/* * sctp_offload - GRO/GSO Offloading for SCTP * * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/kprobes.h> #include <linux/socket.h> #include <linux/sctp.h> #include <linux/proc_fs.h> #include <linux/vmalloc.h> #include <linux/module.h> #include <linux/kfifo.h> #include <linux/time.h> #include <net/net_namespace.h> #include <linux/skbuff.h> #include <net/sctp/sctp.h> #include <net/sctp/checksum.h> #include <net/protocol.h> static __le32 sctp_gso_make_checksum(struct sk_buff *skb) { skb->ip_summed = CHECKSUM_NONE; skb->csum_not_inet = 0; return sctp_compute_cksum(skb, skb_transport_offset(skb)); } static struct sk_buff *sctp_gso_segment(struct sk_buff *skb, netdev_features_t features) { struct sk_buff *segs = ERR_PTR(-EINVAL); struct sctphdr *sh; sh = sctp_hdr(skb); if (!pskb_may_pull(skb, sizeof(*sh))) goto out; __skb_pull(skb, sizeof(*sh)); if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { /* Packet is from an untrusted source, reset gso_segs. */ struct skb_shared_info *pinfo = skb_shinfo(skb); struct sk_buff *frag_iter; pinfo->gso_segs = 0; if (skb->len != skb->data_len) { /* Means we have chunks in here too */ pinfo->gso_segs++; } skb_walk_frags(skb, frag_iter) pinfo->gso_segs++; segs = NULL; goto out; } segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG); if (IS_ERR(segs)) goto out; /* All that is left is update SCTP CRC if necessary */ if (!(features & NETIF_F_SCTP_CRC)) { for (skb = segs; skb; skb = skb->next) { if (skb->ip_summed == CHECKSUM_PARTIAL) { sh = sctp_hdr(skb); sh->checksum = sctp_gso_make_checksum(skb); } } } out: return segs; } static const struct net_offload sctp_offload = { .callbacks = { .gso_segment = sctp_gso_segment, }, }; static const struct net_offload sctp6_offload = { .callbacks = { .gso_segment = sctp_gso_segment, }, }; static const struct skb_checksum_ops crc32c_csum_ops = { .update = sctp_csum_update, .combine = sctp_csum_combine, }; int __init sctp_offload_init(void) { int ret; ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP); if (ret) goto out; ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP); if (ret) goto ipv4; crc32c_csum_stub = &crc32c_csum_ops; return ret; ipv4: inet_del_offload(&sctp_offload, IPPROTO_SCTP); out: return ret; }