[B.A.T.M.A.N.] [PATCH 1/2] 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.

Signed-off-by: Daniel Seither post@tiwoc.de Signed-off-by: Marek Lindner lindner_marek@yahoo.de --- batman-adv-kernelland/device.c | 42 ++++++++++++++++++++++--------------- batman-adv-kernelland/device.h | 6 +++- batman-adv-kernelland/packet.h | 17 +++++++++++++++ batman-adv-kernelland/routing.c | 44 +++++++++++++++++++++++++------------- batman-adv-kernelland/types.h | 3 +- 5 files changed, 77 insertions(+), 35 deletions(-)

diff --git a/batman-adv-kernelland/device.c b/batman-adv-kernelland/device.c index df51f1c..0c3c0b3 100644 --- a/batman-adv-kernelland/device.c +++ b/batman-adv-kernelland/device.c @@ -163,6 +163,7 @@ ssize_t bat_device_read(struct file *file, char __user *buf, size_t count, struct device_client *device_client = (struct device_client *)file->private_data; struct device_packet *device_packet; + size_t packet_len; int error; unsigned long flags;

@@ -191,14 +192,15 @@ ssize_t bat_device_read(struct file *file, char __user *buf, size_t count, spin_unlock_irqrestore(&device_client->lock, flags);

error = __copy_to_user(buf, &device_packet->icmp_packet, - sizeof(struct icmp_packet)); + device_packet->icmp_len);

+ packet_len = device_packet->icmp_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, @@ -206,9 +208,10 @@ ssize_t bat_device_write(struct file *file, const char __user *buff, { 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; + size_t packet_len = sizeof(struct icmp_packet); uint8_t dstaddr[ETH_ALEN]; unsigned long flags;

@@ -217,10 +220,13 @@ ssize_t bat_device_write(struct file *file, const char __user *buff, return -EINVAL; }

- if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet))) + if (len >= sizeof(struct icmp_packet_rr)) + 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) { @@ -238,7 +244,7 @@ ssize_t bat_device_write(struct file *file, const char __user *buff, if (icmp_packet.version != COMPAT_VERSION) { icmp_packet.msg_type = PARAMETER_PROBLEM; icmp_packet.ttl = COMPAT_VERSION; - bat_device_add_packet(device_client, &icmp_packet); + bat_device_add_packet(device_client, &icmp_packet, packet_len); goto out; }

@@ -265,13 +271,13 @@ ssize_t bat_device_write(struct file *file, const char __user *buff, if (batman_if->if_active != IF_ACTIVE) goto dst_unreach;

- memcpy(icmp_packet.orig, - batman_if->net_dev->dev_addr, - ETH_ALEN); + memcpy(icmp_packet.orig, batman_if->net_dev->dev_addr, ETH_ALEN); + + if (packet_len == sizeof(struct icmp_packet_rr)) + memcpy(icmp_packet.rr, batman_if->net_dev->dev_addr, ETH_ALEN);

send_raw_packet((unsigned char *)&icmp_packet, - sizeof(struct icmp_packet), - batman_if, dstaddr); + packet_len, batman_if, dstaddr);

goto out;

@@ -279,7 +285,7 @@ unlock: spin_unlock_irqrestore(&orig_hash_lock, flags); dst_unreach: icmp_packet.msg_type = DESTINATION_UNREACHABLE; - bat_device_add_packet(device_client, &icmp_packet); + bat_device_add_packet(device_client, &icmp_packet, packet_len); out: return len; } @@ -298,7 +304,8 @@ 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) + struct icmp_packet_rr *icmp_packet, + size_t icmp_len) { struct device_packet *device_packet; unsigned long flags; @@ -309,8 +316,8 @@ void bat_device_add_packet(struct device_client *device_client, return;

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

spin_lock_irqsave(&device_client->lock, flags);

@@ -339,10 +346,11 @@ void bat_device_add_packet(struct device_client *device_client, 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, + size_t icmp_len) { struct device_client *hash = device_client_hash[icmp_packet->uid];

if (hash) - bat_device_add_packet(hash, icmp_packet); + bat_device_add_packet(hash, icmp_packet, icmp_len); } diff --git a/batman-adv-kernelland/device.h b/batman-adv-kernelland/device.h index 46c0f44..7a9394b 100644 --- a/batman-adv-kernelland/device.h +++ b/batman-adv-kernelland/device.h @@ -32,5 +32,7 @@ ssize_t bat_device_write(struct file *file, const char __user *buff, 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, + size_t icmp_len); +void bat_device_receive_packet(struct icmp_packet_rr *icmp_packet, + size_t icmp_len); diff --git a/batman-adv-kernelland/packet.h b/batman-adv-kernelland/packet.h index 1c8e6c8..c8b973f 100644 --- a/batman-adv-kernelland/packet.h +++ b/batman-adv-kernelland/packet.h @@ -71,6 +71,23 @@ struct icmp_packet { 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 */ diff --git a/batman-adv-kernelland/routing.c b/batman-adv-kernelland/routing.c index a3adc7f..47d5757 100644 --- a/batman-adv-kernelland/routing.c +++ b/batman-adv-kernelland/routing.c @@ -706,10 +706,10 @@ int recv_bat_packet(struct sk_buff *skb, return NET_RX_SUCCESS; }

-static int recv_my_icmp_packet(struct sk_buff *skb) +static int recv_my_icmp_packet(struct sk_buff *skb, size_t icmp_len) { 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; @@ -717,12 +717,12 @@ static int recv_my_icmp_packet(struct sk_buff *skb) unsigned long flags; uint8_t dstaddr[ETH_ALEN];

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

/* add data to device queue */ if (icmp_packet->msg_type != ECHO_REQUEST) { - bat_device_receive_packet(icmp_packet); + bat_device_receive_packet(icmp_packet, icmp_len); return NET_RX_DROP; }

@@ -745,12 +745,12 @@ static int recv_my_icmp_packet(struct sk_buff *skb)

/* 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, icmp_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); }

@@ -768,7 +768,7 @@ static int recv_my_icmp_packet(struct sk_buff *skb) return ret; }

-static int recv_icmp_ttl_exceeded(struct sk_buff *skb) +static int recv_icmp_ttl_exceeded(struct sk_buff *skb, size_t icmp_len) { struct orig_node *orig_node; struct icmp_packet *icmp_packet; @@ -806,7 +806,7 @@ static int recv_icmp_ttl_exceeded(struct sk_buff *skb) 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, icmp_len)) { skb_old = skb; skb = skb_copy(skb, GFP_ATOMIC); if (!skb) @@ -832,7 +832,7 @@ static int recv_icmp_ttl_exceeded(struct sk_buff *skb)

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; @@ -842,6 +842,12 @@ int recv_icmp_packet(struct sk_buff *skb) unsigned long flags; uint8_t dstaddr[ETH_ALEN];

+ /** + * we truncate all incoming icmp packets if they don't match our size + */ + if (skb_headlen(skb) >= sizeof(struct icmp_packet_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; @@ -860,15 +866,23 @@ int recv_icmp_packet(struct sk_buff *skb) 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; + + /* add record route information if not full */ + if ((hdr_size == sizeof(struct icmp_packet_rr)) && + (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); + return recv_my_icmp_packet(skb, hdr_size);

/* TTL exceeded */ if (icmp_packet->ttl < 2) - return recv_icmp_ttl_exceeded(skb); + return recv_icmp_ttl_exceeded(skb, hdr_size);

ret = NET_RX_DROP;

@@ -888,12 +902,12 @@ int recv_icmp_packet(struct sk_buff *skb) 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); }

diff --git a/batman-adv-kernelland/types.h b/batman-adv-kernelland/types.h index d9cb5d1..a82b52d 100644 --- a/batman-adv-kernelland/types.h +++ b/batman-adv-kernelland/types.h @@ -106,7 +106,8 @@ struct device_client {

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

struct hna_local_entry {