batman-adv: Record route for ICMP messages
Commit Message
The standard layer 3 ping utility can use the record route option of IP
to collect route data for sent ping messages (ping -R). This patch
introduces comparable functionality for batman-adv ICMP messages.
The patch modifies the batman ICMP packet format such that up to 17 MAC
addresses can be recorded (sufficient for up to 8 hops per direction).
batctl is extended to recognize the -R option for the ping subcommand.
The output should be the same as for the standard iputils ping program.
For this, the destination host is printed two times.
In device.c, the sender's MAC address is inserted at the first position
when receiving a ping message from batctl and RR is enabled (rr_cur >
0). In routing.c, each forwarding node then appends its own MAC address.
This patch could be improved by dynamically growing the packet when a
MAC address is to be added to the recorded route instead of statically
allocating a buffer of fixed length.
Signed-off-by: Daniel Seither <post@tiwoc.de>
---
loop_count = strtol(optarg, NULL , 10);
@@ -100,6 +102,10 @@
timeout = 1;
found_args += ((*((char*)(optarg - 1)) == optchar ) ? 1 : 2);
break;
+ case 'R':
+ rr = 1;
+ found_args++;
+ break;
default:
ping_usage();
return EXIT_FAILURE;
@@ -147,6 +153,8 @@
icmp_packet_out.msg_type = ECHO_REQUEST;
icmp_packet_out.ttl = 50;
icmp_packet_out.seqno = 0;
+ icmp_packet_out.rr_cur = (rr) ? 1 : 0;
+ memset(&icmp_packet_out.rr, 0, BAT_RR_LEN);
printf("PING %s (%s) %zu(%zu) bytes of data\n", dst_string, mac_string,
sizeof(icmp_packet_out), sizeof(icmp_packet_out) + 28);
@@ -204,10 +212,34 @@
switch (icmp_packet_in.msg_type) {
case ECHO_REPLY:
time_delta = end_timer();
- printf("%zd bytes from %s icmp_seq=%hu ttl=%d time=%.2f ms\n",
+ printf("%zd bytes from %s icmp_seq=%hu ttl=%d time=%.2f ms",
read_len, dst_string, ntohs(icmp_packet_in.seqno),
icmp_packet_in.ttl, time_delta);
+ if (icmp_packet_in.rr_cur) {
+ if (last_rr_cur == icmp_packet_in.rr_cur && !memcmp(last_rr,
icmp_packet_in.rr, BAT_RR_LEN)) {
+ printf("\t(same route)\n");
+ } else {
+ printf("\nRR: ");
+ for (i = 0; i < BAT_RR_LEN/ETH_ALEN && i < icmp_packet_in.rr_cur;
i++) {
+ rr_mac = (struct ether_addr *)&icmp_packet_in.rr[i*ETH_ALEN];
+ rr_host = bat_hosts_find_by_mac((char *)rr_mac);
+ if (rr_host)
+ rr_string = rr_host->name;
+ else
+ rr_string = ether_ntoa_long(rr_mac);
+ printf("\t%s\n", rr_string);
+ if (memcmp(rr_mac, dst_mac, ETH_ALEN) == 0)
+ printf("\t%s\n", rr_string);
+ }
+ printf("\n");
+
+ last_rr_cur = icmp_packet_in.rr_cur;
+ memcpy(last_rr, icmp_packet_in.rr, BAT_RR_LEN);
+ }
+ } else
+ printf("\n");
+
if ((time_delta < min) || (min == 0.0))
min = time_delta;
if (time_delta > max)
Comments
On Saturday 13 February 2010 02:35:19 Daniel Seither wrote:
> The standard layer 3 ping utility can use the record route option of IP
> to collect route data for sent ping messages (ping -R). This patch
> introduces comparable functionality for batman-adv ICMP messages.
>
> The patch modifies the batman ICMP packet format such that up to 17 MAC
> addresses can be recorded (sufficient for up to 8 hops per direction).
> batctl is extended to recognize the -R option for the ping subcommand.
> The output should be the same as for the standard iputils ping program.
> For this, the destination host is printed two times.
This is a very cool patch! I know quite some people will be happy to see this
functionality. :-)
> This patch could be improved by dynamically growing the packet when a
> MAC address is to be added to the recorded route instead of statically
> allocating a buffer of fixed length.
I don't think it will be necessary to change the packet size dynamically. The
gain will be rather small compared to the overhead it creates. However, it
would make sense to specify 2 different icmp structs and only send the large
packet when RR is really needed.
For example:
struct icmp_packet {
uint8_t packet_type;
uint8_t version; /* batman version field */
uint8_t msg_type; /* see ICMP message types above */
uint8_t ttl;
uint8_t dst[6];
uint8_t orig[6];
uint16_t seqno;
uint8_t uid;
} __attribute__((packed));
struct icmp_packet_rr {
uint8_t packet_type;
uint8_t version; /* batman version field */
uint8_t msg_type; /* see ICMP message types above */
uint8_t ttl;
uint8_t dst[6];
uint8_t orig[6];
uint16_t seqno;
uint8_t uid;
uint8_t rr_cur;
uint8_t rr[BAT_RR_LEN];
} __attribute__((packed));
What do you think?
> + /* add record route information if not full */
> + if (icmp_packet->rr_cur && icmp_packet->rr_cur < BAT_RR_LEN / ETH_ALEN) {
> + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur * ETH_ALEN]),
> ethhdr->h_dest, ETH_ALEN);
> + icmp_packet->rr_cur++;
> + }
It would be better to check for the actual packet size rather than the
BAT_RR_LEN define. Some node might have sent us an icmp packet which had a
different size and then we crash here (or worse).
Regards,
Marek
Marek Lindner schrieb:
> I don't think it will be necessary to change the packet size dynamically. The
> gain will be rather small compared to the overhead it creates. However, it
> would make sense to specify 2 different icmp structs and only send the large
> packet when RR is really needed.
Sounds good, I'll prepare a new version of the patch.
>> + /* add record route information if not full */
>> + if (icmp_packet->rr_cur && icmp_packet->rr_cur < BAT_RR_LEN / ETH_ALEN) {
>> + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur * ETH_ALEN]),
>> ethhdr->h_dest, ETH_ALEN);
>> + icmp_packet->rr_cur++;
>> + }
>
> It would be better to check for the actual packet size rather than the
> BAT_RR_LEN define. Some node might have sent us an icmp packet which had a
> different size and then we crash here (or worse).
You're right, I'll change this.
Regards, Daniel
I just sent an improved patch.
Marek Lindner schrieb:
>> + /* add record route information if not full */
>> + if (icmp_packet->rr_cur && icmp_packet->rr_cur < BAT_RR_LEN / ETH_ALEN) {
>> + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur * ETH_ALEN]),
>> ethhdr->h_dest, ETH_ALEN);
>> + icmp_packet->rr_cur++;
>> + }
>
> It would be better to check for the actual packet size rather than the
> BAT_RR_LEN define. Some node might have sent us an icmp packet which had a
> different size and then we crash here (or worse).
This should not be the case because, preliminary to adding RR info, it
is checked whether the received frame is long enough for the given
packet_type (at least in the current version of the patch).
Regards, Daniel
===================================================================
@@ -60,6 +60,8 @@
#define BAT_PACKET_LEN sizeof(struct batman_packet)
+#define BAT_RR_LEN 96
+
struct icmp_packet {
uint8_t packet_type;
uint8_t version; /* batman version field */
@@ -69,6 +71,8 @@
uint8_t orig[6];
uint16_t seqno;
uint8_t uid;
+ uint8_t rr_cur;
+ uint8_t rr[BAT_RR_LEN];
} __attribute__((packed));
struct unicast_packet {
===================================================================
@@ -268,6 +268,12 @@
memcpy(icmp_packet.orig,
batman_if->net_dev->dev_addr,
ETH_ALEN);
+
+ if (icmp_packet.rr_cur) {
+ memcpy(icmp_packet.rr,
+ batman_if->net_dev->dev_addr,
+ ETH_ALEN);
+ }
send_raw_packet((unsigned char *)&icmp_packet,
sizeof(struct icmp_packet),
===================================================================
@@ -862,6 +862,12 @@
icmp_packet = (struct icmp_packet *) skb->data;
+ /* add record route information if not full */
+ if (icmp_packet->rr_cur && icmp_packet->rr_cur < BAT_RR_LEN / ETH_ALEN) {
+ memcpy(&(icmp_packet->rr[icmp_packet->rr_cur * ETH_ALEN]),
ethhdr->h_dest, ETH_ALEN);
+ icmp_packet->rr_cur++;
+ }
+
/* packet for me */
if (is_my_mac(icmp_packet->dst))
return recv_my_icmp_packet(skb);
===================================================================
@@ -48,6 +48,7 @@
printf(" \t -h print this help\n");
printf(" \t -i interval in seconds\n");
printf(" \t -t timeout in seconds\n");
+ printf(" \t -R record route\n");
}
void sig_handler(int sig)
@@ -66,18 +67,19 @@
{
struct icmp_packet icmp_packet_out, icmp_packet_in;
struct timeval tv;
- struct ether_addr *dst_mac = NULL;
- struct bat_host *bat_host;
+ struct ether_addr *dst_mac = NULL, *rr_mac = NULL;
+ struct bat_host *bat_host, *rr_host;
ssize_t read_len;
fd_set read_socket;
int ret = EXIT_FAILURE, ping_fd = 0, res, optchar, found_args = 1;
- int loop_count = -1, loop_interval = 1, timeout = 1;
+ int loop_count = -1, loop_interval = 1, timeout = 1, rr = 0, i;
unsigned int seq_counter = 0, packets_out = 0, packets_in = 0,
packets_loss;
- char *dst_string, *mac_string;
+ char *dst_string, *mac_string, *rr_string;
double time_delta;
float min = 0.0, max = 0.0, avg = 0.0;
+ uint8_t last_rr_cur = 0, last_rr[BAT_RR_LEN];
- while ((optchar = getopt(argc, argv, "hc:i:t:")) != -1) {
+ while ((optchar = getopt(argc, argv, "hc:i:t:R")) != -1) {
switch (optchar) {
case 'c':