From 1cdbcb7957cf9e5f841dbcde9b38fd18a804208b Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Sun, 19 May 2013 15:46:49 +0000 Subject: net: Loosen constraints for recalculating checksum in skb_segment() This is a generic solution to resolve a specific problem that I have observed. If the encapsulation of an skb changes then ability to offload checksums may also change. In particular it may be necessary to perform checksumming in software. An example of such a case is where a non-GRE packet is received but is to be encapsulated and transmitted as GRE. Another example relates to my proposed support for for packets that are non-MPLS when received but MPLS when transmitted. The cost of this change is that the value of the csum variable may be checked when it previously was not. In the case where the csum variable is true this is pure overhead. In the case where the csum variable is false it leads to software checksumming, which I believe also leads to correct checksums in transmitted packets for the cases described above. Further analysis: This patch relies on the return value of can_checksum_protocol() being correct and in turn the return value of skb_network_protocol(), used to provide the protocol parameter of can_checksum_protocol(), being correct. It also relies on the features passed to skb_segment() and in turn to can_checksum_protocol() being correct. I believe that this problem has not been observed for VLANs because it appears that almost all drivers, the exception being xgbe, set vlan_features such that that the checksum offload support for VLAN packets is greater than or equal to that of non-VLAN packets. I wonder if the code in xgbe may be an oversight and the hardware does support checksumming of VLAN packets. If so it may be worth updating the vlan_features of the driver as this patch will force such checksums to be performed in software rather than hardware. Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index af9185d0be6..d6298914f4e 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2853,7 +2853,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) doffset + tnl_hlen); if (fskb != skb_shinfo(skb)->frag_list) - continue; + goto perform_csum_check; if (!sg) { nskb->ip_summed = CHECKSUM_NONE; @@ -2917,6 +2917,7 @@ skip_fraglist: nskb->len += nskb->data_len; nskb->truesize += nskb->data_len; +perform_csum_check: if (!csum) { nskb->csum = skb_checksum(nskb, doffset, nskb->len - doffset, 0); -- cgit v1.2.3-18-g5258 From 06ecf24bdf2b7afc6c8fd13de6dba2a96dd331b6 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 28 May 2013 13:15:50 -0700 Subject: net: Fix build warnings after mac_header and transport_header became __u16. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit net/core/skbuff.c: In function ‘__alloc_skb_head’: net/core/skbuff.c:203:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] net/core/skbuff.c: In function ‘__alloc_skb’: net/core/skbuff.c:279:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] net/core/skbuff.c:280:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] net/core/skbuff.c: In function ‘build_skb’: net/core/skbuff.c:348:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] net/core/skbuff.c:349:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] Signed-off-by: David S. Miller --- net/core/skbuff.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d6298914f4e..f45de077ab9 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -200,7 +200,7 @@ struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node) atomic_set(&skb->users, 1); #ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = ~0U; + skb->mac_header = (__u16) ~0U; #endif out: return skb; @@ -276,8 +276,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, skb_reset_tail_pointer(skb); skb->end = skb->tail + size; #ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = ~0U; - skb->transport_header = ~0U; + skb->mac_header = (__u16) ~0U; + skb->transport_header = (__u16) ~0U; #endif /* make sure we initialize shinfo sequentially */ @@ -345,8 +345,8 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) skb_reset_tail_pointer(skb); skb->end = skb->tail + size; #ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = ~0U; - skb->transport_header = ~0U; + skb->mac_header = (__u16) ~0U; + skb->transport_header = (__u16) ~0U; #endif /* make sure we initialize shinfo sequentially */ -- cgit v1.2.3-18-g5258 From 35d0461061f27eeb62de63174959edbbb9e434de Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 29 May 2013 15:16:05 +0800 Subject: net: clean up skb headers code commit 1a37e412a0225fcba5587 (net: Use 16bits for *_headers fields of struct skbuff) converts skb->*_header to u16, some #if NET_SKBUFF_DATA_USES_OFFSET are now useless, and to be safe, we could just use "X = (typeof(X)) ~0U;" as suggested by David. Cc: David S. Miller Cc: Simon Horman Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/core/skbuff.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index f45de077ab9..6b1b52c5593 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -199,9 +199,7 @@ struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node) skb->truesize = sizeof(struct sk_buff); atomic_set(&skb->users, 1); -#ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = (__u16) ~0U; -#endif + skb->mac_header = (typeof(skb->mac_header))~0U; out: return skb; } @@ -275,10 +273,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, skb->data = data; skb_reset_tail_pointer(skb); skb->end = skb->tail + size; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = (__u16) ~0U; - skb->transport_header = (__u16) ~0U; -#endif + skb->mac_header = (typeof(skb->mac_header))~0U; + skb->transport_header = (typeof(skb->transport_header))~0U; /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); @@ -344,10 +340,8 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) skb->data = data; skb_reset_tail_pointer(skb); skb->end = skb->tail + size; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = (__u16) ~0U; - skb->transport_header = (__u16) ~0U; -#endif + skb->mac_header = (typeof(skb->mac_header))~0U; + skb->transport_header = (typeof(skb->transport_header))~0U; /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); -- cgit v1.2.3-18-g5258 From 060212928670593fb89243640bf05cf89560b023 Mon Sep 17 00:00:00 2001 From: Eliezer Tamir Date: Mon, 10 Jun 2013 11:39:50 +0300 Subject: net: add low latency socket poll Adds an ndo_ll_poll method and the code that supports it. This method can be used by low latency applications to busy-poll Ethernet device queues directly from the socket code. sysctl_net_ll_poll controls how many microseconds to poll. Default is zero (disabled). Individual protocol support will be added by subsequent patches. Signed-off-by: Alexander Duyck Signed-off-by: Jesse Brandeburg Signed-off-by: Eliezer Tamir Acked-by: Eric Dumazet Tested-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/core/skbuff.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 73f57a0e152..4a4181e16c1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -733,6 +733,10 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) new->vlan_tci = old->vlan_tci; skb_copy_secmark(new, old); + +#ifdef CONFIG_NET_LL_RX_POLL + new->napi_id = old->napi_id; +#endif } /* -- cgit v1.2.3-18-g5258 From b41abb42bf62a85a32c41dab873220598a6ee266 Mon Sep 17 00:00:00 2001 From: "Peter Pan(潘卫平)" Date: Thu, 6 Jun 2013 21:27:21 +0800 Subject: net: pass correct parameter to skb_headers_offset_update() Since commit 1a37e412a022(net: Use 16bits for *_headers fields of struct skbuff), skb->*_header are relative to skb->head, so copy_skb_header() should not call skb_headers_offset_update() now, and we should pass correct parameter to skb_headers_offset_update() in pskb_expand_head() and skb_copy_expand(). Signed-off-by: Weiping Pan Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- net/core/skbuff.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4a4181e16c1..edf37578e21 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -909,18 +909,8 @@ static void skb_headers_offset_update(struct sk_buff *skb, int off) static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) { -#ifndef NET_SKBUFF_DATA_USES_OFFSET - /* - * Shift between the two data areas in bytes - */ - unsigned long offset = new->data - old->data; -#endif - __copy_skb_header(new, old); -#ifndef NET_SKBUFF_DATA_USES_OFFSET - skb_headers_offset_update(new, offset); -#endif skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size; skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs; skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type; @@ -1112,7 +1102,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, skb->end = skb->head + size; #endif skb->tail += off; - skb_headers_offset_update(skb, off); + skb_headers_offset_update(skb, nhead); /* Only adjust this if it actually is csum_start rather than csum */ if (skb->ip_summed == CHECKSUM_PARTIAL) skb->csum_start += nhead; @@ -1207,9 +1197,8 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, off = newheadroom - oldheadroom; if (n->ip_summed == CHECKSUM_PARTIAL) n->csum_start += off; -#ifdef NET_SKBUFF_DATA_USES_OFFSET + skb_headers_offset_update(n, off); -#endif return n; } -- cgit v1.2.3-18-g5258 From aeb193ea6cef28e33589de05ef932424f8e19bde Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Sun, 23 Jun 2013 23:33:48 -0700 Subject: net: Unmap fragment page once iterator is done Callers of skb_seq_read() are currently forced to call skb_abort_seq_read() even when consuming all the data because the last call to skb_seq_read (the one that returns 0 to indicate the end) fails to unmap the last fragment page. With this patch callers will be allowed to traverse the SKB data by calling skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally intended (and documented in the original commit 677e90eda), that is, only call skb_abort_seq_read() if the sequential read is actually aborted. Signed-off-by: Wedson Almeida Filho Signed-off-by: David S. Miller --- net/core/skbuff.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index edf37578e21..9f73eca29fb 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2541,8 +2541,13 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data, unsigned int block_limit, abs_offset = consumed + st->lower_offset; skb_frag_t *frag; - if (unlikely(abs_offset >= st->upper_offset)) + if (unlikely(abs_offset >= st->upper_offset)) { + if (st->frag_data) { + kunmap_atomic(st->frag_data); + st->frag_data = NULL; + } return 0; + } next_skb: block_limit = skb_headlen(st->cur_skb) + st->stepped_offset; -- cgit v1.2.3-18-g5258 From 621e84d6f373dcb273ebfd772638b8e7dc3c2c48 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Wed, 26 Jun 2013 16:11:27 +0200 Subject: dev: introduce skb_scrub_packet() The goal of this new function is to perform all needed cleanup before sending an skb into another netns. Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/core/skbuff.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9f73eca29fb..b1fcb8727e5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3492,3 +3492,26 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, return true; } EXPORT_SYMBOL(skb_try_coalesce); + +/** + * skb_scrub_packet - scrub an skb before sending it to another netns + * + * @skb: buffer to clean + * + * skb_scrub_packet can be used to clean an skb before injecting it in + * another namespace. We have to clear all information in the skb that + * could impact namespace isolation. + */ +void skb_scrub_packet(struct sk_buff *skb) +{ + skb_orphan(skb); + skb->tstamp.tv64 = 0; + skb->pkt_type = PACKET_HOST; + skb->skb_iif = 0; + skb_dst_drop(skb); + skb->mark = 0; + secpath_reset(skb); + nf_reset(skb); + nf_reset_trace(skb); +} +EXPORT_SYMBOL_GPL(skb_scrub_packet); -- cgit v1.2.3-18-g5258 From 4bc41b84e9b4d904f68cba2dbe0c60a5428c27c4 Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Wed, 3 Jul 2013 16:04:25 +0900 Subject: core: Copy inner_protocol in copy_skb_header() inner_protocol was added to struct sk_buff in 0d89d2035fe063461a5ddb609b2c12e7fb006e44 ("MPLS: Add limited GSO support"), which is scheduled to be included in v3.11. That patch did not update __copy_skb_header to copy the inner_protocol. Signed-off-by: Joe Stringer Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- net/core/skbuff.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 77971a35d6e..724bb7cb173 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -697,6 +697,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) new->transport_header = old->transport_header; new->network_header = old->network_header; new->mac_header = old->mac_header; + new->inner_protocol = old->inner_protocol; new->inner_transport_header = old->inner_transport_header; new->inner_network_header = old->inner_network_header; new->inner_mac_header = old->inner_mac_header; -- cgit v1.2.3-18-g5258 From 40dadff26539d1695d2a37b44f66c53158439ae9 Mon Sep 17 00:00:00 2001 From: Sunghan Suh Date: Fri, 12 Jul 2013 16:17:23 +0900 Subject: net: access page->private by using page_private Signed-off-by: Sunghan Suh Signed-off-by: David S. Miller --- net/core/skbuff.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 724bb7cb173..20e02d2605e 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -824,7 +824,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) page = alloc_page(gfp_mask); if (!page) { while (head) { - struct page *next = (struct page *)head->private; + struct page *next = (struct page *)page_private(head); put_page(head); head = next; } @@ -834,7 +834,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) memcpy(page_address(page), vaddr + f->page_offset, skb_frag_size(f)); kunmap_atomic(vaddr); - page->private = (unsigned long)head; + set_page_private(page, (unsigned long)head); head = page; } @@ -848,7 +848,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) for (i = num_frags - 1; i >= 0; i--) { __skb_fill_page_desc(skb, i, head, 0, skb_shinfo(skb)->frags[i].size); - head = (struct page *)head->private; + head = (struct page *)page_private(head); } skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY; -- cgit v1.2.3-18-g5258 From deceb4c062a8dd63fe554c3be2b4bf9151a5cedf Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 23 Jul 2013 20:22:39 +0100 Subject: net: fix comment above build_skb() build_skb() specifies that the data parameter must come from a kmalloc'd area, this is only true if frag_size equals 0, because then build_skb() will use kzsize(data) to figure out the actual data size. Update the comment to reflect that special condition. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 20e02d2605e..3df4d4ccf44 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -309,7 +309,8 @@ EXPORT_SYMBOL(__alloc_skb); * @frag_size: size of fragment, or 0 if head was kmalloced * * Allocate a new &sk_buff. Caller provides space holding head and - * skb_shared_info. @data must have been allocated by kmalloc() + * skb_shared_info. @data must have been allocated by kmalloc() only if + * @frag_size is 0, otherwise data should come from the page allocator. * The return is the new skb buffer. * On a failure the return is %NULL, and @data is not freed. * Notes : -- cgit v1.2.3-18-g5258 From e0d1095ae3405404d247afb00233ef837d58da83 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 1 Aug 2013 11:10:25 +0800 Subject: net: rename CONFIG_NET_LL_RX_POLL to CONFIG_NET_RX_BUSY_POLL Eliezer renames several *ll_poll to *busy_poll, but forgets CONFIG_NET_LL_RX_POLL, so in case of confusion, rename it too. Cc: Eliezer Tamir Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/core/skbuff.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/skbuff.c') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3df4d4ccf44..2c3d0f53d19 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -740,7 +740,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) skb_copy_secmark(new, old); -#ifdef CONFIG_NET_LL_RX_POLL +#ifdef CONFIG_NET_RX_BUSY_POLL new->napi_id = old->napi_id; #endif } -- cgit v1.2.3-18-g5258