[B.A.T.M.A.N.] [PATCH v3] batman-adv: Record route for ICMP messages

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 16 + +/* 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][ETH_ALEN]; +} __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 +868,23 @@ 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 < BAT_RR_LEN) { + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]), + 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 +911,12 @@ 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][ETH_ALEN]; + 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 * ETH_ALEN); + } + 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 * ETH_ALEN)) { + + printf("\t(same route)\n"); + + } else { + printf("\nRR: "); + for (i = 0; i < BAT_RR_LEN + && i < icmp_packet_in.rr_cur; i++) { + + rr_mac = (struct ether_addr *)&icmp_packet_in.rr[i]; + 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 * ETH_ALEN); + } + } else + printf("\n"); + if ((time_delta < min) || (min == 0.0)) min = time_delta; if (time_delta > max)