From 2d1c304cb2d5cf28d8362496bd9ea6aadf4f01d2 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 2 Feb 2016 14:39:09 +0100 Subject: [PATCH] cfg80211: add function for 802.3 conversion with separate output buffer Use skb_copy_bits in preparation for allowing fragmented skbs Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg --- net/wireless/util.c | 106 ++++++++++++++++++++++++++-------------------------- 1 file changed, 53 insertions(+), 53 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 6a40769..f75f601 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -393,9 +393,9 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) } EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); -unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) +static unsigned int __ieee80211_get_mesh_hdrlen(u8 flags) { - int ae = meshhdr->flags & MESH_FLAGS_AE; + int ae = flags & MESH_FLAGS_AE; /* 802.11-2012, 8.2.4.7.3 */ switch (ae) { default: @@ -407,21 +407,31 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) return 18; } } + +unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) +{ + return __ieee80211_get_mesh_hdrlen(meshhdr->flags); +} EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen); -int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, - enum nl80211_iftype iftype) +static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr, + const u8 *addr, enum nl80211_iftype iftype) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 hdrlen, ethertype; - u8 *payload; - u8 dst[ETH_ALEN]; - u8 src[ETH_ALEN] __aligned(2); + struct { + u8 hdr[ETH_ALEN] __aligned(2); + __be16 proto; + } payload; + struct ethhdr tmp; + u16 hdrlen; + u8 mesh_flags = 0; if (unlikely(!ieee80211_is_data_present(hdr->frame_control))) return -1; hdrlen = ieee80211_hdrlen(hdr->frame_control); + if (skb->len < hdrlen + 8) + return -1; /* convert IEEE 802.11 header + possible LLC headers into Ethernet * header @@ -432,8 +442,11 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, * 1 0 BSSID SA DA n/a * 1 1 RA TA DA SA */ - memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN); - memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN); + memcpy(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN); + memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN); + + if (iftype == NL80211_IFTYPE_MESH_POINT) + skb_copy_bits(skb, hdrlen, &mesh_flags, 1); switch (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { @@ -450,44 +463,31 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, iftype != NL80211_IFTYPE_STATION)) return -1; if (iftype == NL80211_IFTYPE_MESH_POINT) { - struct ieee80211s_hdr *meshdr = - (struct ieee80211s_hdr *) (skb->data + hdrlen); - /* make sure meshdr->flags is on the linear part */ - if (!pskb_may_pull(skb, hdrlen + 1)) - return -1; - if (meshdr->flags & MESH_FLAGS_AE_A4) + if (mesh_flags & MESH_FLAGS_AE_A4) return -1; - if (meshdr->flags & MESH_FLAGS_AE_A5_A6) { + if (mesh_flags & MESH_FLAGS_AE_A5_A6) { skb_copy_bits(skb, hdrlen + offsetof(struct ieee80211s_hdr, eaddr1), - dst, ETH_ALEN); - skb_copy_bits(skb, hdrlen + - offsetof(struct ieee80211s_hdr, eaddr2), - src, ETH_ALEN); + tmp.h_dest, 2 * ETH_ALEN); } - hdrlen += ieee80211_get_mesh_hdrlen(meshdr); + hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags); } break; case cpu_to_le16(IEEE80211_FCTL_FROMDS): if ((iftype != NL80211_IFTYPE_STATION && iftype != NL80211_IFTYPE_P2P_CLIENT && iftype != NL80211_IFTYPE_MESH_POINT) || - (is_multicast_ether_addr(dst) && - ether_addr_equal(src, addr))) + (is_multicast_ether_addr(tmp.h_dest) && + ether_addr_equal(tmp.h_source, addr))) return -1; if (iftype == NL80211_IFTYPE_MESH_POINT) { - struct ieee80211s_hdr *meshdr = - (struct ieee80211s_hdr *) (skb->data + hdrlen); - /* make sure meshdr->flags is on the linear part */ - if (!pskb_may_pull(skb, hdrlen + 1)) + if (mesh_flags & MESH_FLAGS_AE_A5_A6) return -1; - if (meshdr->flags & MESH_FLAGS_AE_A5_A6) - return -1; - if (meshdr->flags & MESH_FLAGS_AE_A4) + if (mesh_flags & MESH_FLAGS_AE_A4) skb_copy_bits(skb, hdrlen + offsetof(struct ieee80211s_hdr, eaddr1), - src, ETH_ALEN); - hdrlen += ieee80211_get_mesh_hdrlen(meshdr); + tmp.h_source, ETH_ALEN); + hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags); } break; case cpu_to_le16(0): @@ -498,33 +498,33 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, break; } - if (!pskb_may_pull(skb, hdrlen + 8)) - return -1; - - payload = skb->data + hdrlen; - ethertype = (payload[6] << 8) | payload[7]; + skb_copy_bits(skb, hdrlen, &payload, sizeof(payload)); + tmp.h_proto = payload.proto; - if (likely((ether_addr_equal(payload, rfc1042_header) && - ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) || - ether_addr_equal(payload, bridge_tunnel_header))) { + if (likely((ether_addr_equal(payload.hdr, rfc1042_header) && + tmp.h_proto != htons(ETH_P_AARP) && + tmp.h_proto != htons(ETH_P_IPX)) || + ether_addr_equal(payload.hdr, bridge_tunnel_header))) /* remove RFC1042 or Bridge-Tunnel encapsulation and * replace EtherType */ - skb_pull(skb, hdrlen + 6); - memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN); - memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN); - } else { - struct ethhdr *ehdr; - __be16 len; + hdrlen += ETH_ALEN + 2; + else + tmp.h_proto = htons(skb->len); + + pskb_pull(skb, hdrlen); - skb_pull(skb, hdrlen); - len = htons(skb->len); + if (!ehdr) ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr)); - memcpy(ehdr->h_dest, dst, ETH_ALEN); - memcpy(ehdr->h_source, src, ETH_ALEN); - ehdr->h_proto = len; - } + memcpy(ehdr, &tmp, sizeof(tmp)); + return 0; } + +int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, + enum nl80211_iftype iftype) +{ + return __ieee80211_data_to_8023(skb, NULL, addr, iftype); +} EXPORT_SYMBOL(ieee80211_data_to_8023); int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr, -- 2.7.4