From cf2157f88a5abf1a64b8c51a737a35e918dc67e5 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Fri, 13 Mar 2015 16:08:06 -0400 Subject: tipc: move message validation function to msg.c The function link_buf_validate() is in reality re-entrant and context independent, and will in later commits be called from several locations. Therefore, we move it to msg.c, make it outline and rename the it to tipc_msg_validate(). We also redesign the function to make proper use of pskb_may_pull() Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 58 +-------------------------------------------------------- net/tipc/msg.c | 44 ++++++++++++++++++++++++++++++++++++++++++- net/tipc/msg.h | 5 +++-- 3 files changed, 47 insertions(+), 60 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index 98609fdfb06a..944c8c663a2d 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1047,61 +1047,6 @@ static void link_retrieve_defq(struct tipc_link *link, skb_queue_splice_tail_init(&link->deferred_queue, list); } -/** - * link_recv_buf_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. - */ -static int link_recv_buf_validate(struct sk_buff *buf) -{ - static u32 min_data_hdr_size[8] = { - SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE, - MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE - }; - - struct tipc_msg *msg; - u32 tipc_hdr[2]; - u32 size; - u32 hdr_size; - u32 min_hdr_size; - - /* If this packet comes from the defer queue, the skb has already - * been validated - */ - if (unlikely(TIPC_SKB_CB(buf)->deferred)) - return 1; - - if (unlikely(buf->len < MIN_H_SIZE)) - return 0; - - msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr); - if (msg == NULL) - return 0; - - if (unlikely(msg_version(msg) != TIPC_VERSION)) - return 0; - - size = msg_size(msg); - hdr_size = msg_hdr_sz(msg); - min_hdr_size = msg_isdata(msg) ? - min_data_hdr_size[msg_type(msg)] : INT_H_SIZE; - - if (unlikely((hdr_size < min_hdr_size) || - (size < hdr_size) || - (buf->len < size) || - (size - hdr_size > TIPC_MAX_USER_MSG_SIZE))) - return 0; - - return pskb_may_pull(buf, hdr_size); -} - /** * tipc_rcv - process TIPC packets/messages arriving from off-node * @net: the applicable net namespace @@ -1127,7 +1072,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) while ((skb = __skb_dequeue(&head))) { /* Ensure message is well-formed */ - if (unlikely(!link_recv_buf_validate(skb))) + if (unlikely(!tipc_msg_validate(skb))) goto discard; /* Ensure message data is a single contiguous unit */ @@ -1398,7 +1343,6 @@ static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr, if (tipc_link_defer_pkt(&l_ptr->deferred_queue, buf)) { l_ptr->stats.deferred_recv++; - TIPC_SKB_CB(buf)->deferred = true; if ((skb_queue_len(&l_ptr->deferred_queue) % 16) == 1) tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); } else { diff --git a/net/tipc/msg.c b/net/tipc/msg.c index b6eb90cd3ef7..4a64caf6fa20 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. * @@ -181,6 +181,48 @@ 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 diff --git a/net/tipc/msg.h b/net/tipc/msg.h index 7cece647394c..62306b8d2410 100644 --- a/net/tipc/msg.h +++ b/net/tipc/msg.h @@ -1,7 +1,7 @@ /* * net/tipc/msg.h: Include file for TIPC message header routines * - * Copyright (c) 2000-2007, 2014, Ericsson AB + * Copyright (c) 2000-2007, 2014-2015 Ericsson AB * Copyright (c) 2005-2008, 2010-2011, Wind River Systems * All rights reserved. * @@ -92,7 +92,7 @@ struct plist; struct tipc_skb_cb { void *handle; struct sk_buff *tail; - bool deferred; + bool validated; bool wakeup_pending; bool bundling; u16 chain_sz; @@ -758,6 +758,7 @@ static inline u32 msg_tot_origport(struct tipc_msg *m) } struct sk_buff *tipc_buf_acquire(u32 size); +bool tipc_msg_validate(struct sk_buff *skb); bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode, int err); void tipc_msg_init(u32 own_addr, struct tipc_msg *m, u32 user, u32 type, -- cgit v1.2.3