[RFC PATCH] net: wget: Take in account tcp sequence number wrap around

Coming from some discussion on mailing about wget unconsistent. It's just and idea to play around
Signed-off-by: Michael Trimarchi michael@amarulasolutions.com ---
I'm on a train ;). No board to test
--- include/net/tcp.h | 10 ++++++++++ net/wget.c | 8 ++++---- 2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h index c29d4ce24a..584813b637 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -88,6 +88,16 @@ struct ip_tcp_hdr { #define TCP_MSS 1460 /* Max segment size */ #define TCP_SCALE 0x01 /* Scale */
+/* + * The next routines deal with comparing 32 bit unsigned ints + * and worry about wraparound (automatic with unsigned arithmetic). + */ +static inline bool before(__u32 seq1, __u32 seq2) +{ + return (__s32)(seq1-seq2) < 0; +} +#define after(seq2, seq1) before(seq1, seq2) + /** * struct tcp_mss - TCP option structure for MSS (Max segment size) * @kind: Field ID diff --git a/net/wget.c b/net/wget.c index 8bb4d72db1..99a688846f 100644 --- a/net/wget.c +++ b/net/wget.c @@ -260,8 +260,8 @@ static void wget_connected(uchar *pkt, unsigned int tcp_seq_num, (phys_addr_t)(pkt_q[i].pkt), pkt_q[i].len); store_block(ptr1, - pkt_q[i].tcp_seq_num - - initial_data_seq_num, + (unsigned int)((s32)pkt_q[i].tcp_seq_num - + (s32)initial_data_seq_num), pkt_q[i].len); unmap_sysmem(ptr1); debug_cond(DEBUG_WGET, @@ -333,8 +333,8 @@ static void wget_handler(uchar *pkt, u16 dport, "wget: Transferring, seq=%x, ack=%x,len=%x\n", tcp_seq_num, tcp_ack_num, len);
- if (tcp_seq_num >= initial_data_seq_num && - store_block(pkt, tcp_seq_num - initial_data_seq_num, + if (!before(initial_data_seq_num, tcp_seq_num) && + store_block(pkt, (unsigned int)((s32)tcp_seq_num - (s32)initial_data_seq_num), len) != 0) { wget_fail("wget: store error\n", tcp_seq_num, tcp_ack_num, action);
participants (1)
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Michael Trimarchi