X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Fxfrm4_input.c;h=2fa108245413d38bd7c88fac7c71e570e98e40b9;hb=a9417357cff6027f9d6b1740f821baa59f2381f4;hp=78e80deb7e89a25780d74a7e1691b73bb7e06b53;hpb=5a84d159061d914c8dd4aa372ac6e9529c2be453;p=linux-2.6 diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c index 78e80deb7e..2fa1082454 100644 --- a/net/ipv4/xfrm4_input.c +++ b/net/ipv4/xfrm4_input.c @@ -16,19 +16,12 @@ #include #include -int xfrm4_rcv(struct sk_buff *skb) -{ - return xfrm4_rcv_encap(skb, 0); -} - -EXPORT_SYMBOL(xfrm4_rcv); - static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq) { switch (nexthdr) { case IPPROTO_IPIP: case IPPROTO_IPV6: - *spi = skb->nh.iph->saddr; + *spi = ip_hdr(skb)->saddr; *seq = 0; return 0; } @@ -39,9 +32,9 @@ static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 #ifdef CONFIG_NETFILTER static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb) { - struct iphdr *iph = skb->nh.iph; - if (skb->dst == NULL) { + const struct iphdr *iph = ip_hdr(skb); + if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, skb->dev)) goto drop; @@ -53,20 +46,20 @@ drop: } #endif -int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) +static int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) { - int err; __be32 spi, seq; struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH]; struct xfrm_state *x; int xfrm_nr = 0; int decaps = 0; + int err = xfrm4_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq); - if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0) + if (err != 0) goto drop; do { - struct iphdr *iph = skb->nh.iph; + const struct iphdr *iph = ip_hdr(skb); if (xfrm_nr == XFRM_MAX_DEPTH) goto drop; @@ -113,7 +106,8 @@ int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) break; } - if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) < 0) + err = xfrm_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq); + if (err < 0) goto drop; } while (!err); @@ -138,23 +132,21 @@ int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) nf_reset(skb); if (decaps) { - if (!(skb->dev->flags&IFF_LOOPBACK)) { - dst_release(skb->dst); - skb->dst = NULL; - } + dst_release(skb->dst); + skb->dst = NULL; netif_rx(skb); return 0; } else { #ifdef CONFIG_NETFILTER - __skb_push(skb, skb->data - skb->nh.raw); - skb->nh.iph->tot_len = htons(skb->len); - ip_send_check(skb->nh.iph); + __skb_push(skb, skb->data - skb_network_header(skb)); + ip_hdr(skb)->tot_len = htons(skb->len); + ip_send_check(ip_hdr(skb)); NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL, xfrm4_rcv_encap_finish); return 0; #else - return -skb->nh.iph->protocol; + return -ip_hdr(skb)->protocol; #endif } @@ -168,3 +160,108 @@ drop: kfree_skb(skb); return 0; } + +/* If it's a keepalive packet, then just eat it. + * If it's an encapsulated packet, then pass it to the + * IPsec xfrm input. + * Returns 0 if skb passed to xfrm or was dropped. + * Returns >0 if skb should be passed to UDP. + * Returns <0 if skb should be resubmitted (-ret is protocol) + */ +int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct udp_sock *up = udp_sk(sk); + struct udphdr *uh; + struct iphdr *iph; + int iphlen, len; + int ret; + + __u8 *udpdata; + __be32 *udpdata32; + __u16 encap_type = up->encap_type; + + /* if this is not encapsulated socket, then just return now */ + if (!encap_type) + return 1; + + /* If this is a paged skb, make sure we pull up + * whatever data we need to look at. */ + len = skb->len - sizeof(struct udphdr); + if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8))) + return 1; + + /* Now we can get the pointers */ + uh = udp_hdr(skb); + udpdata = (__u8 *)uh + sizeof(struct udphdr); + udpdata32 = (__be32 *)udpdata; + + switch (encap_type) { + default: + case UDP_ENCAP_ESPINUDP: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + goto drop; + } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) { + /* ESP Packet without Non-ESP header */ + len = sizeof(struct udphdr); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + case UDP_ENCAP_ESPINUDP_NON_IKE: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + goto drop; + } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && + udpdata32[0] == 0 && udpdata32[1] == 0) { + + /* ESP Packet with Non-IKE marker */ + len = sizeof(struct udphdr) + 2 * sizeof(u32); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + } + + /* At this point we are sure that this is an ESPinUDP packet, + * so we need to remove 'len' bytes from the packet (the UDP + * header and optional ESP marker bytes) and then modify the + * protocol to ESP, and then call into the transform receiver. + */ + if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + goto drop; + + /* Now we can update and verify the packet length... */ + iph = ip_hdr(skb); + iphlen = iph->ihl << 2; + iph->tot_len = htons(ntohs(iph->tot_len) - len); + if (skb->len < iphlen + len) { + /* packet is too small!?! */ + goto drop; + } + + /* pull the data buffer up to the ESP header and set the + * transport header to point to ESP. Keep UDP on the stack + * for later. + */ + __skb_pull(skb, len); + skb_reset_transport_header(skb); + + /* modify the protocol (it's ESP!) */ + iph->protocol = IPPROTO_ESP; + + /* process ESP */ + ret = xfrm4_rcv_encap(skb, encap_type); + return ret; + +drop: + kfree_skb(skb); + return 0; +} + +int xfrm4_rcv(struct sk_buff *skb) +{ + return xfrm4_rcv_encap(skb, 0); +} + +EXPORT_SYMBOL(xfrm4_rcv);