[B.A.T.M.A.N.] [PATCH v2] batman-adv: Record route for ICMP messages

Daniel Seither
2010-02-15T15:28:51Z

The standard layer 3 ping utility can use the record route (RR) 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 adds a second batman ICMP packet format (icmp_packet_rr) such
that up to 17 MAC addresses can be recorded (sufficient for up to 8
hops per direction). When no RR is wanted, the old icmp_packet without
the RR overhead can be sent.

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.

Signed-off-by: Daniel Seither <post@tiwoc.de>
---
Index: batman-adv-kernelland/types.h
===================================================================
--- batman-adv-kernelland/types.h (revision 1573)
+++ batman-adv-kernelland/types.h (working copy)
@@ -106,7 +106,7 @@

struct device_packet {
struct list_head list;
- struct icmp_packet icmp_packet;
+ struct icmp_packet_rr icmp_packet;
};

struct hna_local_entry {
Index: batman-adv-kernelland/packet.h
===================================================================
--- batman-adv-kernelland/packet.h (revision 1573)
+++ batman-adv-kernelland/packet.h (working copy)
@@ -26,6 +26,7 @@
#define BAT_UNICAST 0x03
#define BAT_BCAST 0x04
#define BAT_VIS 0x05
+#define BAT_ICMP_RR 0x06

/* this file is included by batctl which needs these defines */
#define COMPAT_VERSION 9
@@ -71,6 +72,23 @@
uint8_t uid;
} __attribute__((packed));

+#define BAT_RR_LEN 96
+
+/* icmp_packet_rr must start with all fields from imcp_packet
+ as this is assumed by code that handles ICMP packets */
+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));
+
struct unicast_packet {
uint8_t packet_type;
uint8_t version; /* batman version field */
Index: batman-adv-kernelland/device.c
===================================================================
--- batman-adv-kernelland/device.c (revision 1573)
+++ batman-adv-kernelland/device.c (working copy)
@@ -165,6 +165,7 @@
struct device_packet *device_packet;
int error;
unsigned long flags;
+ size_t packet_len = sizeof(struct icmp_packet);

if ((file->f_flags & O_NONBLOCK) && (device_client->queue_len == 0))
return -EAGAIN;
@@ -190,15 +191,18 @@

spin_unlock_irqrestore(&device_client->lock, flags);

+ if (device_packet->icmp_packet.packet_type == BAT_ICMP_RR)
+ packet_len = sizeof(struct icmp_packet_rr);
+
error = __copy_to_user(buf, &device_packet->icmp_packet,
- sizeof(struct icmp_packet));
+ packet_len);

kfree(device_packet);

if (error)
return error;

- return sizeof(struct icmp_packet);
+ return packet_len;
}

ssize_t bat_device_write(struct file *file, const char __user *buff,
@@ -206,28 +210,42 @@
{
struct device_client *device_client =
(struct device_client *)file->private_data;
- struct icmp_packet icmp_packet;
+ struct icmp_packet_rr icmp_packet;
struct orig_node *orig_node;
struct batman_if *batman_if;
uint8_t dstaddr[ETH_ALEN];
unsigned long flags;
+ size_t packet_len = sizeof(struct icmp_packet);
+ int with_rr = 0;

if (len < sizeof(struct icmp_packet)) {
bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: invalid packet size\n");
return -EINVAL;
}

- if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet)))
+ if (len >= sizeof(struct icmp_packet_rr)) {
+ with_rr = 1;
+ packet_len = sizeof(struct icmp_packet_rr);
+ }
+
+ if (!access_ok(VERIFY_READ, buff, packet_len))
return -EFAULT;

- if (__copy_from_user(&icmp_packet, buff, sizeof(icmp_packet)))
+ if (__copy_from_user(&icmp_packet, buff, packet_len))
return -EFAULT;

- if (icmp_packet.packet_type != BAT_ICMP) {
- bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
+ if (icmp_packet.packet_type != BAT_ICMP
+ && icmp_packet.packet_type != BAT_ICMP_RR) {
+ bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP or BAT_ICMP_RR)\n");
return -EINVAL;
}

+ if (!with_rr && icmp_packet.packet_type == BAT_ICMP_RR) {
+ bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from "
+ "char device: invalid packet size for BAT_ICMP_RR\n");
+ return -EINVAL;
+ }
+
if (icmp_packet.msg_type != ECHO_REQUEST) {
bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: got bogus message type (expected: ECHO_REQUEST)\n");
return -EINVAL;
@@ -269,8 +287,14 @@
batman_if->net_dev->dev_addr,
ETH_ALEN);

+ if (with_rr) {
+ memcpy(icmp_packet.rr,
+ batman_if->net_dev->dev_addr,
+ ETH_ALEN);
+ }
+
send_raw_packet((unsigned char *)&icmp_packet,
- sizeof(struct icmp_packet),
+ packet_len,
batman_if, dstaddr);

goto out;
@@ -298,11 +322,15 @@
}

void bat_device_add_packet(struct device_client *device_client,
- struct icmp_packet *icmp_packet)
+ struct icmp_packet_rr *icmp_packet)
{
struct device_packet *device_packet;
unsigned long flags;
+ size_t packet_len = sizeof(struct icmp_packet);

+ if (icmp_packet->packet_type == BAT_ICMP_RR)
+ packet_len = sizeof(struct icmp_packet_rr);
+
device_packet = kmalloc(sizeof(struct device_packet), GFP_KERNEL);

if (!device_packet)
@@ -310,7 +338,7 @@

INIT_LIST_HEAD(&device_packet->list);
memcpy(&device_packet->icmp_packet, icmp_packet,
- sizeof(struct icmp_packet));
+ packet_len);

spin_lock_irqsave(&device_client->lock, flags);

@@ -339,7 +367,7 @@
wake_up(&device_client->queue_wait);
}

-void bat_device_receive_packet(struct icmp_packet *icmp_packet)
+void bat_device_receive_packet(struct icmp_packet_rr *icmp_packet)
{
struct device_client *hash = device_client_hash[icmp_packet->uid];

Index: batman-adv-kernelland/device.h
===================================================================
--- batman-adv-kernelland/device.h (revision 1573)
+++ batman-adv-kernelland/device.h (working copy)
@@ -32,5 +32,5 @@
size_t len, loff_t *off);
unsigned int bat_device_poll(struct file *file, poll_table *wait);
void bat_device_add_packet(struct device_client *device_client,
- struct icmp_packet *icmp_packet);
-void bat_device_receive_packet(struct icmp_packet *icmp_packet);
+ struct icmp_packet_rr *icmp_packet);
+void bat_device_receive_packet(struct icmp_packet_rr *icmp_packet);
Index: batman-adv-kernelland/hard-interface.c
===================================================================
--- batman-adv-kernelland/hard-interface.c (revision 1573)
+++ batman-adv-kernelland/hard-interface.c (working copy)
@@ -479,6 +479,7 @@

/* batman icmp packet */
case BAT_ICMP:
+ case BAT_ICMP_RR:
ret = recv_icmp_packet(skb);
break;

Index: batman-adv-kernelland/routing.c
===================================================================
--- batman-adv-kernelland/routing.c (revision 1573)
+++ batman-adv-kernelland/routing.c (working copy)
@@ -709,15 +709,16 @@
static int recv_my_icmp_packet(struct sk_buff *skb)
{
struct orig_node *orig_node;
- struct icmp_packet *icmp_packet;
+ struct icmp_packet_rr *icmp_packet;
struct ethhdr *ethhdr;
struct sk_buff *skb_old;
struct batman_if *batman_if;
int ret;
unsigned long flags;
uint8_t dstaddr[ETH_ALEN];
+ int packet_len = sizeof(struct icmp_packet);

- icmp_packet = (struct icmp_packet *) skb->data;
+ icmp_packet = (struct icmp_packet_rr *) skb->data;
ethhdr = (struct ethhdr *) skb_mac_header(skb);

/* add data to device queue */
@@ -726,6 +727,9 @@
return NET_RX_DROP;
}

+ if (icmp_packet->packet_type == BAT_ICMP_RR)
+ packet_len = sizeof(struct icmp_packet_rr);
+
/* answer echo request (ping) */
/* get routing information */
spin_lock_irqsave(&orig_hash_lock, flags);
@@ -745,12 +749,12 @@

/* create a copy of the skb, if needed, to modify it. */
skb_old = NULL;
- if (!skb_clone_writable(skb, sizeof(struct icmp_packet))) {
+ if (!skb_clone_writable(skb, packet_len)) {
skb_old = skb;
skb = skb_copy(skb, GFP_ATOMIC);
if (!skb)
return NET_RX_DROP;
- icmp_packet = (struct icmp_packet *) skb->data;
+ icmp_packet = (struct icmp_packet_rr *) skb->data;
kfree_skb(skb_old);
}

@@ -778,6 +782,7 @@
int ret;
unsigned long flags;
uint8_t dstaddr[ETH_ALEN];
+ int len = sizeof(struct icmp_packet);

icmp_packet = (struct icmp_packet *)skb->data;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
@@ -789,6 +794,9 @@
return NET_RX_DROP;
}

+ if (icmp_packet->packet_type == BAT_ICMP_RR)
+ len = sizeof(struct icmp_packet_rr);
+
/* get routing information */
spin_lock_irqsave(&orig_hash_lock, flags);
orig_node = ((struct orig_node *)
@@ -806,7 +814,7 @@
spin_unlock_irqrestore(&orig_hash_lock, flags);

/* create a copy of the skb, if needed, to modify it. */
- if (!skb_clone_writable(skb, sizeof(struct icmp_packet))) {
+ if (!skb_clone_writable(skb, len)) {
skb_old = skb;
skb = skb_copy(skb, GFP_ATOMIC);
if (!skb)
@@ -832,7 +840,7 @@

int recv_icmp_packet(struct sk_buff *skb)
{
- struct icmp_packet *icmp_packet;
+ struct icmp_packet_rr *icmp_packet;
struct ethhdr *ethhdr;
struct orig_node *orig_node;
struct sk_buff *skb_old;
@@ -860,8 +868,24 @@
if (!is_my_mac(ethhdr->h_dest))
return NET_RX_DROP;

- icmp_packet = (struct icmp_packet *) skb->data;
+ icmp_packet = (struct icmp_packet_rr *) skb->data;

+ if (icmp_packet->packet_type == BAT_ICMP_RR) {
+ hdr_size = sizeof(struct icmp_packet_rr);
+
+ /* drop packet if it has not necessary minimum size */
+ if (skb_headlen(skb) < hdr_size)
+ return NET_RX_DROP;
+
+ /* add record route information if not full */
+ if (icmp_packet->rr_cur > 0
+ && 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);
@@ -888,12 +912,12 @@
spin_unlock_irqrestore(&orig_hash_lock, flags);

/* create a copy of the skb, if needed, to modify it. */
- if (!skb_clone_writable(skb, sizeof(struct icmp_packet))) {
+ if (!skb_clone_writable(skb, hdr_size)) {
skb_old = skb;
skb = skb_copy(skb, GFP_ATOMIC);
if (!skb)
return NET_RX_DROP;
- icmp_packet = (struct icmp_packet *) skb->data;
+ icmp_packet = (struct icmp_packet_rr *) skb->data;
kfree_skb(skb_old);
}

Index: batctl/ping.c
===================================================================
--- batctl/ping.c (revision 1573)
+++ batctl/ping.c (working copy)
@@ -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)
@@ -64,20 +65,22 @@

int ping(int argc, char **argv)
{
- struct icmp_packet icmp_packet_out, icmp_packet_in;
+ struct icmp_packet_rr 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];
+ size_t packet_len;

- while ((optchar = getopt(argc, argv, "hc:i:t:")) != -1) {
+ while ((optchar = getopt(argc, argv, "hc:i:t:R")) != -1) {
switch (optchar) {
case 'c':
loop_count = strtol(optarg, NULL , 10);
@@ -100,6 +103,10 @@
timeout = 1;
found_args += ((*((char*)(optarg - 1)) == optchar ) ? 1 : 2);
break;
+ case 'R':
+ rr = 1;
+ found_args++;
+ break;
default:
ping_usage();
return EXIT_FAILURE;
@@ -141,6 +148,8 @@
goto out;
}

+ packet_len = sizeof(struct icmp_packet);
+
memcpy(&icmp_packet_out.dst, dst_mac, ETH_ALEN);
icmp_packet_out.packet_type = BAT_ICMP;
icmp_packet_out.version = COMPAT_VERSION;
@@ -148,8 +157,15 @@
icmp_packet_out.ttl = 50;
icmp_packet_out.seqno = 0;

+ if (rr) {
+ icmp_packet_out.packet_type = BAT_ICMP_RR;
+ packet_len = sizeof(struct icmp_packet_rr);
+ icmp_packet_out.rr_cur = 1;
+ 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);
+ packet_len, packet_len + 28);

while (!is_aborted) {
if (loop_count == 0)
@@ -160,7 +176,7 @@

icmp_packet_out.seqno = htons(++seq_counter);

- if (write(ping_fd, (char *)&icmp_packet_out, sizeof(icmp_packet_out)) < 0) {
+ if (write(ping_fd, (char *)&icmp_packet_out, packet_len) < 0) {
printf("Error - can't write to batman adv kernel file '%s': %s\n", BAT_DEVICE, strerror(errno));
goto sleep;
}
@@ -188,26 +204,55 @@
if (res < 0)
goto sleep;

- read_len = read(ping_fd, (char *)&icmp_packet_in, sizeof(icmp_packet_in));
+ read_len = read(ping_fd, (char *)&icmp_packet_in, packet_len);

if (read_len < 0) {
printf("Error - can't read from batman adv kernel file '%s': %s\n", BAT_DEVICE, strerror(errno));
goto sleep;
}

- if ((size_t)read_len < sizeof(icmp_packet_in)) {
+ if ((size_t)read_len < packet_len) {
printf("Warning - dropping received packet as it is smaller than expected (%zu): %zd\n",
- sizeof(icmp_packet_in), read_len);
+ packet_len, read_len);
goto sleep;
}

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.packet_type == BAT_ICMP_RR) {
+ 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)