From 7b584460689d4326d2d1664271ab0c56b56d4328 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 23 Sep 2013 11:37:59 -0700 Subject: sctp: Remove extern from function prototypes There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'include/net/sctp') diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 3794c5ad20fe..c5fe80697f8d 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -90,12 +90,11 @@ /* * sctp/protocol.c */ -extern int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *, - sctp_scope_t, gfp_t gfp, - int flags); -extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family); -extern int sctp_register_pf(struct sctp_pf *, sa_family_t); -extern void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); +int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *, + sctp_scope_t, gfp_t gfp, int flags); +struct sctp_pf *sctp_get_pf_specific(sa_family_t family); +int sctp_register_pf(struct sctp_pf *, sa_family_t); +void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); /* * sctp/socket.c @@ -110,7 +109,7 @@ void sctp_sock_rfree(struct sk_buff *skb); void sctp_copy_sock(struct sock *newsk, struct sock *sk, struct sctp_association *asoc); extern struct percpu_counter sctp_sockets_allocated; -extern int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); +int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); /* * sctp/primitive.c -- cgit v1.2.3 From e6d8b64b34aa8a9fe39609bc2db8a243b0331ceb Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 30 Oct 2013 11:50:52 +0100 Subject: net: sctp: fix and consolidate SCTP checksumming code This fixes an outstanding bug found through IPVS, where SCTP packets with skb->data_len > 0 (non-linearized) and empty frag_list, but data accumulated in frags[] member, are forwarded with incorrect checksum letting SCTP initial handshake fail on some systems. Linearizing each SCTP skb in IPVS to prevent that would not be a good solution as this leads to an additional and unnecessary performance penalty on the load-balancer itself for no good reason (as we actually only want to update the checksum, and can do that in a different/better way presented here). The actual problem is elsewhere, namely, that SCTP's checksumming in sctp_compute_cksum() does not take frags[] into account like skb_checksum() does. So while we are fixing this up, we better reuse the existing code that we have anyway in __skb_checksum() and use it for walking through the data doing checksumming. This will not only fix this issue, but also consolidates some SCTP code with core sk_buff code, bringing it closer together and removing respectively avoiding reimplementation of skb_checksum() for no good reason. As crc32c() can use hardware implementation within the crypto layer, we leave that intact (it wraps around / falls back to e.g. slice-by-8 algorithm in __crc32c_le() otherwise); plus use the __crc32c_le_combine() combinator for crc32c blocks. Also, we remove all other SCTP checksumming code, so that we only have to use sctp_compute_cksum() from now on; for doing that, we need to transform SCTP checkumming in output path slightly, and can leave the rest intact. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/net/sctp/checksum.h | 56 +++++++++++++++------------------------------ 1 file changed, 19 insertions(+), 37 deletions(-) (limited to 'include/net/sctp') diff --git a/include/net/sctp/checksum.h b/include/net/sctp/checksum.h index 259924d63ba6..6bd44fe94c26 100644 --- a/include/net/sctp/checksum.h +++ b/include/net/sctp/checksum.h @@ -42,56 +42,38 @@ #include #include #include +#include -static inline __u32 sctp_crc32c(__u32 crc, u8 *buffer, u16 length) +static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum) { - return crc32c(crc, buffer, length); -} - -static inline __u32 sctp_start_cksum(__u8 *buffer, __u16 length) -{ - __u32 crc = ~(__u32)0; - __u8 zero[sizeof(__u32)] = {0}; - - /* Optimize this routine to be SCTP specific, knowing how - * to skip the checksum field of the SCTP header. + /* This uses the crypto implementation of crc32c, which is either + * implemented w/ hardware support or resolves to __crc32c_le(). */ - - /* Calculate CRC up to the checksum. */ - crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32)); - - /* Skip checksum field of the header. */ - crc = sctp_crc32c(crc, zero, sizeof(__u32)); - - /* Calculate the rest of the CRC. */ - crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)], - length - sizeof(struct sctphdr)); - return crc; -} - -static inline __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32) -{ - return sctp_crc32c(crc32, buffer, length); + return crc32c(sum, buff, len); } -static inline __le32 sctp_end_cksum(__u32 crc32) +static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2, + int offset, int len) { - return cpu_to_le32(~crc32); + return __crc32c_le_combine(csum, csum2, len); } -/* Calculate the CRC32C checksum of an SCTP packet. */ static inline __le32 sctp_compute_cksum(const struct sk_buff *skb, unsigned int offset) { - const struct sk_buff *iter; + struct sctphdr *sh = sctp_hdr(skb); + __le32 ret, old = sh->checksum; + const struct skb_checksum_ops ops = { + .update = sctp_csum_update, + .combine = sctp_csum_combine, + }; - __u32 crc32 = sctp_start_cksum(skb->data + offset, - skb_headlen(skb) - offset); - skb_walk_frags(skb, iter) - crc32 = sctp_update_cksum((__u8 *) iter->data, - skb_headlen(iter), crc32); + sh->checksum = 0; + ret = cpu_to_le32(~__skb_checksum(skb, offset, skb->len - offset, + ~(__u32)0, &ops)); + sh->checksum = old; - return sctp_end_cksum(crc32); + return ret; } #endif /* __sctp_checksum_h__ */ -- cgit v1.2.3