From: Daniel Borkmann Date: Mon, 1 Jul 2013 17:24:00 +0000 (+0200) Subject: net: gre: move GSO functions to gre_offload X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=c50cd357887acf9fd7af3a5d492911bd825555a2;p=deliverable%2Flinux.git net: gre: move GSO functions to gre_offload Similarly to TCP/UDP offloading, move all related GRE functions to gre_offload.c to make things more explicit and similar to the rest of the code. Suggested-by: Eric Dumazet Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- diff --git a/include/net/gre.h b/include/net/gre.h index a5a4ddf05300..57e4afdf7879 100644 --- a/include/net/gre.h +++ b/include/net/gre.h @@ -32,6 +32,10 @@ struct gre_cisco_protocol { int gre_cisco_register(struct gre_cisco_protocol *proto); int gre_cisco_unregister(struct gre_cisco_protocol *proto); + +int gre_offload_init(void); +void gre_offload_exit(void); + void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi, int hdr_len); struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum); diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index 86ded0bac9c7..4b81e91c80fe 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o obj-$(CONFIG_IP_MROUTE) += ipmr.o obj-$(CONFIG_NET_IPIP) += ipip.o +gre-y := gre_demux.o gre_offload.o obj-$(CONFIG_NET_IPGRE_DEMUX) += gre.o obj-$(CONFIG_NET_IPGRE) += ip_gre.o obj-$(CONFIG_NET_IPVTI) += ip_vti.o diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c deleted file mode 100644 index ba4803e609b5..000000000000 --- a/net/ipv4/gre.c +++ /dev/null @@ -1,514 +0,0 @@ -/* - * GRE over IPv4 demultiplexer driver - * - * Authors: Dmitry Kozlov (xeb@mail.ru) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly; -static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX]; - -int gre_add_protocol(const struct gre_protocol *proto, u8 version) -{ - if (version >= GREPROTO_MAX) - return -EINVAL; - - return (cmpxchg((const struct gre_protocol **)&gre_proto[version], NULL, proto) == NULL) ? - 0 : -EBUSY; -} -EXPORT_SYMBOL_GPL(gre_add_protocol); - -int gre_del_protocol(const struct gre_protocol *proto, u8 version) -{ - int ret; - - if (version >= GREPROTO_MAX) - return -EINVAL; - - ret = (cmpxchg((const struct gre_protocol **)&gre_proto[version], proto, NULL) == proto) ? - 0 : -EBUSY; - - if (ret) - return ret; - - synchronize_rcu(); - return 0; -} -EXPORT_SYMBOL_GPL(gre_del_protocol); - -void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi, - int hdr_len) -{ - struct gre_base_hdr *greh; - - skb_push(skb, hdr_len); - - greh = (struct gre_base_hdr *)skb->data; - greh->flags = tnl_flags_to_gre_flags(tpi->flags); - greh->protocol = tpi->proto; - - if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) { - __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); - - if (tpi->flags&TUNNEL_SEQ) { - *ptr = tpi->seq; - ptr--; - } - if (tpi->flags&TUNNEL_KEY) { - *ptr = tpi->key; - ptr--; - } - if (tpi->flags&TUNNEL_CSUM && - !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) { - *ptr = 0; - *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, - skb->len, 0)); - } - } -} -EXPORT_SYMBOL_GPL(gre_build_header); - -struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum) -{ - int err; - - if (likely(!skb->encapsulation)) { - skb_reset_inner_headers(skb); - skb->encapsulation = 1; - } - - if (skb_is_gso(skb)) { - err = skb_unclone(skb, GFP_ATOMIC); - if (unlikely(err)) - goto error; - skb_shinfo(skb)->gso_type |= SKB_GSO_GRE; - return skb; - } else if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) { - err = skb_checksum_help(skb); - if (unlikely(err)) - goto error; - } else if (skb->ip_summed != CHECKSUM_PARTIAL) - skb->ip_summed = CHECKSUM_NONE; - - return skb; -error: - kfree_skb(skb); - return ERR_PTR(err); -} -EXPORT_SYMBOL_GPL(gre_handle_offloads); - -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 parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, - bool *csum_err) -{ - unsigned int ip_hlen = ip_hdrlen(skb); - const struct gre_base_hdr *greh; - __be32 *options; - int hdr_len; - - 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 iptunnel_pull_header(skb, hdr_len, tpi->proto); -} - -static int gre_cisco_rcv(struct sk_buff *skb) -{ - struct tnl_ptk_info tpi; - int i; - bool csum_err = false; - - if (parse_gre_header(skb, &tpi, &csum_err) < 0) - goto drop; - - rcu_read_lock(); - for (i = 0; i < GRE_IP_PROTO_MAX; i++) { - struct gre_cisco_protocol *proto; - int ret; - - proto = rcu_dereference(gre_cisco_proto_list[i]); - if (!proto) - continue; - ret = proto->handler(skb, &tpi); - if (ret == PACKET_RCVD) { - rcu_read_unlock(); - return 0; - } - } - rcu_read_unlock(); - - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); -drop: - kfree_skb(skb); - return 0; -} - -static void gre_cisco_err(struct sk_buff *skb, u32 info) -{ - /* All the routers (except for Linux) return only - * 8 bytes of packet payload. It means, that precise relaying of - * ICMP in the real Internet is absolutely infeasible. - * - * Moreover, Cisco "wise men" put GRE key to the third word - * in GRE header. It makes impossible maintaining even soft - * state for keyed - * GRE tunnels with enabled checksum. Tell them "thank you". - * - * Well, I wonder, rfc1812 was written by Cisco employee, - * what the hell these idiots break standards established - * by themselves??? - */ - - const int type = icmp_hdr(skb)->type; - const int code = icmp_hdr(skb)->code; - struct tnl_ptk_info tpi; - bool csum_err = false; - int i; - - if (parse_gre_header(skb, &tpi, &csum_err)) { - if (!csum_err) /* ignore csum errors. */ - return; - } - - if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { - ipv4_update_pmtu(skb, dev_net(skb->dev), info, - skb->dev->ifindex, 0, IPPROTO_GRE, 0); - return; - } - if (type == ICMP_REDIRECT) { - ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, - IPPROTO_GRE, 0); - return; - } - - rcu_read_lock(); - for (i = 0; i < GRE_IP_PROTO_MAX; i++) { - struct gre_cisco_protocol *proto; - - proto = rcu_dereference(gre_cisco_proto_list[i]); - if (!proto) - continue; - - if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD) - goto out; - - } -out: - rcu_read_unlock(); -} - -static int gre_rcv(struct sk_buff *skb) -{ - const struct gre_protocol *proto; - u8 ver; - int ret; - - if (!pskb_may_pull(skb, 12)) - goto drop; - - ver = skb->data[1]&0x7f; - if (ver >= GREPROTO_MAX) - goto drop; - - rcu_read_lock(); - proto = rcu_dereference(gre_proto[ver]); - if (!proto || !proto->handler) - goto drop_unlock; - ret = proto->handler(skb); - rcu_read_unlock(); - return ret; - -drop_unlock: - rcu_read_unlock(); -drop: - kfree_skb(skb); - return NET_RX_DROP; -} - -static void gre_err(struct sk_buff *skb, u32 info) -{ - const struct gre_protocol *proto; - const struct iphdr *iph = (const struct iphdr *)skb->data; - u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f; - - if (ver >= GREPROTO_MAX) - return; - - rcu_read_lock(); - proto = rcu_dereference(gre_proto[ver]); - if (proto && proto->err_handler) - proto->err_handler(skb, info); - rcu_read_unlock(); -} - -static struct sk_buff *gre_gso_segment(struct sk_buff *skb, - netdev_features_t features) -{ - struct sk_buff *segs = ERR_PTR(-EINVAL); - netdev_features_t enc_features; - int ghl = GRE_HEADER_SECTION; - struct gre_base_hdr *greh; - int mac_len = skb->mac_len; - __be16 protocol = skb->protocol; - int tnl_hlen; - bool csum; - - if (unlikely(skb_shinfo(skb)->gso_type & - ~(SKB_GSO_TCPV4 | - SKB_GSO_TCPV6 | - SKB_GSO_UDP | - SKB_GSO_DODGY | - SKB_GSO_TCP_ECN | - SKB_GSO_GRE))) - goto out; - - if (unlikely(!pskb_may_pull(skb, sizeof(*greh)))) - goto out; - - greh = (struct gre_base_hdr *)skb_transport_header(skb); - - if (greh->flags & GRE_KEY) - ghl += GRE_HEADER_SECTION; - if (greh->flags & GRE_SEQ) - ghl += GRE_HEADER_SECTION; - if (greh->flags & GRE_CSUM) { - ghl += GRE_HEADER_SECTION; - csum = true; - } else - csum = false; - - /* setup inner skb. */ - skb->protocol = greh->protocol; - skb->encapsulation = 0; - - if (unlikely(!pskb_may_pull(skb, ghl))) - goto out; - __skb_pull(skb, ghl); - skb_reset_mac_header(skb); - skb_set_network_header(skb, skb_inner_network_offset(skb)); - skb->mac_len = skb_inner_network_offset(skb); - - /* segment inner packet. */ - enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); - segs = skb_mac_gso_segment(skb, enc_features); - if (!segs || IS_ERR(segs)) - goto out; - - skb = segs; - tnl_hlen = skb_tnl_header_len(skb); - do { - __skb_push(skb, ghl); - if (csum) { - __be32 *pcsum; - - if (skb_has_shared_frag(skb)) { - int err; - - err = __skb_linearize(skb); - if (err) { - kfree_skb(segs); - segs = ERR_PTR(err); - goto out; - } - } - - greh = (struct gre_base_hdr *)(skb->data); - pcsum = (__be32 *)(greh + 1); - *pcsum = 0; - *(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0)); - } - __skb_push(skb, tnl_hlen - ghl); - - skb_reset_mac_header(skb); - skb_set_network_header(skb, mac_len); - skb->mac_len = mac_len; - skb->protocol = protocol; - } while ((skb = skb->next)); -out: - return segs; -} - -static int gre_gso_send_check(struct sk_buff *skb) -{ - if (!skb->encapsulation) - return -EINVAL; - return 0; -} - -static const struct net_protocol net_gre_protocol = { - .handler = gre_rcv, - .err_handler = gre_err, - .netns_ok = 1, -}; - -static const struct net_offload gre_offload = { - .callbacks = { - .gso_send_check = gre_gso_send_check, - .gso_segment = gre_gso_segment, - }, -}; - -static const struct gre_protocol ipgre_protocol = { - .handler = gre_cisco_rcv, - .err_handler = gre_cisco_err, -}; - -int gre_cisco_register(struct gre_cisco_protocol *newp) -{ - struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) - &gre_cisco_proto_list[newp->priority]; - - return (cmpxchg(proto, NULL, newp) == NULL) ? 0 : -EBUSY; -} -EXPORT_SYMBOL_GPL(gre_cisco_register); - -int gre_cisco_unregister(struct gre_cisco_protocol *del_proto) -{ - struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) - &gre_cisco_proto_list[del_proto->priority]; - int ret; - - ret = (cmpxchg(proto, del_proto, NULL) == del_proto) ? 0 : -EINVAL; - - if (ret) - return ret; - - synchronize_net(); - return 0; -} -EXPORT_SYMBOL_GPL(gre_cisco_unregister); - -static int __init gre_init(void) -{ - pr_info("GRE over IPv4 demultiplexor driver\n"); - - if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) { - pr_err("can't add protocol\n"); - goto err; - } - - if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) { - pr_info("%s: can't add ipgre handler\n", __func__); - goto err_gre; - } - - if (inet_add_offload(&gre_offload, IPPROTO_GRE)) { - pr_err("can't add protocol offload\n"); - goto err_gso; - } - - return 0; -err_gso: - gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); -err_gre: - inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); -err: - return -EAGAIN; -} - -static void __exit gre_exit(void) -{ - inet_del_offload(&gre_offload, IPPROTO_GRE); - gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); - inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); -} - -module_init(gre_init); -module_exit(gre_exit); - -MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver"); -MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); -MODULE_LICENSE("GPL"); diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c new file mode 100644 index 000000000000..736c9fc3ef93 --- /dev/null +++ b/net/ipv4/gre_demux.c @@ -0,0 +1,414 @@ +/* + * GRE over IPv4 demultiplexer driver + * + * Authors: Dmitry Kozlov (xeb@mail.ru) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly; +static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX]; + +int gre_add_protocol(const struct gre_protocol *proto, u8 version) +{ + if (version >= GREPROTO_MAX) + return -EINVAL; + + return (cmpxchg((const struct gre_protocol **)&gre_proto[version], NULL, proto) == NULL) ? + 0 : -EBUSY; +} +EXPORT_SYMBOL_GPL(gre_add_protocol); + +int gre_del_protocol(const struct gre_protocol *proto, u8 version) +{ + int ret; + + if (version >= GREPROTO_MAX) + return -EINVAL; + + ret = (cmpxchg((const struct gre_protocol **)&gre_proto[version], proto, NULL) == proto) ? + 0 : -EBUSY; + + if (ret) + return ret; + + synchronize_rcu(); + return 0; +} +EXPORT_SYMBOL_GPL(gre_del_protocol); + +void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi, + int hdr_len) +{ + struct gre_base_hdr *greh; + + skb_push(skb, hdr_len); + + greh = (struct gre_base_hdr *)skb->data; + greh->flags = tnl_flags_to_gre_flags(tpi->flags); + greh->protocol = tpi->proto; + + if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) { + __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); + + if (tpi->flags&TUNNEL_SEQ) { + *ptr = tpi->seq; + ptr--; + } + if (tpi->flags&TUNNEL_KEY) { + *ptr = tpi->key; + ptr--; + } + if (tpi->flags&TUNNEL_CSUM && + !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) { + *ptr = 0; + *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, + skb->len, 0)); + } + } +} +EXPORT_SYMBOL_GPL(gre_build_header); + +struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum) +{ + int err; + + if (likely(!skb->encapsulation)) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + if (skb_is_gso(skb)) { + err = skb_unclone(skb, GFP_ATOMIC); + if (unlikely(err)) + goto error; + skb_shinfo(skb)->gso_type |= SKB_GSO_GRE; + return skb; + } else if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) { + err = skb_checksum_help(skb); + if (unlikely(err)) + goto error; + } else if (skb->ip_summed != CHECKSUM_PARTIAL) + skb->ip_summed = CHECKSUM_NONE; + + return skb; +error: + kfree_skb(skb); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(gre_handle_offloads); + +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 parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, + bool *csum_err) +{ + unsigned int ip_hlen = ip_hdrlen(skb); + const struct gre_base_hdr *greh; + __be32 *options; + int hdr_len; + + 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 iptunnel_pull_header(skb, hdr_len, tpi->proto); +} + +static int gre_cisco_rcv(struct sk_buff *skb) +{ + struct tnl_ptk_info tpi; + int i; + bool csum_err = false; + + if (parse_gre_header(skb, &tpi, &csum_err) < 0) + goto drop; + + rcu_read_lock(); + for (i = 0; i < GRE_IP_PROTO_MAX; i++) { + struct gre_cisco_protocol *proto; + int ret; + + proto = rcu_dereference(gre_cisco_proto_list[i]); + if (!proto) + continue; + ret = proto->handler(skb, &tpi); + if (ret == PACKET_RCVD) { + rcu_read_unlock(); + return 0; + } + } + rcu_read_unlock(); + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); +drop: + kfree_skb(skb); + return 0; +} + +static void gre_cisco_err(struct sk_buff *skb, u32 info) +{ + /* All the routers (except for Linux) return only + * 8 bytes of packet payload. It means, that precise relaying of + * ICMP in the real Internet is absolutely infeasible. + * + * Moreover, Cisco "wise men" put GRE key to the third word + * in GRE header. It makes impossible maintaining even soft + * state for keyed + * GRE tunnels with enabled checksum. Tell them "thank you". + * + * Well, I wonder, rfc1812 was written by Cisco employee, + * what the hell these idiots break standards established + * by themselves??? + */ + + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct tnl_ptk_info tpi; + bool csum_err = false; + int i; + + if (parse_gre_header(skb, &tpi, &csum_err)) { + if (!csum_err) /* ignore csum errors. */ + return; + } + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { + ipv4_update_pmtu(skb, dev_net(skb->dev), info, + skb->dev->ifindex, 0, IPPROTO_GRE, 0); + return; + } + if (type == ICMP_REDIRECT) { + ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, + IPPROTO_GRE, 0); + return; + } + + rcu_read_lock(); + for (i = 0; i < GRE_IP_PROTO_MAX; i++) { + struct gre_cisco_protocol *proto; + + proto = rcu_dereference(gre_cisco_proto_list[i]); + if (!proto) + continue; + + if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD) + goto out; + + } +out: + rcu_read_unlock(); +} + +static int gre_rcv(struct sk_buff *skb) +{ + const struct gre_protocol *proto; + u8 ver; + int ret; + + if (!pskb_may_pull(skb, 12)) + goto drop; + + ver = skb->data[1]&0x7f; + if (ver >= GREPROTO_MAX) + goto drop; + + rcu_read_lock(); + proto = rcu_dereference(gre_proto[ver]); + if (!proto || !proto->handler) + goto drop_unlock; + ret = proto->handler(skb); + rcu_read_unlock(); + return ret; + +drop_unlock: + rcu_read_unlock(); +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +static void gre_err(struct sk_buff *skb, u32 info) +{ + const struct gre_protocol *proto; + const struct iphdr *iph = (const struct iphdr *)skb->data; + u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f; + + if (ver >= GREPROTO_MAX) + return; + + rcu_read_lock(); + proto = rcu_dereference(gre_proto[ver]); + if (proto && proto->err_handler) + proto->err_handler(skb, info); + rcu_read_unlock(); +} + +static const struct net_protocol net_gre_protocol = { + .handler = gre_rcv, + .err_handler = gre_err, + .netns_ok = 1, +}; + +static const struct gre_protocol ipgre_protocol = { + .handler = gre_cisco_rcv, + .err_handler = gre_cisco_err, +}; + +int gre_cisco_register(struct gre_cisco_protocol *newp) +{ + struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) + &gre_cisco_proto_list[newp->priority]; + + return (cmpxchg(proto, NULL, newp) == NULL) ? 0 : -EBUSY; +} +EXPORT_SYMBOL_GPL(gre_cisco_register); + +int gre_cisco_unregister(struct gre_cisco_protocol *del_proto) +{ + struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) + &gre_cisco_proto_list[del_proto->priority]; + int ret; + + ret = (cmpxchg(proto, del_proto, NULL) == del_proto) ? 0 : -EINVAL; + + if (ret) + return ret; + + synchronize_net(); + return 0; +} +EXPORT_SYMBOL_GPL(gre_cisco_unregister); + +static int __init gre_init(void) +{ + pr_info("GRE over IPv4 demultiplexor driver\n"); + + if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) { + pr_err("can't add protocol\n"); + goto err; + } + + if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) { + pr_info("%s: can't add ipgre handler\n", __func__); + goto err_gre; + } + + if (gre_offload_init()) { + pr_err("can't add protocol offload\n"); + goto err_gso; + } + + return 0; +err_gso: + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); +err_gre: + inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); +err: + return -EAGAIN; +} + +static void __exit gre_exit(void) +{ + gre_offload_exit(); + + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); + inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); +} + +module_init(gre_init); +module_exit(gre_exit); + +MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver"); +MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c new file mode 100644 index 000000000000..a9d8cd2bff4b --- /dev/null +++ b/net/ipv4/gre_offload.c @@ -0,0 +1,127 @@ +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * GRE GSO support + */ + +#include +#include +#include + +static int gre_gso_send_check(struct sk_buff *skb) +{ + if (!skb->encapsulation) + return -EINVAL; + return 0; +} + +static struct sk_buff *gre_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + netdev_features_t enc_features; + int ghl = GRE_HEADER_SECTION; + struct gre_base_hdr *greh; + int mac_len = skb->mac_len; + __be16 protocol = skb->protocol; + int tnl_hlen; + bool csum; + + if (unlikely(skb_shinfo(skb)->gso_type & + ~(SKB_GSO_TCPV4 | + SKB_GSO_TCPV6 | + SKB_GSO_UDP | + SKB_GSO_DODGY | + SKB_GSO_TCP_ECN | + SKB_GSO_GRE))) + goto out; + + if (unlikely(!pskb_may_pull(skb, sizeof(*greh)))) + goto out; + + greh = (struct gre_base_hdr *)skb_transport_header(skb); + + if (greh->flags & GRE_KEY) + ghl += GRE_HEADER_SECTION; + if (greh->flags & GRE_SEQ) + ghl += GRE_HEADER_SECTION; + if (greh->flags & GRE_CSUM) { + ghl += GRE_HEADER_SECTION; + csum = true; + } else + csum = false; + + /* setup inner skb. */ + skb->protocol = greh->protocol; + skb->encapsulation = 0; + + if (unlikely(!pskb_may_pull(skb, ghl))) + goto out; + + __skb_pull(skb, ghl); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb_inner_network_offset(skb)); + skb->mac_len = skb_inner_network_offset(skb); + + /* segment inner packet. */ + enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); + segs = skb_mac_gso_segment(skb, enc_features); + if (!segs || IS_ERR(segs)) + goto out; + + skb = segs; + tnl_hlen = skb_tnl_header_len(skb); + do { + __skb_push(skb, ghl); + if (csum) { + __be32 *pcsum; + + if (skb_has_shared_frag(skb)) { + int err; + + err = __skb_linearize(skb); + if (err) { + kfree_skb(segs); + segs = ERR_PTR(err); + goto out; + } + } + + greh = (struct gre_base_hdr *)(skb->data); + pcsum = (__be32 *)(greh + 1); + *pcsum = 0; + *(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0)); + } + __skb_push(skb, tnl_hlen - ghl); + + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + skb->mac_len = mac_len; + skb->protocol = protocol; + } while ((skb = skb->next)); +out: + return segs; +} + +static const struct net_offload gre_offload = { + .callbacks = { + .gso_send_check = gre_gso_send_check, + .gso_segment = gre_gso_segment, + }, +}; + +int __init gre_offload_init(void) +{ + return inet_add_offload(&gre_offload, IPPROTO_GRE); +} + +void __exit gre_offload_exit(void) +{ + inet_del_offload(&gre_offload, IPPROTO_GRE); +}