From: Ilpo Järvinen Date: Tue, 16 Dec 2008 09:15:11 +0000 (-0800) Subject: ipmr: merge common code X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b1879204dda06a92a4ff55b681c99ee185180003;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git ipmr: merge common code Also removes redundant skb->len < x check which can't be true once pskb_may_pull(skb, x) succeeded. $ diff-funcs pim_rcv ipmr.c ipmr.c pim_rcv_v1 --- ipmr.c:pim_rcv() +++ ipmr.c:pim_rcv_v1() @@ -1,22 +1,27 @@ -static int pim_rcv(struct sk_buff * skb) +int pim_rcv_v1(struct sk_buff * skb) { - struct pimreghdr *pim; + struct igmphdr *pim; struct iphdr *encap; struct net_device *reg_dev = NULL; if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) goto drop; - pim = (struct pimreghdr *)skb_transport_header(skb); - if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) || - (pim->flags&PIM_NULL_REGISTER) || - (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 && - csum_fold(skb_checksum(skb, 0, skb->len, 0)))) + pim = igmp_hdr(skb); + + if (!mroute_do_pim || + skb->len < sizeof(*pim) + sizeof(*encap) || + pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) goto drop; - /* check if the inner packet is destined to mcast group */ encap = (struct iphdr *)(skb_transport_header(skb) + - sizeof(struct pimreghdr)); + sizeof(struct igmphdr)); + /* + Check that: + a. packet is really destinted to a multicast group + b. packet is not a NULL-REGISTER + c. packet is not truncated + */ if (!ipv4_is_multicast(encap->daddr) || encap->tot_len == 0 || ntohs(encap->tot_len) + sizeof(*pim) > skb->len) @@ -40,9 +45,9 @@ skb->ip_summed = 0; skb->pkt_type = PACKET_HOST; dst_release(skb->dst); + skb->dst = NULL; reg_dev->stats.rx_bytes += skb->len; reg_dev->stats.rx_packets++; - skb->dst = NULL; nf_reset(skb); netif_rx(skb); dev_put(reg_dev); $ codiff net/ipv4/ipmr.o.old net/ipv4/ipmr.o.new net/ipv4/ipmr.c: pim_rcv_v1 | -283 pim_rcv | -284 2 functions changed, 567 bytes removed net/ipv4/ipmr.c: __pim_rcv | +307 1 function changed, 307 bytes added net/ipv4/ipmr.o.new: 3 functions changed, 307 bytes added, 567 bytes removed, diff: -260 (Tested on x86_64). It seems that pimlen arg could be left out as well and eq-sizedness of structs trapped with BUILD_BUG_ON but I don't think that's more than a cosmetic flaw since there aren't that many args anyway. Compile tested. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 244a624e0b1..14666449dc1 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1482,29 +1482,13 @@ dont_forward: return 0; } -#ifdef CONFIG_IP_PIMSM_V1 -/* - * Handle IGMP messages of PIMv1 - */ - -int pim_rcv_v1(struct sk_buff * skb) +#ifdef CONFIG_IP_PIMSM +static int __pim_rcv(struct sk_buff *skb, unsigned int pimlen) { - struct igmphdr *pim; - struct iphdr *encap; - struct net_device *reg_dev = NULL; - - if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) - goto drop; + struct net_device *reg_dev = NULL; + struct iphdr *encap; - pim = igmp_hdr(skb); - - if (!mroute_do_pim || - skb->len < sizeof(*pim) + sizeof(*encap) || - pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) - goto drop; - - encap = (struct iphdr *)(skb_transport_header(skb) + - sizeof(struct igmphdr)); + encap = (struct iphdr *)(skb_transport_header(skb) + pimlen); /* Check that: a. packet is really destinted to a multicast group @@ -1513,8 +1497,8 @@ int pim_rcv_v1(struct sk_buff * skb) */ if (!ipv4_is_multicast(encap->daddr) || encap->tot_len == 0 || - ntohs(encap->tot_len) + sizeof(*pim) > skb->len) - goto drop; + ntohs(encap->tot_len) + pimlen > skb->len) + return 1; read_lock(&mrt_lock); if (reg_vif_num >= 0) @@ -1524,7 +1508,7 @@ int pim_rcv_v1(struct sk_buff * skb) read_unlock(&mrt_lock); if (reg_dev == NULL) - goto drop; + return 1; skb->mac_header = skb->network_header; skb_pull(skb, (u8*)encap - skb->data); @@ -1540,9 +1524,33 @@ int pim_rcv_v1(struct sk_buff * skb) nf_reset(skb); netif_rx(skb); dev_put(reg_dev); + return 0; - drop: - kfree_skb(skb); +} +#endif + +#ifdef CONFIG_IP_PIMSM_V1 +/* + * Handle IGMP messages of PIMv1 + */ + +int pim_rcv_v1(struct sk_buff * skb) +{ + struct igmphdr *pim; + + if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) + goto drop; + + pim = igmp_hdr(skb); + + if (!mroute_do_pim || + pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) + goto drop; + + if (__pim_rcv(skb, sizeof(*pim))) { +drop: + kfree_skb(skb); + } return 0; } #endif @@ -1551,10 +1559,8 @@ int pim_rcv_v1(struct sk_buff * skb) static int pim_rcv(struct sk_buff * skb) { struct pimreghdr *pim; - struct iphdr *encap; - struct net_device *reg_dev = NULL; - if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) + if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) goto drop; pim = (struct pimreghdr *)skb_transport_header(skb); @@ -1564,41 +1570,10 @@ static int pim_rcv(struct sk_buff * skb) csum_fold(skb_checksum(skb, 0, skb->len, 0)))) goto drop; - /* check if the inner packet is destined to mcast group */ - encap = (struct iphdr *)(skb_transport_header(skb) + - sizeof(struct pimreghdr)); - if (!ipv4_is_multicast(encap->daddr) || - encap->tot_len == 0 || - ntohs(encap->tot_len) + sizeof(*pim) > skb->len) - goto drop; - - read_lock(&mrt_lock); - if (reg_vif_num >= 0) - reg_dev = vif_table[reg_vif_num].dev; - if (reg_dev) - dev_hold(reg_dev); - read_unlock(&mrt_lock); - - if (reg_dev == NULL) - goto drop; - - skb->mac_header = skb->network_header; - skb_pull(skb, (u8*)encap - skb->data); - skb_reset_network_header(skb); - skb->dev = reg_dev; - skb->protocol = htons(ETH_P_IP); - skb->ip_summed = 0; - skb->pkt_type = PACKET_HOST; - dst_release(skb->dst); - reg_dev->stats.rx_bytes += skb->len; - reg_dev->stats.rx_packets++; - skb->dst = NULL; - nf_reset(skb); - netif_rx(skb); - dev_put(reg_dev); - return 0; - drop: - kfree_skb(skb); + if (__pim_rcv(skb, sizeof(*pim))) { +drop: + kfree_skb(skb); + } return 0; } #endif