diff options
Diffstat (limited to 'net/tipc/msg.c')
-rw-r--r-- | net/tipc/msg.c | 119 |
1 files changed, 84 insertions, 35 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c index b6eb90c..0c6dad8 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -1,7 +1,7 @@ /* * net/tipc/msg.c: TIPC message header routines * - * Copyright (c) 2000-2006, 2014, Ericsson AB + * Copyright (c) 2000-2006, 2014-2015, Ericsson AB * Copyright (c) 2005, 2010-2011, Wind River Systems * All rights reserved. * @@ -165,6 +165,9 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf) } if (fragid == LAST_FRAGMENT) { + TIPC_SKB_CB(head)->validated = false; + if (unlikely(!tipc_msg_validate(head))) + goto err; *buf = head; TIPC_SKB_CB(head)->tail = NULL; *headbuf = NULL; @@ -172,7 +175,6 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf) } *buf = NULL; return 0; - err: pr_warn_ratelimited("Unable to build fragment list\n"); kfree_skb(*buf); @@ -181,6 +183,48 @@ err: return 0; } +/* tipc_msg_validate - validate basic format of received message + * + * This routine ensures a TIPC message has an acceptable header, and at least + * as much data as the header indicates it should. The routine also ensures + * that the entire message header is stored in the main fragment of the message + * buffer, to simplify future access to message header fields. + * + * Note: Having extra info present in the message header or data areas is OK. + * TIPC will ignore the excess, under the assumption that it is optional info + * introduced by a later release of the protocol. + */ +bool tipc_msg_validate(struct sk_buff *skb) +{ + struct tipc_msg *msg; + int msz, hsz; + + if (unlikely(TIPC_SKB_CB(skb)->validated)) + return true; + if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE))) + return false; + + hsz = msg_hdr_sz(buf_msg(skb)); + if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE)) + return false; + if (unlikely(!pskb_may_pull(skb, hsz))) + return false; + + msg = buf_msg(skb); + if (unlikely(msg_version(msg) != TIPC_VERSION)) + return false; + + msz = msg_size(msg); + if (unlikely(msz < hsz)) + return false; + if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE)) + return false; + if (unlikely(skb->len < msz)) + return false; + + TIPC_SKB_CB(skb)->validated = true; + return true; +} /** * tipc_msg_build - create buffer chain containing specified header and data @@ -228,6 +272,7 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr)); msg_set_size(&pkthdr, pktmax); msg_set_fragm_no(&pkthdr, pktno); + msg_set_importance(&pkthdr, msg_importance(mhdr)); /* Prepare first fragment */ skb = tipc_buf_acquire(pktmax); @@ -286,33 +331,36 @@ error: /** * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one - * @list: the buffer chain of the existing buffer ("bundle") + * @bskb: the buffer to append to ("bundle") * @skb: buffer to be appended * @mtu: max allowable size for the bundle buffer * Consumes buffer if successful * Returns true if bundling could be performed, otherwise false */ -bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu) +bool tipc_msg_bundle(struct sk_buff *bskb, struct sk_buff *skb, u32 mtu) { - struct sk_buff *bskb = skb_peek_tail(list); - struct tipc_msg *bmsg = buf_msg(bskb); + struct tipc_msg *bmsg; struct tipc_msg *msg = buf_msg(skb); - unsigned int bsz = msg_size(bmsg); + unsigned int bsz; unsigned int msz = msg_size(msg); - u32 start = align(bsz); + u32 start, pad; u32 max = mtu - INT_H_SIZE; - u32 pad = start - bsz; if (likely(msg_user(msg) == MSG_FRAGMENTER)) return false; + if (!bskb) + return false; + bmsg = buf_msg(bskb); + bsz = msg_size(bmsg); + start = align(bsz); + pad = start - bsz; + if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL)) return false; if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) return false; if (likely(msg_user(bmsg) != MSG_BUNDLER)) return false; - if (likely(!TIPC_SKB_CB(bskb)->bundling)) - return false; if (unlikely(skb_tailroom(bskb) < (pad + msz))) return false; if (unlikely(max < (start + msz))) @@ -328,34 +376,40 @@ bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu) /** * tipc_msg_extract(): extract bundled inner packet from buffer - * @skb: linear outer buffer, to be extracted from. + * @skb: buffer to be extracted from. * @iskb: extracted inner buffer, to be returned - * @pos: position of msg to be extracted. Returns with pointer of next msg + * @pos: position in outer message of msg to be extracted. + * Returns position of next msg * Consumes outer buffer when last packet extracted * Returns true when when there is an extracted buffer, otherwise false */ bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos) { - struct tipc_msg *msg = buf_msg(skb); - int imsz; - struct tipc_msg *imsg = (struct tipc_msg *)(msg_data(msg) + *pos); + struct tipc_msg *msg; + int imsz, offset; + + *iskb = NULL; + if (unlikely(skb_linearize(skb))) + goto none; - /* Is there space left for shortest possible message? */ - if (*pos > (msg_data_sz(msg) - SHORT_H_SIZE)) + msg = buf_msg(skb); + offset = msg_hdr_sz(msg) + *pos; + if (unlikely(offset > (msg_size(msg) - MIN_H_SIZE))) goto none; - imsz = msg_size(imsg); - /* Is there space left for current message ? */ - if ((*pos + imsz) > msg_data_sz(msg)) + *iskb = skb_clone(skb, GFP_ATOMIC); + if (unlikely(!*iskb)) goto none; - *iskb = tipc_buf_acquire(imsz); - if (!*iskb) + skb_pull(*iskb, offset); + imsz = msg_size(buf_msg(*iskb)); + skb_trim(*iskb, imsz); + if (unlikely(!tipc_msg_validate(*iskb))) goto none; - skb_copy_to_linear_data(*iskb, imsg, imsz); *pos += align(imsz); return true; none: kfree_skb(skb); + kfree_skb(*iskb); *iskb = NULL; return false; } @@ -369,12 +423,11 @@ none: * Replaces buffer if successful * Returns true if success, otherwise false */ -bool tipc_msg_make_bundle(struct sk_buff_head *list, - struct sk_buff *skb, u32 mtu, u32 dnode) +bool tipc_msg_make_bundle(struct sk_buff **skb, u32 mtu, u32 dnode) { struct sk_buff *bskb; struct tipc_msg *bmsg; - struct tipc_msg *msg = buf_msg(skb); + struct tipc_msg *msg = buf_msg(*skb); u32 msz = msg_size(msg); u32 max = mtu - INT_H_SIZE; @@ -398,9 +451,9 @@ bool tipc_msg_make_bundle(struct sk_buff_head *list, msg_set_seqno(bmsg, msg_seqno(msg)); msg_set_ack(bmsg, msg_ack(msg)); msg_set_bcast_ack(bmsg, msg_bcast_ack(msg)); - TIPC_SKB_CB(bskb)->bundling = true; - __skb_queue_tail(list, bskb); - return tipc_msg_bundle(list, skb, mtu); + tipc_msg_bundle(bskb, *skb, mtu); + *skb = bskb; + return true; } /** @@ -415,21 +468,17 @@ bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode, int err) { struct tipc_msg *msg = buf_msg(buf); - uint imp = msg_importance(msg); struct tipc_msg ohdr; uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE); if (skb_linearize(buf)) goto exit; + msg = buf_msg(buf); if (msg_dest_droppable(msg)) goto exit; if (msg_errcode(msg)) goto exit; - memcpy(&ohdr, msg, msg_hdr_sz(msg)); - imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE); - if (msg_isdata(msg)) - msg_set_importance(msg, imp); msg_set_errcode(msg, err); msg_set_origport(msg, msg_destport(&ohdr)); msg_set_destport(msg, msg_origport(&ohdr)); |