From bda7bb46343647f68591366731295a0f3eea59ed Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Mon, 17 Jun 2013 17:49:38 -0700 Subject: gre: Allow multiple protocol listener for gre protocol. Currently there is only one user is allowed to register for gre protocol. Following patch adds de-multiplexer. So that multiple modules can listen on gre protocol e.g. kernel gre devices and ovs. Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 173 ++++++++---------------------------------------------- 1 file changed, 26 insertions(+), 147 deletions(-) (limited to 'net/ipv4/ip_gre.c') diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index a982657..19863a8 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -121,103 +121,8 @@ static int ipgre_tunnel_init(struct net_device *dev); static int ipgre_net_id __read_mostly; static int gre_tap_net_id __read_mostly; -static __sum16 check_checksum(struct sk_buff *skb) -{ - __sum16 csum = 0; - - switch (skb->ip_summed) { - case CHECKSUM_COMPLETE: - csum = csum_fold(skb->csum); - - if (!csum) - break; - /* Fall through. */ - - case CHECKSUM_NONE: - skb->csum = 0; - csum = __skb_checksum_complete(skb); - skb->ip_summed = CHECKSUM_COMPLETE; - break; - } - - return csum; -} - -static int ip_gre_calc_hlen(__be16 o_flags) -{ - int addend = 4; - - if (o_flags&TUNNEL_CSUM) - addend += 4; - if (o_flags&TUNNEL_KEY) - addend += 4; - if (o_flags&TUNNEL_SEQ) - addend += 4; - return addend; -} - -static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, - bool *csum_err, int *hdr_len) -{ - unsigned int ip_hlen = ip_hdrlen(skb); - const struct gre_base_hdr *greh; - __be32 *options; - - if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) - return -EINVAL; - - greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen); - if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) - return -EINVAL; - - tpi->flags = gre_flags_to_tnl_flags(greh->flags); - *hdr_len = ip_gre_calc_hlen(tpi->flags); - - if (!pskb_may_pull(skb, *hdr_len)) - return -EINVAL; - - greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen); - - tpi->proto = greh->protocol; - - options = (__be32 *)(greh + 1); - if (greh->flags & GRE_CSUM) { - if (check_checksum(skb)) { - *csum_err = true; - return -EINVAL; - } - options++; - } - - if (greh->flags & GRE_KEY) { - tpi->key = *options; - options++; - } else - tpi->key = 0; - - if (unlikely(greh->flags & GRE_SEQ)) { - tpi->seq = *options; - options++; - } else - tpi->seq = 0; - - /* WCCP version 1 and 2 protocol decoding. - * - Change protocol to IP - * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header - */ - if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { - tpi->proto = htons(ETH_P_IP); - if ((*(u8 *)options & 0xF0) != 0x40) { - *hdr_len += 4; - if (!pskb_may_pull(skb, *hdr_len)) - return -EINVAL; - } - } - - return 0; -} - -static void ipgre_err(struct sk_buff *skb, u32 info) +static int ipgre_err(struct sk_buff *skb, u32 info, + const struct tnl_ptk_info *tpi) { /* All the routers (except for Linux) return only @@ -239,26 +144,18 @@ static void ipgre_err(struct sk_buff *skb, u32 info) const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; struct ip_tunnel *t; - struct tnl_ptk_info tpi; - int hdr_len; - bool csum_err = false; - - if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len)) { - if (!csum_err) /* ignore csum errors. */ - return; - } switch (type) { default: case ICMP_PARAMETERPROB: - return; + return PACKET_RCVD; case ICMP_DEST_UNREACH: switch (code) { case ICMP_SR_FAILED: case ICMP_PORT_UNREACH: /* Impossible event. */ - return; + return PACKET_RCVD; default: /* All others are translated to HOST_UNREACH. rfc2003 contains "deep thoughts" about NET_UNREACH, @@ -269,79 +166,61 @@ static void ipgre_err(struct sk_buff *skb, u32 info) break; case ICMP_TIME_EXCEEDED: if (code != ICMP_EXC_TTL) - return; + return PACKET_RCVD; break; case ICMP_REDIRECT: break; } - if (tpi.proto == htons(ETH_P_TEB)) + if (tpi->proto == htons(ETH_P_TEB)) itn = net_generic(net, gre_tap_net_id); else itn = net_generic(net, ipgre_net_id); iph = (const struct iphdr *)skb->data; - t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags, - iph->daddr, iph->saddr, tpi.key); + t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, + iph->daddr, iph->saddr, tpi->key); if (t == NULL) - return; + return PACKET_REJECT; - if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { - ipv4_update_pmtu(skb, dev_net(skb->dev), info, - t->parms.link, 0, IPPROTO_GRE, 0); - return; - } - if (type == ICMP_REDIRECT) { - ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, - IPPROTO_GRE, 0); - return; - } if (t->parms.iph.daddr == 0 || ipv4_is_multicast(t->parms.iph.daddr)) - return; + return PACKET_RCVD; if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) - return; + return PACKET_RCVD; if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) t->err_count++; else t->err_count = 1; t->err_time = jiffies; + return PACKET_RCVD; } -static int ipgre_rcv(struct sk_buff *skb) +static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) { struct net *net = dev_net(skb->dev); struct ip_tunnel_net *itn; const struct iphdr *iph; struct ip_tunnel *tunnel; - struct tnl_ptk_info tpi; - int hdr_len; - bool csum_err = false; - - if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len) < 0) - goto drop; - if (tpi.proto == htons(ETH_P_TEB)) + if (tpi->proto == htons(ETH_P_TEB)) itn = net_generic(net, gre_tap_net_id); else itn = net_generic(net, ipgre_net_id); iph = ip_hdr(skb); - tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags, - iph->saddr, iph->daddr, tpi.key); + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, + iph->saddr, iph->daddr, tpi->key); if (tunnel) { - ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); - return 0; + ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error); + return PACKET_RCVD; } - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); -drop: - kfree_skb(skb); - return 0; + return PACKET_REJECT; } static struct sk_buff *handle_offloads(struct ip_tunnel *tunnel, struct sk_buff *skb) @@ -708,9 +587,10 @@ static int ipgre_tunnel_init(struct net_device *dev) return ip_tunnel_init(dev); } -static const struct gre_protocol ipgre_protocol = { - .handler = ipgre_rcv, - .err_handler = ipgre_err, +static struct gre_cisco_protocol ipgre_protocol = { + .handler = ipgre_rcv, + .err_handler = ipgre_err, + .priority = 0, }; static int __net_init ipgre_init_net(struct net *net) @@ -978,7 +858,7 @@ static int __init ipgre_init(void) if (err < 0) goto pnet_tap_faied; - err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); + err = gre_cisco_register(&ipgre_protocol); if (err < 0) { pr_info("%s: can't add protocol\n", __func__); goto add_proto_failed; @@ -997,7 +877,7 @@ static int __init ipgre_init(void) tap_ops_failed: rtnl_link_unregister(&ipgre_link_ops); rtnl_link_failed: - gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); + gre_cisco_unregister(&ipgre_protocol); add_proto_failed: unregister_pernet_device(&ipgre_tap_net_ops); pnet_tap_faied: @@ -1009,8 +889,7 @@ static void __exit ipgre_fini(void) { rtnl_link_unregister(&ipgre_tap_ops); rtnl_link_unregister(&ipgre_link_ops); - if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) - pr_info("%s: can't remove protocol\n", __func__); + gre_cisco_unregister(&ipgre_protocol); unregister_pernet_device(&ipgre_tap_net_ops); unregister_pernet_device(&ipgre_net_ops); } -- cgit v1.1