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| author | Cong Wang <xiyou.wangcong@gmail.com> | 2018-03-26 15:08:33 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-27 11:56:00 -0400 |
| commit | b85ab56c3f81c5a24b5a5213374f549df06430da (patch) | |
| tree | 4580d5ab329020259c744ca5b5accae6997258c9 /net/llc/llc_conn.c | |
| parent | 2a7fdec98f74cc305c1247cbe67307d504a3223d (diff) | |
| download | linux-b85ab56c3f81c5a24b5a5213374f549df06430da.tar.gz linux-b85ab56c3f81c5a24b5a5213374f549df06430da.tar.bz2 linux-b85ab56c3f81c5a24b5a5213374f549df06430da.zip | |
llc: properly handle dev_queue_xmit() return value
llc_conn_send_pdu() pushes the skb into write queue and
calls llc_conn_send_pdus() to flush them out. However, the
status of dev_queue_xmit() is not returned to caller,
in this case, llc_conn_state_process().
llc_conn_state_process() needs hold the skb no matter
success or failure, because it still uses it after that,
therefore we should hold skb before dev_queue_xmit() when
that skb is the one being processed by llc_conn_state_process().
For other callers, they can just pass NULL and ignore
the return value as they are.
Reported-by: Noam Rathaus <noamr@beyondsecurity.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/llc/llc_conn.c')
| -rw-r--r-- | net/llc/llc_conn.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c index 9177dbb16dce..110e32bcb399 100644 --- a/net/llc/llc_conn.c +++ b/net/llc/llc_conn.c @@ -30,7 +30,7 @@ #endif static int llc_find_offset(int state, int ev_type); -static void llc_conn_send_pdus(struct sock *sk); +static int llc_conn_send_pdus(struct sock *sk, struct sk_buff *skb); static int llc_conn_service(struct sock *sk, struct sk_buff *skb); static int llc_exec_conn_trans_actions(struct sock *sk, struct llc_conn_state_trans *trans, @@ -193,11 +193,11 @@ out_skb_put: return rc; } -void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) +int llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) { /* queue PDU to send to MAC layer */ skb_queue_tail(&sk->sk_write_queue, skb); - llc_conn_send_pdus(sk); + return llc_conn_send_pdus(sk, skb); } /** @@ -255,7 +255,7 @@ void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit) if (howmany_resend > 0) llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; /* any PDUs to re-send are queued up; start sending to MAC */ - llc_conn_send_pdus(sk); + llc_conn_send_pdus(sk, NULL); out:; } @@ -296,7 +296,7 @@ void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit) if (howmany_resend > 0) llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; /* any PDUs to re-send are queued up; start sending to MAC */ - llc_conn_send_pdus(sk); + llc_conn_send_pdus(sk, NULL); out:; } @@ -340,12 +340,16 @@ out: /** * llc_conn_send_pdus - Sends queued PDUs * @sk: active connection + * @hold_skb: the skb held by caller, or NULL if does not care * - * Sends queued pdus to MAC layer for transmission. + * Sends queued pdus to MAC layer for transmission. When @hold_skb is + * NULL, always return 0. Otherwise, return 0 if @hold_skb is sent + * successfully, or 1 for failure. */ -static void llc_conn_send_pdus(struct sock *sk) +static int llc_conn_send_pdus(struct sock *sk, struct sk_buff *hold_skb) { struct sk_buff *skb; + int ret = 0; while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) { struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); @@ -357,10 +361,20 @@ static void llc_conn_send_pdus(struct sock *sk) skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb); if (!skb2) break; - skb = skb2; + dev_queue_xmit(skb2); + } else { + bool is_target = skb == hold_skb; + int rc; + + if (is_target) + skb_get(skb); + rc = dev_queue_xmit(skb); + if (is_target) + ret = rc; } - dev_queue_xmit(skb); } + + return ret; } /** |