Currently, we only dump a few selected skb fields in
netdev_rx_csum_fault(). It is not suffient for debugging checksum
fault. This patch introduces skb_dump() which dumps skb mac header,
network header and its whole skb->data too.
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: Eric Dumazet <eduma...@google.com>
Cc: David Miller <da...@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
include/linux/skbuff.h | 5 +++++
net/core/dev.c | 6 +-----
net/core/skbuff.c | 49 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+), 5 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index afddb5c17ce5..844c0a7ff52f 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4218,5 +4218,10 @@ static inline __wsum lco_csum(struct sk_buff *skb)
return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
}
+#ifdef CONFIG_BUG
+void skb_dump(const char *level, const struct sk_buff *skb, bool dump_header,
+ bool dump_mac_header, bool dump_network_header);
+#endif
+
#endif /* __KERNEL__ */
#endif /* _LINUX_SKBUFF_H */
diff --git a/net/core/dev.c b/net/core/dev.c
index f2bfd2eda7b2..dc54c89fb4b1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3097,11 +3097,7 @@ void netdev_rx_csum_fault(struct net_device *dev, struct
sk_buff *skb)
pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
if (dev)
pr_err("dev features: %pNF\n", &dev->features);
- pr_err("skb len=%u data_len=%u pkt_type=%u gso_size=%u
gso_type=%u nr_frags=%u ip_summed=%u csum=%x csum_complete_sw=%d csum_valid=%d
csum_level=%u\n",
- skb->len, skb->data_len, skb->pkt_type,
- skb_shinfo(skb)->gso_size, skb_shinfo(skb)->gso_type,
- skb_shinfo(skb)->nr_frags, skb->ip_summed, skb->csum,
- skb->csum_complete_sw, skb->csum_valid, skb->csum_level);
+ skb_dump(KERN_ERR, skb, true, true, true);
dump_stack();
}
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b6ba923e7dc7..21aaef3f6a4a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5555,3 +5555,52 @@ void skb_condense(struct sk_buff *skb)
*/
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
}
+
+#ifdef CONFIG_BUG
+void skb_dump(const char *level, const struct sk_buff *skb, bool dump_header,
+ bool dump_mac_header, bool dump_network_header)
+{
+ struct sk_buff *frag_iter;
+ int i;
+
+ if (dump_header)
+ printk("%sskb len=%u data_len=%u pkt_type=%u gso_size=%u
gso_type=%u nr_frags=%u ip_summed=%u csum=%x csum_complete_sw=%d csum_valid=%d
csum_level=%u\n",
+ level, skb->len, skb->data_len, skb->pkt_type,
+ skb_shinfo(skb)->gso_size, skb_shinfo(skb)->gso_type,
+ skb_shinfo(skb)->nr_frags, skb->ip_summed, skb->csum,
+ skb->csum_complete_sw, skb->csum_valid, skb->csum_level);
+
+ if (dump_mac_header && skb_mac_header_was_set(skb))
+ print_hex_dump(level, "mac header: ", DUMP_PREFIX_OFFSET, 16, 1,
+ skb_mac_header(skb), skb_mac_header_len(skb),
+ false);
+
+ if (dump_network_header && skb_network_header_was_set(skb))
+ print_hex_dump(level, "network header: ", DUMP_PREFIX_OFFSET,
+ 16, 1, skb_network_header(skb),
+ skb_network_header_len(skb), false);
+
+ print_hex_dump(level, "skb data: ", DUMP_PREFIX_OFFSET, 16, 1,
+ skb->data, skb->len, false);
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ u32 p_off, p_len, copied;
+ struct page *p;
+ u8 *vaddr;
+
+ skb_frag_foreach_page(frag, frag->page_offset,
skb_frag_size(frag),
+ p, p_off, p_len, copied) {
+ vaddr = kmap_atomic(p);
+ print_hex_dump(level, "skb frag: ", DUMP_PREFIX_OFFSET,
+ 16, 1, vaddr + p_off, p_len, false);
+ kunmap_atomic(vaddr);
+ }
+ }
+
+ if (skb_has_frag_list(skb))
+ printk("%sskb frags list:\n", level);
+ skb_walk_frags(skb, frag_iter)
+ skb_dump(level, frag_iter, false, false, false);
+}
+#endif
--
2.19.1
