet "); return -NF_ACCEPT; } /* Truncated/malformed packets */ if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) { if (LOG_INVALID(net, IPPROTO_UDP)) nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "nf_ct_udp: truncated/malformed packet "); return -NF_ACCEPT; } /* Packet with no checksum */ if (!hdr->check) return NF_ACCEPT; /* Checksum invalid? Ignore. * We skip checking packets on the outgoing path * because the checksum is assumed to be correct. * FIXME: Source route IP option packets --RR */ if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) { if (LOG_INVALID(net, IPPROTO_UDP)) nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "nf_ct_udp: bad UDP checksum "); return -NF_ACCEPT; } return NF_ACCEPT; } #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) #include <linux/netfilter/nfnetlink.h> #include <linux/netfilter/nfnetlink_cttimeout.h> static int udp_timeout_nlattr_to_obj(struct nlattr *tb[], struct net *net, void *data) { unsigned int *timeouts = data; struct nf_udp_net *un = udp_pernet(net); /* set default timeouts for UDP. */ timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED]; timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED]; if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) { timeouts[UDP_CT_UNREPLIED] = ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ; } if (tb[CTA_TIMEOUT_UDP_REPLIED]) { timeouts[UDP_CT_REPLIED] = ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ; } return 0; } static int udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) { const unsigned int *timeouts = data; if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED, htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) || nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED, htonl(timeouts[UDP_CT_REPLIED] / HZ))) goto nla_put_failure; return 0; nla_put_failure: return -ENOSPC; } static const struct nla_policy udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = { [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 }, [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 }, }; #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ #ifdef CONFIG_SYSCTL static struct ctl_table udp_sysctl_table[] = { { .procname = "nf_conntrack_udp_timeout", .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "nf_conntrack_udp_timeout_stream", .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { } }; #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT static struct ctl_table udp_compat_sysctl_table[] = { { .procname = "ip_conntrack_udp_timeout", .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "ip_conntrack_udp_timeout_stream", .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { } }; #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ #endif /* CONFIG_SYSCTL */ static int udp_kmemdup_sysctl_table(struct nf_proto_net *pn, struct nf_udp_net *un) { #ifdef CONFIG_SYSCTL if (pn->ctl_table) return 0; pn->ctl_table = kmemdup(udp_sysctl_table, sizeof(udp_sysctl_table), GFP_KERNEL); if (!pn->ctl_table) return -ENOMEM; pn->ctl_table[0].data = &un->timeouts[UDP_CT_UNREPLIED]; pn->ctl_table[1].data = &un->timeouts[UDP_CT_REPLIED]; #endif return 0; } static int udp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn, struct nf_udp_net *un) { #ifdef CONFIG_SYSCTL #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT pn->ctl_compat_table = kmemdup(udp_compat_sysctl_table, sizeof(udp_compat_sysctl_table), GFP_KERNEL); if (!pn->ctl_compat_table) return -ENOMEM; pn->ctl_compat_table[0].data = &un->timeouts[UDP_CT_UNREPLIED]; pn->ctl_compat_table[1].data = &un->timeouts[UDP_CT_REPLIED]; #endif #endif return 0; } static int udp_init_net(struct net *net, u_int16_t proto) { int ret; struct nf_udp_net *un = udp_pernet(net); struct nf_proto_net *pn = &un->pn; if (!pn->users) { int i; for (i = 0; i < UDP_CT_MAX; i++) un->timeouts[i] = udp_timeouts[i]; } if (proto == AF_INET) { ret = udp_kmemdup_compat_sysctl_table(pn, un); if (ret < 0) return ret; ret = udp_kmemdup_sysctl_table(pn, un); if (ret < 0) nf_ct_kfree_compat_sysctl_table(pn); } else ret =