This patch tackles the following problem:
* the ccid3_hc_{t,r}x_sock define ccid3hc{t,r}x_state as `u8', but
in reality there can only be a few, pre-defined enum names
* this necessitates addiditional checking for unexpected values
which would otherwise be caught by the compiler
I am sending this as RFC since
(a) it extends an idea begun in Ian McDonalds 03-shift_tfrc_constant.diff
patch - Ian if you are ok with this patch, I add the signed-off line
(b) OK with the BUG behaviour (it seems that the combination
printk(KERN_CRIT ... ); dump_stack(); is preferrred); i.e. is a macro
#define DCCP_BUG(fmt, ##a) do { printk(KERN_CRIT, "%s: " fmt, __FUNCTION__, ##a); \
dump_stack(); } while (0)
?
Anyway, here is the patch, I think it makes things clearer:
---
net/dccp/ccids/ccid3.c | 69 ++++++++++++-------------------------------------
net/dccp/ccids/ccid3.h | 19 ++++++++++++-
2 files changed, 34 insertions(+), 54 deletions(-)
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -73,6 +73,14 @@ struct ccid3_options_received {
u32 ccid3or_receive_rate;
};
+/* TFRC sender states */
+enum ccid3_hc_tx_states {
+ TFRC_SSTATE_NO_SENT = 1,
+ TFRC_SSTATE_NO_FBACK,
+ TFRC_SSTATE_FBACK,
+ TFRC_SSTATE_TERM,
+};
+
/** struct ccid3_hc_tx_sock - CCID3 sender half connection sock
*
* @ccid3hctx_state - Sender state
@@ -103,7 +111,7 @@ struct ccid3_hc_tx_sock {
#define ccid3hctx_t_rto ccid3hctx_tfrc.tfrctx_rto
#define ccid3hctx_t_ipi ccid3hctx_tfrc.tfrctx_ipi
u16 ccid3hctx_s;
- u8 ccid3hctx_state;
+ enum ccid3_hc_tx_states ccid3hctx_state;
u8 ccid3hctx_last_win_count;
u8 ccid3hctx_idle;
struct timeval ccid3hctx_t_last_win_count;
@@ -115,6 +123,13 @@ struct ccid3_hc_tx_sock {
struct ccid3_options_received ccid3hctx_options_received;
};
+/* TFRC receiver states */
+enum ccid3_hc_rx_states {
+ TFRC_RSTATE_NO_DATA = 1,
+ TFRC_RSTATE_DATA,
+ TFRC_RSTATE_TERM = 127,
+};
+
struct ccid3_hc_rx_sock {
struct tfrc_rx_info ccid3hcrx_tfrc;
#define ccid3hcrx_x_recv ccid3hcrx_tfrc.tfrcrx_x_recv
@@ -122,8 +137,8 @@ struct ccid3_hc_rx_sock {
#define ccid3hcrx_p ccid3hcrx_tfrc.tfrcrx_p
u64 ccid3hcrx_seqno_nonloss:48,
ccid3hcrx_ccval_nonloss:4,
- ccid3hcrx_state:8,
ccid3hcrx_ccval_last_counter:4;
+ enum ccid3_hc_rx_states ccid3hcrx_state;
u32 ccid3hcrx_bytes_recv;
struct timeval ccid3hcrx_tstamp_last_feedback;
struct timeval ccid3hcrx_tstamp_last_ack;
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -73,14 +73,6 @@ static struct dccp_tx_hist *ccid3_tx_his
static struct dccp_rx_hist *ccid3_rx_hist;
static struct dccp_li_hist *ccid3_li_hist;
-/* TFRC sender states */
-enum ccid3_hc_tx_states {
- TFRC_SSTATE_NO_SENT = 1,
- TFRC_SSTATE_NO_FBACK,
- TFRC_SSTATE_FBACK,
- TFRC_SSTATE_TERM,
-};
-
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
{
@@ -248,11 +240,8 @@ static void ccid3_hc_tx_no_feedback_time
2 * usecs_div(hctx->ccid3hctx_s,
hctx->ccid3hctx_x));
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- goto out;
+ case TFRC_SSTATE_NO_SENT:
+ BUG(); /* can't wait for feedback without having sent */
}
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
@@ -273,7 +262,7 @@ static int ccid3_hc_tx_send_packet(struc
long delay;
int rc = -ENOTCONN;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
/* Check if pure ACK or Terminating*/
/*
@@ -326,12 +315,8 @@ static int ccid3_hc_tx_send_packet(struc
/* divide by -1000 is to convert to ms and get sign right */
rc = delay > 0 ? delay : 0;
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- rc = -EINVAL;
- break;
+ case TFRC_SSTATE_TERM:
+ BUG();
}
/* Can we send? if so add options and add to packet history */
@@ -353,7 +338,7 @@ static void ccid3_hc_tx_packet_sent(stru
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct timeval now;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
dccp_timestamp(sk, &now);
@@ -420,11 +405,8 @@ static void ccid3_hc_tx_packet_sent(stru
hctx->ccid3hctx_t_ipi);
}
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- break;
+ case TFRC_SSTATE_TERM:
+ BUG();
}
}
@@ -441,7 +423,7 @@ static void ccid3_hc_tx_packet_recv(stru
u32 x_recv;
u32 r_sample;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
/* we are only interested in ACKs */
if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
@@ -457,6 +439,7 @@ static void ccid3_hc_tx_packet_recv(stru
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_SENT:
/* FIXME: what to do here? */
+ printk(KERN_WARNING "%s: action UNIMPLEMENTED\n", __FUNCTION__);
return;
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
@@ -565,11 +548,8 @@ static void ccid3_hc_tx_packet_recv(stru
/* set idle flag */
hctx->ccid3hctx_idle = 1;
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- break;
+ case TFRC_SSTATE_TERM:
+ BUG();
}
}
@@ -686,13 +666,6 @@ static void ccid3_hc_tx_exit(struct sock
* RX Half Connection methods
*/
-/* TFRC receiver states */
-enum ccid3_hc_rx_states {
- TFRC_RSTATE_NO_DATA = 1,
- TFRC_RSTATE_DATA,
- TFRC_RSTATE_TERM = 127,
-};
-
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
{
@@ -741,11 +714,8 @@ static void ccid3_hc_rx_send_feedback(st
delta);
}
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
- return;
+ case TFRC_RSTATE_TERM:
+ BUG();
}
packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
@@ -1004,9 +974,7 @@ static void ccid3_hc_rx_packet_recv(stru
u32 p_prev, rtt_prev, r_sample, t_elapsed;
int loss;
- BUG_ON(hcrx == NULL ||
- !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
- hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
+ BUG_ON(hcrx == NULL);
opt_recv = &dccp_sk(sk)->dccps_options_received;
@@ -1085,11 +1053,8 @@ static void ccid3_hc_rx_packet_recv(stru
ccid3_hc_rx_send_feedback(sk);
}
return;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
- return;
+ case TFRC_RSTATE_TERM:
+ BUG();
}
/* Dealing with packet loss */
-
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