Hello.
On 16/12/16 08:30, wsn.iot.xwq@xxxxxxxxxxxxxx wrote:
From: Xue Wenqian <wsn.iot.xwq@xxxxxxxxxxxxxx>
Hi,
Let me make some explanations for the patch:
No need to start the commit message like a mail. Just the description is
fine. :)
1. The filtering for client is made by checking frame header and sequence number
Sequence we did before as well so the additional check is for the header
here.
2. Also, when client receives the incorrect frame, it will update new timeout value and receive again until correct frame is received or timeout
What happens when a frame is really lost?
3. The filtering for server is made by just checking frame header
Guess that should help a bit to protect against 6LoWPAN traffic, but for
every other protocol setting the not a 6LoWPAN header this will not
work. Nothing we can do against though.
4. For code reuse, I replace sleeping() with get_interval() function
Signed-off-by: Xue Wenqian <wsn.iot.xwq@xxxxxxxxxxxxxx>
---
wpan-ping/wpan-ping.c | 86 ++++++++++++++++++++++++++++++-------------------
1 file changed, 53 insertions(+), 33 deletions(-)
diff --git a/wpan-ping/wpan-ping.c b/wpan-ping/wpan-ping.c
index e6df2b4..15a2a4b 100644
--- a/wpan-ping/wpan-ping.c
+++ b/wpan-ping/wpan-ping.c
@@ -235,28 +235,30 @@ static int print_address(char *addr, uint8_t dst_extended[IEEE802154_ADDR_LEN])
return 0;
}
-static void sleeping(struct timeval ping_start_time, struct timeval timeout) {
- struct timeval curr_time;
- long sec, usec, interval_usec, timeout_usec;
- long sleep_usec = 0;
- gettimeofday(&curr_time, NULL);
- sec = curr_time.tv_sec - ping_start_time.tv_sec;
- usec = curr_time.tv_usec - ping_start_time.tv_usec;
- if (usec < 0) {
- usec += 1000000;
- sec--;
+/* time interval computation */
+static long get_interval(struct timeval start_time, struct timeval end_time, long timeout_usec) {
+ long sec, usec, usecs, interval_usec = 0;
+ sec = end_time.tv_sec - start_time.tv_sec;
+ usec = end_time.tv_usec - start_time.tv_usec;
+ usecs = sec * 1000000 + usec;
+ if (usecs < timeout_usec) {
+ interval_usec = timeout_usec - usecs;
}
- interval_usec = sec * 1000000 + usec;
- timeout_usec = timeout.tv_sec * 1000000 + timeout.tv_usec;
- if (interval_usec < timeout_usec) {
- sleep_usec = timeout_usec - interval_usec;
- usleep(sleep_usec);
+ return interval_usec;
+}
+
+/* recv timeout setting */
+static void set_so_rcvtimeo(int sd, struct timeval timeout) {
+ int ret;
+ ret = setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, (struct timeval *)&timeout, sizeof(struct timeval));
+ if (ret < 0) {
+ perror("setsockopt receive timeout");
}
}
static int measure_roundtrip(struct config *conf, int sd) {
unsigned char *buf;
- struct timeval ping_start_time, start_time, end_time, timeout;
+ struct timeval ping_start_time, start_time, end_time, ping_end_time, timeout, new_timeout;
long sec = 0, usec = 0;
long sec_max = 0, usec_max = 0;
long sec_min = 2147483647, usec_min = 2147483647;
@@ -266,6 +268,8 @@ static int measure_roundtrip(struct config *conf, int sd) {
float rtt_min = 0.0, rtt_avg = 0.0, rtt_max = 0.0;
float packet_loss = 100.0;
char addr[24];
+ long timeout_usec, interval_usec, sleep_usec;
+ int set_so_rcvtimeo_flag;
if (conf->extended)
print_address(addr, conf->dst.addr.hwaddr);
@@ -287,10 +291,9 @@ static int measure_roundtrip(struct config *conf, int sd) {
timeout.tv_sec = 0;
timeout.tv_usec = conf->interval * 1000;
}
- ret = setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, (struct timeval *)&timeout,sizeof(struct timeval));
- if (ret < 0) {
- perror("setsockopt receive timeout");
- }
+ timeout_usec = conf->interval * 1000;
+ set_so_rcvtimeo(sd, timeout);
+ set_so_rcvtimeo_flag = 1;
count = 0;
for (i = 0; i < conf->packets; i++) {
@@ -302,13 +305,24 @@ static int measure_roundtrip(struct config *conf, int sd) {
perror("sendto");
}
gettimeofday(&start_time, NULL);
- ret = recv(sd, buf, conf->packet_len, 0);
- if (seq_num != ((buf[2] << 8)| buf[3])) {
- printf("Sequenze number did not match\n");
- continue;
+ while(1) {
+ ret = recv(sd, buf, conf->packet_len, 0);
+ gettimeofday(&end_time, NULL);
+ interval_usec = get_interval(ping_start_time, end_time, timeout_usec);
+ if (interval_usec > 0 && (buf[0] != '\000' || seq_num != ((buf[2] << 8)| buf[3]))) {
The header check could be buf[0] != NOT_A_6LOWPAN_FRAME
That way it is clearer what we are checking on.
+ fprintf(stderr, "Packet %i: Sequence number did not match, receive again!\n", i);
+ new_timeout.tv_sec = (int)(interval_usec * 1.0 / 1000000);
+ new_timeout.tv_usec = interval_usec - (new_timeout.tv_sec * 1000000);
+ set_so_rcvtimeo(sd, new_timeout);
+ set_so_rcvtimeo_flag = 0;
+ } else {
+ if (set_so_rcvtimeo_flag == 0) {
+ set_so_rcvtimeo(sd, timeout);
+ }
+ break;
+ }
}
if (ret > 0) {
- gettimeofday(&end_time, NULL);
count++;
sec = end_time.tv_sec - start_time.tv_sec;
sum_sec += sec;
@@ -338,9 +352,13 @@ static int measure_roundtrip(struct config *conf, int sd) {
fprintf(stdout, "%i bytes from 0x%04x seq=%i time=%.1f ms\n", ret,
conf->dst.addr.short_addr, (int)seq_num, (float)usec/1000);
} else
- fprintf(stderr, "Hit %i ms packet timeout\n", conf->interval);
+ fprintf(stderr, "Packet %i: Hit %i ms packet timeout\n", i, conf->interval);
/* sleeping */
- sleeping(ping_start_time, timeout);
+ gettimeofday(&ping_end_time, NULL);
+ sleep_usec = get_interval(ping_start_time, ping_end_time, timeout_usec);
+ if (sleep_usec > 0) {
+ usleep(sleep_usec);
+ }
}
if (count)
@@ -386,11 +404,13 @@ static void init_server(int sd) {
#if DEBUG
dump_packet(buf, len);
#endif
- /* Send same packet back */
- len = sendto(sd, buf, len, 0, (struct sockaddr *)&src, addrlen);
- if (len < 0) {
- perror("sendto");
- continue;
+ if (buf[0] == '\000') {
Something like if(buf[0] == NOT_A_6LOWPAN_FRAME) would be clearer.
+ /* Send same packet back */
+ len = sendto(sd, buf, len, 0, (struct sockaddr *)&src, addrlen);
+ if (len < 0) {
+ perror("sendto");
+ continue;
+ }
}
}
free(buf);
@@ -559,4 +579,4 @@ int main(int argc, char *argv[]) {
init_network(conf);
free(conf);
return 0;
-}
+}
What is this change? Some extra whitespace?
regards
Stefan Schmidt
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