/* * netsniff-ng - the packet sniffing beast * Copyright (C) 2012 Christoph Jaeger * Subject to the GPL, version 2. */ #ifndef PKT_BUFF_H #define PKT_BUFF_H #include "hash.h" #include "built_in.h" #include "proto.h" #include "xmalloc.h" struct pkt_buff { /* invariant: head <= data <= tail */ uint8_t *head; uint8_t *data; uint8_t *tail; unsigned int size; struct protocol *dissector; uint32_t link_type; uint16_t proto; }; static inline struct pkt_buff *pkt_alloc(uint8_t *packet, unsigned int len) { struct pkt_buff *pkt = xmalloc(sizeof(*pkt)); pkt->head = packet; pkt->data = packet; pkt->tail = packet + len; pkt->size = len; pkt->dissector = NULL; return pkt; } static inline void pkt_free(struct pkt_buff *pkt) { xfree(pkt); } static inline unsigned int pkt_len(struct pkt_buff *pkt) { bug_on(!pkt || pkt->data > pkt->tail); return pkt->tail - pkt->data; } static inline uint8_t *pkt_pull(struct pkt_buff *pkt, unsigned int len) { uint8_t *data = NULL; bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); if (len <= pkt_len(pkt)) { data = pkt->data; pkt->data += len; } bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); return data; } static inline uint8_t *pkt_peek(struct pkt_buff *pkt) { bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); return pkt->data; } static inline unsigned int pkt_trim(struct pkt_buff *pkt, unsigned int len) { unsigned int ret = 0; bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); if (len <= pkt_len(pkt)) ret = len; pkt->tail -= ret; bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); return ret; } static inline uint8_t *pkt_pull_tail(struct pkt_buff *pkt, unsigned int len) { uint8_t *tail = NULL; bug_on(!pkt || pkt->head > pkt->data || pkt->data > pkt->tail); if (len <= pkt_len(pkt)) { tail = pkt->tail; pkt->tail -= len; } return tail; } static inline void pkt_set_dissector(struct pkt_buff *pkt, struct hash_table *table, unsigned int key) { bug_on(!pkt || !table); pkt->dissector = lookup_hash(key, table); while (pkt->dissector && key != pkt->dissector->key) pkt->dissector = pkt->dissector->next; } #endif /* PKT_BUFF_H */ /option>

diff options

author	Feng Tang <feng.tang@intel.com>	2016-06-12 17:36:37 +0800
committer	David S. Miller <davem@davemloft.net>	2016-06-14 15:30:50 -0400
commit	881d0327db37ad917a367c77aff1afa1ee41e0a9 (patch)
tree	467c3a6ecf09440638b43a72da13ffed7a9a4232
parent	b46d9f625b07f843c706c2c7d0210a90ccdf143b (diff)

net: alx: Work around the DMA RX overflow issue

Commit 26c5f03 uses a new skb allocator to avoid the RFD overflow issue. But from debugging without datasheet, we found the error always happen when the DMA RX address is set to 0x....fc0, which is very likely to be a HW/silicon problem. So one idea is instead of adding a new allocator, why not just hitting the right target by avaiding the error-prone DMA address? This patch will actually * Remove the commit 26c5f03 * Apply rx skb with 64 bytes longer space, and if the allocated skb has a 0x...fc0 address, it will use skb_resever(skb, 64) to advance the address, so that the RX overflow can be avoided. In theory this method should also apply to atl1c driver, which I can't find anyone who can help to test on real devices. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761 Signed-off-by: Feng Tang <feng.tang@intel.com> Suggested-by: Eric Dumazet <edumazet@google.com> Tested-by: Ole Lukoie <olelukoie@mail.ru> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>