diff options
| -rw-r--r-- | net/batman-adv/distributed-arp-table.c | 4 | ||||
| -rw-r--r-- | net/batman-adv/gateway_client.c | 171 | ||||
| -rw-r--r-- | net/batman-adv/gateway_client.h | 4 | ||||
| -rw-r--r-- | net/batman-adv/send.c | 16 | ||||
| -rw-r--r-- | net/batman-adv/send.h | 10 | ||||
| -rw-r--r-- | net/batman-adv/soft-interface.c | 76 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 12 |
7 files changed, 153 insertions, 140 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 93e1fb0..997ae6a 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -1037,9 +1037,9 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, BATADV_P_DAT_CACHE_REPLY, - vid); + NULL, vid); else - err = batadv_send_skb_via_tt(bat_priv, skb_new, vid); + err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); if (err != NET_XMIT_DROP) { batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index a5602ef..4150a64 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -28,11 +28,17 @@ #include <linux/udp.h> #include <linux/if_vlan.h> -/* This is the offset of the options field in a dhcp packet starting at - * the beginning of the dhcp header +/* These are the offsets of the "hw type" and "hw address length" in the dhcp + * packet starting at the beginning of the dhcp header */ -#define BATADV_DHCP_OPTIONS_OFFSET 240 -#define BATADV_DHCP_REQUEST 3 +#define BATADV_DHCP_HTYPE_OFFSET 1 +#define BATADV_DHCP_HLEN_OFFSET 2 +/* Value of htype representing Ethernet */ +#define BATADV_DHCP_HTYPE_ETHERNET 0x01 +/* This is the offset of the "chaddr" field in the dhcp packet starting at the + * beginning of the dhcp header + */ +#define BATADV_DHCP_CHADDR_OFFSET 28 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) { @@ -596,80 +602,39 @@ out: return 0; } -/* this call might reallocate skb data */ -static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len) -{ - int ret = false; - unsigned char *p; - int pkt_len; - - if (skb_linearize(skb) < 0) - goto out; - - pkt_len = skb_headlen(skb); - - if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1) - goto out; - - p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET; - pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1; - - /* Access the dhcp option lists. Each entry is made up by: - * - octet 1: option type - * - octet 2: option data len (only if type != 255 and 0) - * - octet 3: option data - */ - while (*p != 255 && !ret) { - /* p now points to the first octet: option type */ - if (*p == 53) { - /* type 53 is the message type option. - * Jump the len octet and go to the data octet - */ - if (pkt_len < 2) - goto out; - p += 2; - - /* check if the message type is what we need */ - if (*p == BATADV_DHCP_REQUEST) - ret = true; - break; - } else if (*p == 0) { - /* option type 0 (padding), just go forward */ - if (pkt_len < 1) - goto out; - pkt_len--; - p++; - } else { - /* This is any other option. So we get the length... */ - if (pkt_len < 1) - goto out; - pkt_len--; - p++; - - /* ...and then we jump over the data */ - if (pkt_len < 1 + (*p)) - goto out; - pkt_len -= 1 + (*p); - p += 1 + (*p); - } - } -out: - return ret; -} - -/* this call might reallocate skb data */ -bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) +/** + * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message + * @skb: the packet to check + * @header_len: a pointer to the batman-adv header size + * @chaddr: buffer where the client address will be stored. Valid + * only if the function returns BATADV_DHCP_TO_CLIENT + * + * Returns: + * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error + * while parsing it + * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server + * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client + * + * This function may re-allocate the data buffer of the skb passed as argument. + */ +enum batadv_dhcp_recipient +batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len, + uint8_t *chaddr) { + enum batadv_dhcp_recipient ret = BATADV_DHCP_NO; struct ethhdr *ethhdr; struct iphdr *iphdr; struct ipv6hdr *ipv6hdr; struct udphdr *udphdr; struct vlan_ethhdr *vhdr; + int chaddr_offset; __be16 proto; + uint8_t *p; /* check for ethernet header */ if (!pskb_may_pull(skb, *header_len + ETH_HLEN)) - return false; + return BATADV_DHCP_NO; + ethhdr = (struct ethhdr *)skb->data; proto = ethhdr->h_proto; *header_len += ETH_HLEN; @@ -677,7 +642,7 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) /* check for initial vlan header */ if (proto == htons(ETH_P_8021Q)) { if (!pskb_may_pull(skb, *header_len + VLAN_HLEN)) - return false; + return BATADV_DHCP_NO; vhdr = (struct vlan_ethhdr *)skb->data; proto = vhdr->h_vlan_encapsulated_proto; @@ -688,32 +653,34 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) switch (proto) { case htons(ETH_P_IP): if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr))) - return false; + return BATADV_DHCP_NO; + iphdr = (struct iphdr *)(skb->data + *header_len); *header_len += iphdr->ihl * 4; /* check for udp header */ if (iphdr->protocol != IPPROTO_UDP) - return false; + return BATADV_DHCP_NO; break; case htons(ETH_P_IPV6): if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr))) - return false; + return BATADV_DHCP_NO; + ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len); *header_len += sizeof(*ipv6hdr); /* check for udp header */ if (ipv6hdr->nexthdr != IPPROTO_UDP) - return false; + return BATADV_DHCP_NO; break; default: - return false; + return BATADV_DHCP_NO; } if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr))) - return false; + return BATADV_DHCP_NO; /* skb->data might have been reallocated by pskb_may_pull() */ ethhdr = (struct ethhdr *)skb->data; @@ -724,17 +691,40 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) *header_len += sizeof(*udphdr); /* check for bootp port */ - if ((proto == htons(ETH_P_IP)) && - (udphdr->dest != htons(67))) - return false; + switch (proto) { + case htons(ETH_P_IP): + if (udphdr->dest == htons(67)) + ret = BATADV_DHCP_TO_SERVER; + else if (udphdr->source == htons(67)) + ret = BATADV_DHCP_TO_CLIENT; + break; + case htons(ETH_P_IPV6): + if (udphdr->dest == htons(547)) + ret = BATADV_DHCP_TO_SERVER; + else if (udphdr->source == htons(547)) + ret = BATADV_DHCP_TO_CLIENT; + break; + } - if ((proto == htons(ETH_P_IPV6)) && - (udphdr->dest != htons(547))) - return false; + chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET; + /* store the client address if the message is going to a client */ + if (ret == BATADV_DHCP_TO_CLIENT && + pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) { + /* check if the DHCP packet carries an Ethernet DHCP */ + p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET; + if (*p != BATADV_DHCP_HTYPE_ETHERNET) + return BATADV_DHCP_NO; + + /* check if the DHCP packet carries a valid Ethernet address */ + p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET; + if (*p != ETH_ALEN) + return BATADV_DHCP_NO; + + memcpy(chaddr, skb->data + chaddr_offset, ETH_ALEN); + } - return true; + return ret; } - /** * batadv_gw_out_of_range - check if the dhcp request destination is the best gw * @bat_priv: the bat priv with all the soft interface information @@ -748,6 +738,7 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len) * false otherwise. * * This call might reallocate skb data. + * Must be invoked only when the DHCP packet is going TO a DHCP SERVER. */ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, struct sk_buff *skb) @@ -755,19 +746,13 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL; struct batadv_orig_node *orig_dst_node = NULL; struct batadv_gw_node *gw_node = NULL, *curr_gw = NULL; - struct ethhdr *ethhdr; - bool ret, out_of_range = false; - unsigned int header_len = 0; + struct ethhdr *ethhdr = (struct ethhdr *)skb->data; + bool out_of_range = false; uint8_t curr_tq_avg; unsigned short vid; vid = batadv_get_vid(skb, 0); - ret = batadv_gw_is_dhcp_target(skb, &header_len); - if (!ret) - goto out; - - ethhdr = (struct ethhdr *)skb->data; orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source, ethhdr->h_dest, vid); if (!orig_dst_node) @@ -777,10 +762,6 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, if (!gw_node->bandwidth_down == 0) goto out; - ret = batadv_is_type_dhcprequest(skb, header_len); - if (!ret) - goto out; - switch (atomic_read(&bat_priv->gw_mode)) { case BATADV_GW_MODE_SERVER: /* If we are a GW then we are our best GW. We can artificially diff --git a/net/batman-adv/gateway_client.h b/net/batman-adv/gateway_client.h index 514cff6..006befb 100644 --- a/net/batman-adv/gateway_client.h +++ b/net/batman-adv/gateway_client.h @@ -32,7 +32,9 @@ void batadv_gw_node_delete(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node); void batadv_gw_node_purge(struct batadv_priv *bat_priv); int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset); -bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len); bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, struct sk_buff *skb); +enum batadv_dhcp_recipient +batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len, + uint8_t *chaddr); #endif /* _NET_BATMAN_ADV_GATEWAY_CLIENT_H_ */ diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index cea6578..30d12c4 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -319,13 +319,23 @@ out: */ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, struct sk_buff *skb, int packet_type, - int packet_subtype, unsigned short vid) + int packet_subtype, uint8_t *dst_hint, + unsigned short vid) { struct ethhdr *ethhdr = (struct ethhdr *)skb->data; struct batadv_orig_node *orig_node; + uint8_t *src, *dst; + + src = ethhdr->h_source; + dst = ethhdr->h_dest; + + /* if we got an hint! let's send the packet to this client (if any) */ + if (dst_hint) { + src = NULL; + dst = dst_hint; + } + orig_node = batadv_transtable_search(bat_priv, src, dst, vid); - orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source, - ethhdr->h_dest, vid); return batadv_send_skb_unicast(bat_priv, skb, packet_type, packet_subtype, orig_node, vid); } diff --git a/net/batman-adv/send.h b/net/batman-adv/send.h index f6d125e..0b17f8d 100644 --- a/net/batman-adv/send.h +++ b/net/batman-adv/send.h @@ -38,7 +38,8 @@ bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv, int packet_subtype); int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, struct sk_buff *skb, int packet_type, - int packet_subtype, unsigned short vid); + int packet_subtype, uint8_t *dst_hint, + unsigned short vid); int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid); @@ -55,11 +56,11 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. */ static inline int batadv_send_skb_via_tt(struct batadv_priv *bat_priv, - struct sk_buff *skb, + struct sk_buff *skb, uint8_t *dst_hint, unsigned short vid) { return batadv_send_skb_via_tt_generic(bat_priv, skb, BATADV_UNICAST, 0, - vid); + dst_hint, vid); } /** @@ -79,11 +80,12 @@ static inline int batadv_send_skb_via_tt(struct batadv_priv *bat_priv, static inline int batadv_send_skb_via_tt_4addr(struct batadv_priv *bat_priv, struct sk_buff *skb, int packet_subtype, + uint8_t *dst_hint, unsigned short vid) { return batadv_send_skb_via_tt_generic(bat_priv, skb, BATADV_UNICAST_4ADDR, - packet_subtype, vid); + packet_subtype, dst_hint, vid); } #endif /* _NET_BATMAN_ADV_SEND_H_ */ diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 3686be7..b569932 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -160,6 +160,8 @@ static int batadv_interface_tx(struct sk_buff *skb, 0x00, 0x00}; static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00, 0x00, 0x00}; + enum batadv_dhcp_recipient dhcp_rcp = BATADV_DHCP_NO; + uint8_t *dst_hint = NULL, chaddr[ETH_ALEN]; struct vlan_ethhdr *vhdr; unsigned int header_len = 0; int data_len = skb->len, ret; @@ -167,6 +169,7 @@ static int batadv_interface_tx(struct sk_buff *skb, bool do_bcast = false, client_added; unsigned short vid; uint32_t seqno; + int gw_mode; if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; @@ -213,36 +216,39 @@ static int batadv_interface_tx(struct sk_buff *skb, if (batadv_compare_eth(ethhdr->h_dest, ectp_addr)) goto dropped; + gw_mode = atomic_read(&bat_priv->gw_mode); if (is_multicast_ether_addr(ethhdr->h_dest)) { - do_bcast = true; - - switch (atomic_read(&bat_priv->gw_mode)) { - case BATADV_GW_MODE_SERVER: - /* gateway servers should not send dhcp - * requests into the mesh - */ - ret = batadv_gw_is_dhcp_target(skb, &header_len); - if (ret) - goto dropped; - break; - case BATADV_GW_MODE_CLIENT: - /* gateway clients should send dhcp requests - * via unicast to their gateway - */ - ret = batadv_gw_is_dhcp_target(skb, &header_len); - if (ret) - do_bcast = false; - break; - case BATADV_GW_MODE_OFF: - default: - break; + /* if gw mode is off, broadcast every packet */ + if (gw_mode == BATADV_GW_MODE_OFF) { + do_bcast = true; + goto send; } - /* reminder: ethhdr might have become unusable from here on - * (batadv_gw_is_dhcp_target() might have reallocated skb data) + dhcp_rcp = batadv_gw_dhcp_recipient_get(skb, &header_len, + chaddr); + /* skb->data may have been modified by + * batadv_gw_dhcp_recipient_get() */ + ethhdr = (struct ethhdr *)skb->data; + /* if gw_mode is on, broadcast any non-DHCP message. + * All the DHCP packets are going to be sent as unicast + */ + if (dhcp_rcp == BATADV_DHCP_NO) { + do_bcast = true; + goto send; + } + + if (dhcp_rcp == BATADV_DHCP_TO_CLIENT) + dst_hint = chaddr; + else if ((gw_mode == BATADV_GW_MODE_SERVER) && + (dhcp_rcp == BATADV_DHCP_TO_SERVER)) + /* gateways should not forward any DHCP message if + * directed to a DHCP server + */ + goto dropped; } +send: batadv_skb_set_priority(skb, 0); /* ethernet packet should be broadcasted */ @@ -288,22 +294,22 @@ static int batadv_interface_tx(struct sk_buff *skb, /* unicast packet */ } else { - if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) { + /* DHCP packets going to a server will use the GW feature */ + if (dhcp_rcp == BATADV_DHCP_TO_SERVER) { ret = batadv_gw_out_of_range(bat_priv, skb); if (ret) goto dropped; - } - - if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb)) - goto dropped; - - batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb); - - if (is_multicast_ether_addr(ethhdr->h_dest)) ret = batadv_send_skb_via_gw(bat_priv, skb, vid); - else - ret = batadv_send_skb_via_tt(bat_priv, skb, vid); + } else { + if (batadv_dat_snoop_outgoing_arp_request(bat_priv, + skb)) + goto dropped; + batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb); + + ret = batadv_send_skb_via_tt(bat_priv, skb, dst_hint, + vid); + } if (ret == NET_XMIT_DROP) goto dropped_freed; } diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index e545ac97..70abb1c 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -34,6 +34,18 @@ #endif /* CONFIG_BATMAN_ADV_DAT */ /** + * enum batadv_dhcp_recipient - dhcp destination + * @BATADV_DHCP_NO: packet is not a dhcp message + * @BATADV_DHCP_TO_SERVER: dhcp message is directed to a server + * @BATADV_DHCP_TO_CLIENT: dhcp message is directed to a client + */ +enum batadv_dhcp_recipient { + BATADV_DHCP_NO = 0, + BATADV_DHCP_TO_SERVER, + BATADV_DHCP_TO_CLIENT, +}; + +/** * BATADV_TT_REMOTE_MASK - bitmask selecting the flags that are sent over the * wire only */ |
