/* * Common framework for low-level network console, dump, and debugger code * * Sep 8 2003 Matt Mackall <mpm@selenic.com> * * based on the netconsole code from: * * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> * Copyright (C) 2002 Red Hat, Inc. */ #include <linux/smp_lock.h>#include <linux/netdevice.h>#include <linux/etherdevice.h>#include <linux/string.h>#include <linux/if_arp.h>#include <linux/inetdevice.h>#include <linux/inet.h>#include <linux/interrupt.h>#include <linux/netpoll.h>#include <linux/sched.h>#include <linux/delay.h>#include <linux/rcupdate.h>#include <linux/workqueue.h>#include <net/tcp.h>#include <net/udp.h>#include <asm/unaligned.h> /* * We maintain a small pool of fully-sized skbs, to make sure the * message gets out even in extreme OOM situations. */ #define MAX_UDP_CHUNK 1460#define MAX_SKBS 32#define MAX_QUEUE_DEPTH (MAX_SKBS / 2)#define MAX_RETRIES 20000 static DEFINE_SPINLOCK(skb_list_lock);static int nr_skbs;static struct sk_buff *skbs; static DEFINE_SPINLOCK(queue_lock);static int queue_depth;static struct sk_buff *queue_head, *queue_tail; static atomic_t trapped; #define NETPOLL_RX_ENABLED 1#define NETPOLL_RX_DROP 2 #define MAX_SKB_SIZE \ (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ sizeof(struct iphdr) + sizeof(struct ethhdr)) static void zap_completion_queue(void); static void queue_process(void *p){ unsigned long flags; struct sk_buff *skb; while (queue_head) { spin_lock_irqsave(&queue_lock, flags); skb = queue_head; queue_head = skb->next; if (skb == queue_tail) queue_head = NULL; queue_depth--; spin_unlock_irqrestore(&queue_lock, flags); dev_queue_xmit(skb); }} static DECLARE_WORK(send_queue, queue_process, NULL); void netpoll_queue(struct sk_buff *skb){ unsigned long flags; if (queue_depth == MAX_QUEUE_DEPTH) { __kfree_skb(skb); return; } spin_lock_irqsave(&queue_lock, flags); if (!queue_head) queue_head = skb; else queue_tail->next = skb; queue_tail = skb; queue_depth++; spin_unlock_irqrestore(&queue_lock, flags); schedule_work(&send_queue);} static int checksum_udp(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, u32 saddr, u32 daddr){ unsigned int psum; if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) return 0; psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); if (skb->ip_summed == CHECKSUM_HW && !(u16)csum_fold(csum_add(psum, skb->csum))) return 0; skb->csum = psum; return __skb_checksum_complete(skb);} /* * Check whether delayed processing was scheduled for our NIC. If so, * we attempt to grab the poll lock and use ->poll() to pump the card. * If this fails, either we've recursed in ->poll() or it's already * running on another CPU. * * Note: we don't mask interrupts with this lock because we're using * trylock here and interrupts are already disabled in the softirq * case. Further, we test the poll_owner to avoid recursion on UP * systems where the lock doesn't exist. * * In cases where there is bi-directional communications, reading only * one message at a time can lead to packets being dropped by the * network adapter, forcing superfluous retries and possibly timeouts. * Thus, we set our budget to greater than 1. */static void poll_napi(struct netpoll *np){ struct netpoll_info *npinfo = np->dev->npinfo; int budget = 16; if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && npinfo->poll_owner != smp_processor_id() && spin_trylock(&npinfo->poll_lock)) { npinfo->rx_flags |= NETPOLL_RX_DROP; atomic_inc(&trapped); np->dev->poll(np->dev, &budget); atomic_dec(&trapped); npinfo->rx_flags &= ~NETPOLL_RX_DROP; spin_unlock(&npinfo->poll_lock); }} void netpoll_poll(struct netpoll *np){ if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) return; /* Process pending work on NIC */ np->dev->poll_controller(np->dev); if (np->dev->poll) poll_napi(np); zap_completion_queue();} static void refill_skbs(void){ struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&skb_list_lock, flags); while (nr_skbs < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break; skb->next = skbs; skbs = skb; nr_skbs++; } spin_unlock_irqrestore(&skb_list_lock, flags);} static void zap_completion_queue(void){ unsigned long flags; struct softnet_data *sd = &get_cpu_var(softnet_data); if (sd->completion_queue) { struct sk_buff *clist; local_irq_save(flags); clist = sd->completion_queue; sd->completion_queue = NULL; local_irq_restore(flags); while (clist != NULL) { struct sk_buff *skb = clist; clist = clist->next; if(skb->destructor) dev_kfree_skb_any(skb); /* put this one back */ else __kfree_skb(skb); } } put_cpu_var(softnet_data);} static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve){ int once = 1, count = 0; unsigned long flags; struct sk_buff *skb = NULL; zap_completion_queue();repeat: if (nr_skbs < MAX_SKBS) refill_skbs(); skb = alloc_skb(len, GFP_ATOMIC); if (!skb) { spin_lock_irqsave(&skb_list_lock, flags); skb = skbs; if (skb) { skbs = skb->next; skb->next = NULL; nr_skbs--; } spin_unlock_irqrestore(&skb_list_lock, flags); } if(!skb) { count++; if (once && (count == 1000000)) { printk("out of netpoll skbs!\n"); once = 0; } netpoll_poll(np); goto repeat; } atomic_set(&skb->users, 1); skb_reserve(skb, reserve); return skb;} static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb){ int status; struct netpoll_info *npinfo; if (!np || !np->dev || !netif_running(np->dev)) { __kfree_skb(skb); return; } npinfo = np->dev->npinfo; /* avoid recursion */ if (npinfo->poll_owner == smp_processor_id() || np->dev->xmit_lock_owner == smp_processor_id()) { if (np->drop) np->drop(skb); else __kfree_skb(skb); return; } do { npinfo->tries--; netif_tx_lock(np->dev); /* * network drivers do not expect to be called if the queue is * stopped. */ if (netif_queue_stopped(np->dev)) { netif_tx_unlock(np->dev); netpoll_poll(np); udelay(50); continue; } status = np->dev->hard_start_xmit(skb, np->dev); netif_tx_unlock(np->dev); /* success */ if(!status) { npinfo->tries = MAX_RETRIES; /* reset */ return; } /* transmit busy */ netpoll_poll(np); udelay(50); } while (npinfo->tries > 0);} void netpoll_send_udp(struct netpoll *np, const char *msg, int len){ int total_len, eth_len, ip_len, udp_len; struct sk_buff *skb; struct udphdr *udph; struct iphdr *iph; struct ethhdr *eth; udp_len = len + sizeof(*udph); ip_len = eth_len = udp_len + sizeof(*iph); total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; skb = find_skb(np, total_len, total_len - len); if (!skb) return; memcpy(skb->data, msg, len); skb->len += len; udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); udph->source = htons(np->local_port); udph->dest = htons(np->remote_port); udph->len = htons(udp_len); udph->check = 0; iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); /* iph->version = 4; iph->ihl = 5; */ put_unaligned(0x45, (unsigned char *)iph); iph->tos = 0; put_unaligned(htons(ip_len), &(iph->tot_len)); iph->id = 0; iph->frag_off = 0; iph->ttl = 64; iph->protocol = IPPROTO_UDP; iph->check = 0; put_unaligned(htonl(np->local_ip), &(iph->saddr)); put_unaligned(htonl(np->remote_ip), &(iph->daddr)); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); eth->h_proto = htons(ETH_P_IP); memcpy(eth->h_source, np->local_mac, 6); memcpy(eth->h_dest, np->remote_mac, 6); skb->dev = np->dev; netpoll_send_skb(np, skb);} static void arp_reply(struct sk_buff *skb){ struct netpoll_info *npinfo = skb->dev->npinfo; struct arphdr *arp; unsigned char *arp_ptr; int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; u32 sip, tip; struct sk_buff *send_skb; struct netpoll *np = NULL; if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) np = npinfo->rx_np; if (!np) return; /* No arp on this interface */ if (skb->dev->flags & IFF_NOARP) return; if (!pskb_may_pull(skb, (sizeof(struct arphdr) + (2 * skb->dev->addr_len) + (2 * sizeof(u32))))) return; skb->h.raw = skb->nh.raw = skb->data; arp = skb->nh.arph; if ((arp->ar_hrd != htons(ARPHRD_ETHER) && arp->ar_hrd != htons(ARPHRD_IEEE802)) || arp->ar_pro != htons(ETH_P_IP) || arp->ar_op != htons(ARPOP_REQUEST)) return; arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; memcpy(&sip, arp_ptr, 4); arp_ptr += 4 + skb->dev->addr_len; memcpy(&tip, arp_ptr, 4); /* Should we ignore arp? */ if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) return; size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), LL_RESERVED_SPACE(np->dev)); if (!send_skb) return; send_skb->nh.raw = send_skb->data; arp = (struct arphdr *) skb_put(send_skb, size); send_skb->dev = skb->dev; send_skb->protocol = htons(ETH_P_ARP); /* Fill the device header for the ARP frame */ if (np->dev->hard_header && np->dev->hard_header(send_skb, skb->dev, ptype, np->remote_mac, np->local_mac, send_skb->len) < 0) { kfree_skb(send_skb); return; } /* * Fill out the arp protocol part. * * we only support ethernet device type, * which (according to RFC 1390) should always equal 1 (Ethernet). */ arp->ar_hrd = htons(np->dev->type); arp->ar_pro = htons(ETH_P_IP); arp->ar_hln = np->dev->addr_len; arp->ar_pln = 4; arp->ar_op = htons(type); arp_ptr=(unsigned char *)(arp + 1); memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &tip, 4); arp_ptr += 4; memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &sip, 4); netpoll_send_skb(np, send_skb);} int __netpoll_rx(struct sk_buff *skb){ int proto, len, ulen; struct iphdr *iph; struct udphdr *uh; struct netpoll *np = skb->dev->npinfo->rx_np; if (!np) goto out; if (skb->dev->type != ARPHRD_ETHER) goto out; /* check if netpoll clients need ARP */ if (skb->protocol == __constant_htons(ETH_P_ARP) && atomic_read(&trapped)) { arp_reply(skb); return 1; } proto = ntohs(eth_hdr(skb)->h_proto); if (proto != ETH_P_IP) goto out; if (skb->pkt_type == PACKET_OTHERHOST) goto out; if (skb_shared(skb)) goto out; iph = (struct iphdr *)skb->data; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) goto out; len = ntohs(iph->tot_len); if (skb->len < len || len < iph->ihl*4) goto out; if (iph->protocol != IPPROTO_UDP) goto out; len -= iph->ihl*4; uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); ulen = ntohs(uh->len); if (ulen != len) goto out; if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) goto out; if (np->local_ip && np->local_ip != ntohl(iph->daddr)) goto out; if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) goto out; if (np->local_port && np->local_port != ntohs(uh->dest))Lines 1–500 of 788. 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/* * Common framework for low-level network console, dump, and debugger code * * Sep 8 2003 Matt Mackall <mpm@selenic.com> * * based on the netconsole code from: * * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> * Copyright (C) 2002 Red Hat, Inc. */ #include <linux/smp_lock.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/string.h> #include <linux/if_arp.h> #include <linux/inetdevice.h> #include <linux/inet.h> #include <linux/interrupt.h> #include <linux/netpoll.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/rcupdate.h> #include <linux/workqueue.h> #include <net/tcp.h> #include <net/udp.h> #include <asm/unaligned.h> /* * We maintain a small pool of fully-sized skbs, to make sure the * message gets out even in extreme OOM situations. */ #define MAX_UDP_CHUNK 1460 #define MAX_SKBS 32 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) #define MAX_RETRIES 20000 static DEFINE_SPINLOCK(skb_list_lock); static int nr_skbs; static struct sk_buff *skbs; static DEFINE_SPINLOCK(queue_lock); static int queue_depth; static struct sk_buff *queue_head, *queue_tail; static atomic_t trapped; #define NETPOLL_RX_ENABLED 1 #define NETPOLL_RX_DROP 2 #define MAX_SKB_SIZE \ (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ sizeof(struct iphdr) + sizeof(struct ethhdr)) static void zap_completion_queue(void); static void queue_process(void *p) { unsigned long flags; struct sk_buff *skb; while (queue_head) { spin_lock_irqsave(&queue_lock, flags); skb = queue_head; queue_head = skb->next; if (skb == queue_tail) queue_head = NULL; queue_depth--; spin_unlock_irqrestore(&queue_lock, flags); dev_queue_xmit(skb); } } static DECLARE_WORK(send_queue, queue_process, NULL); void netpoll_queue(struct sk_buff *skb) { unsigned long flags; if (queue_depth == MAX_QUEUE_DEPTH) { __kfree_skb(skb); return; } spin_lock_irqsave(&queue_lock, flags); if (!queue_head) queue_head = skb; else queue_tail->next = skb; queue_tail = skb; queue_depth++; spin_unlock_irqrestore(&queue_lock, flags); schedule_work(&send_queue); } static int checksum_udp(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, u32 saddr, u32 daddr) { unsigned int psum; if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) return 0; psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); if (skb->ip_summed == CHECKSUM_HW && !(u16)csum_fold(csum_add(psum, skb->csum))) return 0; skb->csum = psum; return __skb_checksum_complete(skb); } /* * Check whether delayed processing was scheduled for our NIC. If so, * we attempt to grab the poll lock and use ->poll() to pump the card. * If this fails, either we've recursed in ->poll() or it's already * running on another CPU. * * Note: we don't mask interrupts with this lock because we're using * trylock here and interrupts are already disabled in the softirq * case. Further, we test the poll_owner to avoid recursion on UP * systems where the lock doesn't exist. * * In cases where there is bi-directional communications, reading only * one message at a time can lead to packets being dropped by the * network adapter, forcing superfluous retries and possibly timeouts. * Thus, we set our budget to greater than 1. */ static void poll_napi(struct netpoll *np) { struct netpoll_info *npinfo = np->dev->npinfo; int budget = 16; if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && npinfo->poll_owner != smp_processor_id() && spin_trylock(&npinfo->poll_lock)) { npinfo->rx_flags |= NETPOLL_RX_DROP; atomic_inc(&trapped); np->dev->poll(np->dev, &budget); atomic_dec(&trapped); npinfo->rx_flags &= ~NETPOLL_RX_DROP; spin_unlock(&npinfo->poll_lock); } } void netpoll_poll(struct netpoll *np) { if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) return; /* Process pending work on NIC */ np->dev->poll_controller(np->dev); if (np->dev->poll) poll_napi(np); zap_completion_queue(); } static void refill_skbs(void) { struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&skb_list_lock, flags); while (nr_skbs < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break; skb->next = skbs; skbs = skb; nr_skbs++; } spin_unlock_irqrestore(&skb_list_lock, flags); } static void zap_completion_queue(void) { unsigned long flags; struct softnet_data *sd = &get_cpu_var(softnet_data); if (sd->completion_queue) { struct sk_buff *clist; local_irq_save(flags); clist = sd->completion_queue; sd->completion_queue = NULL; local_irq_restore(flags); while (clist != NULL) { struct sk_buff *skb = clist; clist = clist->next; if(skb->destructor) dev_kfree_skb_any(skb); /* put this one back */ else __kfree_skb(skb); } } put_cpu_var(softnet_data); } static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve) { int once = 1, count = 0; unsigned long flags; struct sk_buff *skb = NULL; zap_completion_queue(); repeat: if (nr_skbs < MAX_SKBS) refill_skbs(); skb = alloc_skb(len, GFP_ATOMIC); if (!skb) { spin_lock_irqsave(&skb_list_lock, flags); skb = skbs; if (skb) { skbs = skb->next; skb->next = NULL; nr_skbs--; } spin_unlock_irqrestore(&skb_list_lock, flags); } if(!skb) { count++; if (once && (count == 1000000)) { printk("out of netpoll skbs!\n"); once = 0; } netpoll_poll(np); goto repeat; } atomic_set(&skb->users, 1); skb_reserve(skb, reserve); return skb; } static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) { int status; struct netpoll_info *npinfo; if (!np || !np->dev || !netif_running(np->dev)) { __kfree_skb(skb); return; } npinfo = np->dev->npinfo; /* avoid recursion */ if (npinfo->poll_owner == smp_processor_id() || np->dev->xmit_lock_owner == smp_processor_id()) { if (np->drop) np->drop(skb); else __kfree_skb(skb); return; } do { npinfo->tries--; netif_tx_lock(np->dev); /* * network drivers do not expect to be called if the queue is * stopped. */ if (netif_queue_stopped(np->dev)) { netif_tx_unlock(np->dev); netpoll_poll(np); udelay(50); continue; } status = np->dev->hard_start_xmit(skb, np->dev); netif_tx_unlock(np->dev); /* success */ if(!status) { npinfo->tries = MAX_RETRIES; /* reset */ return; } /* transmit busy */ netpoll_poll(np); udelay(50); } while (npinfo->tries > 0); } void netpoll_send_udp(struct netpoll *np, const char *msg, int len) { int total_len, eth_len, ip_len, udp_len; struct sk_buff *skb; struct udphdr *udph; struct iphdr *iph; struct ethhdr *eth; udp_len = len + sizeof(*udph); ip_len = eth_len = udp_len + sizeof(*iph); total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; skb = find_skb(np, total_len, total_len - len); if (!skb) return; memcpy(skb->data, msg, len); skb->len += len; udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); udph->source = htons(np->local_port); udph->dest = htons(np->remote_port); udph->len = htons(udp_len); udph->check = 0; iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); /* iph->version = 4; iph->ihl = 5; */ put_unaligned(0x45, (unsigned char *)iph); iph->tos = 0; put_unaligned(htons(ip_len), &(iph->tot_len)); iph->id = 0; iph->frag_off = 0; iph->ttl = 64; iph->protocol = IPPROTO_UDP; iph->check = 0; put_unaligned(htonl(np->local_ip), &(iph->saddr)); put_unaligned(htonl(np->remote_ip), &(iph->daddr)); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); eth->h_proto = htons(ETH_P_IP); memcpy(eth->h_source, np->local_mac, 6); memcpy(eth->h_dest, np->remote_mac, 6); skb->dev = np->dev; netpoll_send_skb(np, skb); } static void arp_reply(struct sk_buff *skb) { struct netpoll_info *npinfo = skb->dev->npinfo; struct arphdr *arp; unsigned char *arp_ptr; int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; u32 sip, tip; struct sk_buff *send_skb; struct netpoll *np = NULL; if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) np = npinfo->rx_np; if (!np) return; /* No arp on this interface */ if (skb->dev->flags & IFF_NOARP) return; if (!pskb_may_pull(skb, (sizeof(struct arphdr) + (2 * skb->dev->addr_len) + (2 * sizeof(u32))))) return; skb->h.raw = skb->nh.raw = skb->data; arp = skb->nh.arph; if ((arp->ar_hrd != htons(ARPHRD_ETHER) && arp->ar_hrd != htons(ARPHRD_IEEE802)) || arp->ar_pro != htons(ETH_P_IP) || arp->ar_op != htons(ARPOP_REQUEST)) return; arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; memcpy(&sip, arp_ptr, 4); arp_ptr += 4 + skb->dev->addr_len; memcpy(&tip, arp_ptr, 4); /* Should we ignore arp? */ if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) return; size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), LL_RESERVED_SPACE(np->dev)); if (!send_skb) return; send_skb->nh.raw = send_skb->data; arp = (struct arphdr *) skb_put(send_skb, size); send_skb->dev = skb->dev; send_skb->protocol = htons(ETH_P_ARP); /* Fill the device header for the ARP frame */ if (np->dev->hard_header && np->dev->hard_header(send_skb, skb->dev, ptype, np->remote_mac, np->local_mac, send_skb->len) < 0) { kfree_skb(send_skb); return; } /* * Fill out the arp protocol part. * * we only support ethernet device type, * which (according to RFC 1390) should always equal 1 (Ethernet). */ arp->ar_hrd = htons(np->dev->type); arp->ar_pro = htons(ETH_P_IP); arp->ar_hln = np->dev->addr_len; arp->ar_pln = 4; arp->ar_op = htons(type); arp_ptr=(unsigned char *)(arp + 1); memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &tip, 4); arp_ptr += 4; memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &sip, 4); netpoll_send_skb(np, send_skb); } int __netpoll_rx(struct sk_buff *skb) { int proto, len, ulen; struct iphdr *iph; struct udphdr *uh; struct netpoll *np = skb->dev->npinfo->rx_np; if (!np) goto out; if (skb->dev->type != ARPHRD_ETHER) goto out; /* check if netpoll clients need ARP */ if (skb->protocol == __constant_htons(ETH_P_ARP) && atomic_read(&trapped)) { arp_reply(skb); return 1; } proto = ntohs(eth_hdr(skb)->h_proto); if (proto != ETH_P_IP) goto out; if (skb->pkt_type == PACKET_OTHERHOST) goto out; if (skb_shared(skb)) goto out; iph = (struct iphdr *)skb->data; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) goto out; len = ntohs(iph->tot_len); if (skb->len < len || len < iph->ihl*4) goto out; if (iph->protocol != IPPROTO_UDP) goto out; len -= iph->ihl*4; uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); ulen = ntohs(uh->len); if (ulen != len) goto out; if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) goto out; if (np->local_ip && np->local_ip != ntohl(iph->daddr)) goto out; if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) goto out; if (np->local_port && np->local_port != ntohs(uh->dest))