/* * Common framework for low-level network console, dump, and debugger code * * Sep 8 2003 Matt Mackall * * based on the netconsole code from: * * Copyright (C) 2001 Ingo Molnar * Copyright (C) 2002 Red Hat, Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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 static struct sk_buff_head skb_pool; static atomic_t trapped; DEFINE_STATIC_SRCU(netpoll_srcu); #define USEC_PER_POLL 50 #define NETPOLL_RX_ENABLED 1 #define NETPOLL_RX_DROP 2 #define MAX_SKB_SIZE \ (sizeof(struct ethhdr) + \ sizeof(struct iphdr) + \ sizeof(struct udphdr) + \ MAX_UDP_CHUNK) static void zap_completion_queue(void); static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo); static void netpoll_async_cleanup(struct work_struct *work); static unsigned int carrier_timeout = 4; module_param(carrier_timeout, uint, 0644); #define np_info(np, fmt, ...) \ pr_info("%s: " fmt, np->name, ##__VA_ARGS__) #define np_err(np, fmt, ...) \ pr_err("%s: " fmt, np->name, ##__VA_ARGS__) #define np_notice(np, fmt, ...) \ pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) static void queue_process(struct work_struct *work) { struct netpoll_info *npinfo = container_of(work, struct netpoll_info, tx_work.work); struct sk_buff *skb; unsigned long flags; while ((skb = skb_dequeue(&npinfo->txq))) { struct net_device *dev = skb->dev; const struct net_device_ops *ops = dev->netdev_ops; struct netdev_queue *txq; if (!netif_device_present(dev) || !netif_running(dev)) { __kfree_skb(skb); continue; } txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); local_irq_save(flags); __netif_tx_lock(txq, smp_processor_id()); if (netif_xmit_frozen_or_stopped(txq) || ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { skb_queue_head(&npinfo->txq, skb); __netif_tx_unlock(txq); local_irq_restore(flags); schedule_delayed_work(&npinfo->tx_work, HZ/10); return; } __netif_tx_unlock(txq); local_irq_restore(flags); } } static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, __be32 saddr, __be32 daddr) { __wsum psum; if (uh->check == 0 || skb_csum_unnecessary(skb)) return 0; psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); if (skb->ip_summed == CHECKSUM_COMPLETE && !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 int poll_one_napi(struct netpoll_info *npinfo, struct napi_struct *napi, int budget) { int work; /* net_rx_action's ->poll() invocations and our's are * synchronized by this test which is only made while * holding the napi->poll_lock. */ if (!test_bit(NAPI_STATE_SCHED, &napi->state)) return budget; npinfo->rx_flags |= NETPOLL_RX_DROP; atomic_inc(&trapped); set_bit(NAPI_STATE_NPSVC, &napi->state); work = napi->poll(napi, budget); trace_napi_poll(napi); clear_bit(NAPI_STATE_NPSVC, &napi->state); atomic_dec(&trapped); npinfo->rx_flags &= ~NETPOLL_RX_DROP; return budget - work; } static void poll_napi(struct net_device *dev) { struct napi_struct *napi; int budget = 16; list_for_each_entry(napi, &dev->napi_list, dev_list) { if (napi->poll_owner != smp_processor_id() && spin_trylock(&napi->poll_lock)) { budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), napi, budget); spin_unlock(&napi->poll_lock); if (!budget) break; } } } static void service_neigh_queue(struct netpoll_info *npi) { if (npi) { struct sk_buff *skb; while ((skb = skb_dequeue(&npi->neigh_tx))) netpoll_neigh_reply(skb, npi); } } static void netpoll_poll_dev(struct net_device *dev) { const struct net_device_ops *ops; struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); /* Don't do any rx activity if the dev_lock mutex is held * the dev_open/close paths use this to block netpoll activity * while changing device state */ if (down_trylock(&ni->dev_lock)) return; if (!netif_running(dev)) { up(&ni->dev_lock); return; } ops = dev->netdev_ops; if (!ops->ndo_poll_controller) { up(&ni->dev_lock); return; } /* Process pending work on NIC */ ops->ndo_poll_controller(dev); poll_napi(dev); up(&ni->dev_lock); if (dev->flags & IFF_SLAVE) { if (ni) { struct net_device *bond_dev; struct sk_buff *skb; struct netpoll_info *bond_ni; bond_dev = netdev_master_upper_dev_get_rcu(dev); bond_ni = rcu_dereference_bh(bond_dev->npinfo); while ((skb = skb_dequeue(&ni->neigh_tx))) { skb->dev = bond_dev; skb_queue_tail(&bond_ni->neigh_tx, skb); } } } service_neigh_queue(ni); zap_completion_queue(); } void netpoll_rx_disable(struct net_device *dev) { struct netpoll_info *ni; int idx; might_sleep(); idx = srcu_read_lock(&netpoll_srcu); ni = srcu_dereference(dev->npinfo, &netpoll_srcu); if (ni) down(&ni->dev_lock); srcu_read_unlock(&netpoll_srcu, idx); } EXPORT_SYMBOL(netpoll_rx_disable); void netpoll_rx_enable(struct net_device *dev) { struct netpoll_info *ni; rcu_read_lock(); ni = rcu_dereference(dev->npinfo); if (ni) up(&ni->dev_lock); rcu_read_unlock(); } EXPORT_SYMBOL(netpoll_rx_enable); static void refill_skbs(void) { struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&skb_pool.lock, flags); while (skb_pool.qlen < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break; __skb_queue_tail(&skb_pool, skb); } spin_unlock_irqrestore(&skb_pool.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) { atomic_inc(&skb->users); 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 count = 0; struct sk_buff *skb; zap_completion_queue(); refill_skbs(); repeat: skb = alloc_skb(len, GFP_ATOMIC); if (!skb) skb = skb_dequeue(&skb_pool); if (!skb) { if (++count < 10) { netpoll_poll_dev(np->dev); goto repeat; } return NULL; } atomic_set(&skb->users, 1); skb_reserve(skb, reserve); return skb; } static int netpoll_owner_active(struct net_device *dev) { struct napi_struct *napi; list_for_each_entry(napi, &dev->napi_list, dev_list) { if (napi->poll_owner == smp_processor_id()) return 1; } return 0; } /* call with IRQ disabled */ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, struct net_device *dev) { int status = NETDEV_TX_BUSY; unsigned long tries; const struct net_device_ops *ops = dev->netdev_ops; /* It is up to the caller to keep npinfo alive. */ struct netpoll_info *npinfo; WARN_ON_ONCE(!irqs_disabled()); npinfo = rcu_dereference_bh(np->dev->npinfo); if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { __kfree_skb(skb); return; } /* don't get messages out of order, and no recursion */ if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { struct netdev_queue *txq; txq = netdev_pick_tx(dev, skb); /* try until next clock tick */ for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) { if (__netif_tx_trylock(txq)) { if (!netif_xmit_stopped(txq)) { if (vlan_tx_tag_present(skb) && !vlan_hw_offload_capable(netif_skb_features(skb), skb->vlan_proto)) { skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); if (unlikely(!skb)) break; skb->vlan_tci = 0; } status = ops->ndo_start_xmit(skb, dev); if (status == NETDEV_TX_OK) txq_trans_update(txq); } __netif_tx_unlock(txq); if (status == NETDEV_TX_OK) break; } /* tickle device maybe there is some cleanup */ netpoll_poll_dev(np->dev); udelay(USEC_PER_POLL); } WARN_ONCE(!irqs_disabled(), "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", dev->name, ops->ndo_start_xmit); } if (status != NETDEV_TX_OK) { skb_queue_tail(&npinfo->txq, skb); schedule_delayed_work(&npinfo->tx_work,0); } } EXPORT_SYMBOL(netpoll_send_skb_on_dev); void netpoll_send_udp(struct netpoll *np, const char *msg, int len) { int total_len, ip_len, udp_len; struct sk_buff *skb; struct udphdr *udph; struct iphdr *iph; struct ethhdr *eth; static atomic_t ip_ident; struct ipv6hdr *ip6h; udp_len = len + sizeof(*udph); if (np->ipv6) ip_len = udp_len + sizeof(*ip6h); else ip_len = udp_len + sizeof(*iph); total_len = ip_len + LL_RESERVED_SPACE(np->dev); skb = find_skb(np, total_len + np->dev->needed_tailroom, total_len - len); if (!skb) return; skb_copy_to_linear_data(skb, msg, len); skb_put(skb, len); skb_push(skb, sizeof(*udph)); skb_reset_transport_header(skb); udph = udp_hdr(skb); udph->source = htons(np->local_port); udph->dest = htons(np->remote_port); udph->len = htons(udp_len); if (np->ipv6) { udph->check = 0; udph->check = csum_ipv6_magic(&np->local_ip.in6, &np->remote_ip.in6, udp_len, IPPROTO_UDP, csum_partial(udph, udp_len, 0)); if (udph->check == 0) udph->check = CSUM_MANGLED_0; skb_push(skb, sizeof(*ip6h)); skb_reset_network_header(skb); ip6h = ipv6_hdr(skb); /* ip6h->version = 6; ip6h->priority = 0; */ put_unaligned(0x60, (unsigned char *)ip6h); ip6h->flow_lbl[0] = 0; ip6h->flow_lbl[1] = 0; ip6h->flow_lbl[2] = 0; ip6h->payload_len = htons(sizeof(struct udphdr) + len); ip6h->nexthdr = IPPROTO_UDP; ip6h->hop_limit = 32; ip6h->saddr = np->local_ip.in6; ip6h->daddr = np->remote_ip.in6; eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); skb_reset_mac_header(skb); skb->protocol = eth->h_proto = htons(ETH_P_IPV6); } else { udph->check = 0; udph->check = csum_tcpudp_magic(np->local_ip.ip, np->remote_ip.ip, udp_len, IPPROTO_UDP, csum_partial(udph, udp_len, 0)); if (udph->check == 0) udph->check = CSUM_MANGLED_0; skb_push(skb, sizeof(*iph)); skb_reset_network_header(skb); iph = ip_hdr(skb); /* 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 = htons(atomic_inc_return(&ip_ident)); iph->frag_off = 0; iph->ttl = 64; iph->protocol = IPPROTO_UDP; iph->check = 0; put_unaligned(np->local_ip.ip, &(iph->saddr)); put_unaligned(np->remote_ip.ip, &(iph->daddr)); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); skb_reset_mac_header(skb); skb->protocol = eth->h_proto = htons(ETH_P_IP); } memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); skb->dev = np->dev; netpoll_send_skb(np, skb); } EXPORT_SYMBOL(netpoll_send_udp); static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo) { int size, type = ARPOP_REPLY; __be32 sip, tip; unsigned char *sha; struct sk_buff *send_skb; struct netpoll *np, *tmp; unsigned long flags; int hlen, tlen; int hits = 0, proto; if (list_empty(&npinfo->rx_np)) return; /* Before checking the packet, we do some early inspection whether this is interesting at all */ spin_lock_irqsave(&npinfo->rx_lock, flags); list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { if (np->dev == skb->dev) hits++; } spin_unlock_irqrestore(&npinfo->rx_lock, flags); /* No netpoll struct is using this dev */ if (!hits) return; proto = ntohs(eth_hdr(skb)->h_proto); if (proto == ETH_P_IP) { struct arphdr *arp; unsigned char *arp_ptr; /* No arp on this interface */ if (skb->dev->flags & IFF_NOARP) return; if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) return; skb_reset_network_header(skb); skb_reset_transport_header(skb); arp = arp_hdr(skb); 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); /* save the location of the src hw addr */ sha = arp_ptr; arp_ptr += skb->dev->addr_len; memcpy(&sip, arp_ptr, 4); arp_ptr += 4; /* If we actually cared about dst hw addr, it would get copied here */ arp_ptr += skb->dev->addr_len; memcpy(&tip, arp_ptr, 4); /* Should we ignore arp? */ if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) return; size = arp_hdr_len(skb->dev); spin_lock_irqsave(&npinfo->rx_lock, flags); list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { if (tip != np->local_ip.ip) continue; hlen = LL_RESERVED_SPACE(np->dev); tlen = np->dev->needed_tailroom; send_skb = find_skb(np, size + hlen + tlen, hlen); if (!send_skb) continue; skb_reset_network_header(send_skb); 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 (dev_hard_header(send_skb, skb->dev, ETH_P_ARP, sha, np->dev->dev_addr, send_skb->len) < 0) { kfree_skb(send_skb); continue; } /* * 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, sha, np->dev->addr_len); arp_ptr += np->dev->addr_len; memcpy(arp_ptr, &sip, 4); netpoll_send_skb(np, send_skb); /* If there are several rx_hooks for the same address, we're fine by sending a single reply */ break; } spin_unlock_irqrestore(&npinfo->rx_lock, flags); } else if( proto == ETH_P_IPV6) { #if IS_ENABLED(CONFIG_IPV6) struct nd_msg *msg; u8 *lladdr = NULL; struct ipv6hdr *hdr; struct icmp6hdr *icmp6h; const struct in6_addr *saddr; const struct in6_addr *daddr; struct inet6_dev *in6_dev = NULL; struct in6_addr *target; in6_dev = in6_dev_get(skb->dev); if (!in6_dev || !in6_dev->cnf.accept_ra) return; if (!pskb_may_pull(skb, skb->len)) return; msg = (struct nd_msg *)skb_transport_header(skb); __skb_push(skb, skb->data - skb_transport_header(skb)); if (ipv6_hdr(skb)->hop_limit != 255) return; if (msg->icmph.icmp6_code != 0) return; if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) return; saddr = &ipv6_hdr(skb)->saddr; daddr = &ipv6_hdr(skb)->daddr; size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); spin_lock_irqsave(&npinfo->rx_lock, flags); list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { if (!ipv6_addr_equal(daddr, &np->local_ip.in6)) continue; hlen = LL_RESERVED_SPACE(np->dev); tlen = np->dev->needed_tailroom; send_skb = find_skb(np, size + hlen + tlen, hlen); if (!send_skb) continue; send_skb->protocol = htons(ETH_P_IPV6); send_skb->dev = skb->dev; skb_reset_network_header(send_skb); skb_put(send_skb, sizeof(struct ipv6hdr)); hdr = ipv6_hdr(send_skb); *(__be32*)hdr = htonl(0x60000000); hdr->payload_len = htons(size); hdr->nexthdr = IPPROTO_ICMPV6; hdr->hop_limit = 255; hdr->saddr = *saddr; hdr->daddr = *daddr; send_skb->transport_header = send_skb->tail; skb_put(send_skb, size); icmp6h = (struct icmp6hdr *)skb_transport_header(skb); icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; icmp6h->icmp6_router = 0; icmp6h->icmp6_solicited = 1; target = (struct in6_addr *)(skb_transport_header(send_skb) + sizeof(struct icmp6hdr)); *target = msg->target; icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size, IPPROTO_ICMPV6, csum_partial(icmp6h, size, 0)); if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6, lladdr, np->dev->dev_addr, send_skb->len) < 0) { kfree_skb(send_skb); continue; } netpoll_send_skb(np, send_skb); /* If there are several rx_hooks for the same address, we're fine by sending a single reply */ break; } spin_unlock_irqrestore(&npinfo->rx_lock, flags); #endif } } static bool pkt_is_ns(struct sk_buff *skb) { struct nd_msg *msg; struct ipv6hdr *hdr; if (skb->protocol != htons(ETH_P_ARP)) return false; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg))) return false; msg = (struct nd_msg *)skb_transport_header(skb); __skb_push(skb, skb->data - skb_transport_header(skb)); hdr = ipv6_hdr(skb); if (hdr->nexthdr != IPPROTO_ICMPV6) return false; if (hdr->hop_limit != 255) return false; if (msg->icmph.icmp6_code != 0) return false; if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) return false; return true; } int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) { int proto, len, ulen; int hits = 0; const struct iphdr *iph; struct udphdr *uh; struct netpoll *np, *tmp; if (list_empty(&npinfo->rx_np)) goto out; if (skb->dev->type != ARPHRD_ETHER) goto out; /* check if netpoll clients need ARP */ if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) { skb_queue_tail(&npinfo->neigh_tx, skb); return 1; } else if (pkt_is_ns(skb) && atomic_read(&trapped)) { skb_queue_tail(&npinfo->neigh_tx, skb); return 1; } if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { skb = vlan_untag(skb); if (unlikely(!skb)) goto out; } proto = ntohs(eth_hdr(skb)->h_proto); if (proto != ETH_P_IP && proto != ETH_P_IPV6) goto out; if (skb->pkt_type == PACKET_OTHERHOST) goto out; if (skb_shared(skb)) goto out; if (proto == ETH_P_IP) { if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; iph = (struct iphdr *)skb->data; if (iph->ihl < 5 || iph->version != 4) goto out; if (!pskb_may_pull(skb, iph->ihl*4)) goto out; iph = (struct iphdr *)skb->data; 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; /* * Our transport medium may have padded the buffer out. * Now We trim to the true length of the frame. */ if (pskb_trim_rcsum(skb, len)) goto out; iph = (struct iphdr *)skb->data; 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; list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { if (np->local_ip.ip && np->local_ip.ip != iph->daddr) continue; if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr) continue; if (np->local_port && np->local_port != ntohs(uh->dest)) continue; np->rx_hook(np, ntohs(uh->source), (char *)(uh+1), ulen - sizeof(struct udphdr)); hits++; } } else { #if IS_ENABLED(CONFIG_IPV6) const struct ipv6hdr *ip6h; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto out; ip6h = (struct ipv6hdr *)skb->data; if (ip6h->version != 6) goto out; len = ntohs(ip6h->payload_len); if (!len) goto out; if (len + sizeof(struct ipv6hdr) > skb->len) goto out; if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr))) goto out; ip6h = ipv6_hdr(skb); if (!pskb_may_pull(skb, sizeof(struct udphdr))) goto out; uh = udp_hdr(skb); ulen = ntohs(uh->len); if (ulen != skb->len) goto out; if (udp6_csum_init(skb, uh, IPPROTO_UDP)) goto out; list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr)) continue; if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr)) continue; if (np->local_port && np->local_port != ntohs(uh->dest)) continue; np->rx_hook(np, ntohs(uh->source), (char *)(uh+1), ulen - sizeof(struct udphdr)); hits++; } #endif } if (!hits) goto out; kfree_skb(skb); return 1; out: if (atomic_read(&trapped)) { kfree_skb(skb); return 1; } return 0; } void netpoll_print_options(struct netpoll *np) { np_info(np, "local port %d\n", np->local_port); if (np->ipv6) np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); else np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); np_info(np, "interface '%s'\n", np->dev_name); np_info(np, "remote port %d\n", np->remote_port); if (np->ipv6) np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); else np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); np_info(np, "remote ethernet address %pM\n", np->remote_mac); } EXPORT_SYMBOL(netpoll_print_options); static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) { const char *end; if (!strchr(str, ':') && in4_pton(str, -1, (void *)addr, -1, &end) > 0) { if (!*end) return 0; } if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { #if IS_ENABLED(CONFIG_IPV6) if (!*end) return 1; #else return -1; #endif } return -1; } int netpoll_parse_options(struct netpoll *np, char *opt) { char *cur=opt, *delim; int ipv6; if (*cur != '@') { if ((delim = strchr(cur, '@')) == NULL) goto parse_failed; *delim = 0; if (kstrtou16(cur, 10, &np->local_port)) goto parse_failed; cur = delim; } cur++; if (*cur != '/') { if ((delim = strchr(cur, '/')) == NULL) goto parse_failed; *delim = 0; ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); if (ipv6 < 0) goto parse_failed; else np->ipv6 = (bool)ipv6; cur = delim; } cur++; if (*cur != ',') { /* parse out dev name */ if ((delim = strchr(cur, ',')) == NULL) goto parse_failed; *delim = 0; strlcpy(np->dev_name, cur, sizeof(np->dev_name)); cur = delim; } cur++; if (*cur != '@') { /* dst port */ if ((delim = strchr(cur, '@')) == NULL) goto parse_failed; *delim = 0; if (*cur == ' ' || *cur == '\t') np_info(np, "warning: whitespace is not allowed\n"); if (kstrtou16(cur, 10, &np->remote_port)) goto parse_failed; cur = delim; } cur++; /* dst ip */ if ((delim = strchr(cur, '/')) == NULL) goto parse_failed; *delim = 0; ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); if (ipv6 < 0) goto parse_failed; else if (np->ipv6 != (bool)ipv6) goto parse_failed; else np->ipv6 = (bool)ipv6; cur = delim + 1; if (*cur != 0) { /* MAC address */ if (!mac_pton(cur, np->remote_mac)) goto parse_failed; } netpoll_print_options(np); return 0; parse_failed: np_info(np, "couldn't parse config at '%s'!\n", cur); return -1; } EXPORT_SYMBOL(netpoll_parse_options); int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) { struct netpoll_info *npinfo; const struct net_device_ops *ops; unsigned long flags; int err; np->dev = ndev; strlcpy(np->dev_name, ndev->name, IFNAMSIZ); INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || !ndev->netdev_ops->ndo_poll_controller) { np_err(np, "%s doesn't support polling, aborting\n", np->dev_name); err = -ENOTSUPP; goto out; } if (!ndev->npinfo) { npinfo = kmalloc(sizeof(*npinfo), gfp); if (!npinfo) { err = -ENOMEM; goto out; } npinfo->rx_flags = 0; INIT_LIST_HEAD(&npinfo->rx_np); spin_lock_init(&npinfo->rx_lock); sema_init(&npinfo->dev_lock, 1); skb_queue_head_init(&npinfo->neigh_tx); skb_queue_head_init(&npinfo->txq); INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); atomic_set(&npinfo->refcnt, 1); ops = np->dev->netdev_ops; if (ops->ndo_netpoll_setup) { err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); if (err) goto free_npinfo; } } else { npinfo = rtnl_dereference(ndev->npinfo); atomic_inc(&npinfo->refcnt); } npinfo->netpoll = np; if (np->rx_hook) { spin_lock_irqsave(&npinfo->rx_lock, flags); npinfo->rx_flags |= NETPOLL_RX_ENABLED; list_add_tail(&np->rx, &npinfo->rx_np); spin_unlock_irqrestore(&npinfo->rx_lock, flags); } /* last thing to do is link it to the net device structure */ rcu_assign_pointer(ndev->npinfo, npinfo); return 0; free_npinfo: kfree(npinfo); out: return err; } EXPORT_SYMBOL_GPL(__netpoll_setup); int netpoll_setup(struct netpoll *np) { struct net_device *ndev = NULL; struct in_device *in_dev; int err; rtnl_lock(); if (np->dev_name) { struct net *net = current->nsproxy->net_ns; ndev = __dev_get_by_name(net, np->dev_name); } if (!ndev) { np_err(np, "%s doesn't exist, aborting\n", np->dev_name); err = -ENODEV; goto unlock; } dev_hold(ndev); if (netdev_master_upper_dev_get(ndev)) { np_err(np, "%s is a slave device, aborting\n", np->dev_name); err = -EBUSY; goto put; } if (!netif_running(ndev)) { unsigned long atmost, atleast; np_info(np, "device %s not up yet, forcing it\n", np->dev_name); err = dev_open(ndev); if (err) { np_err(np, "failed to open %s\n", ndev->name); goto put; } rtnl_unlock(); atleast = jiffies + HZ/10; atmost = jiffies + carrier_timeout * HZ; while (!netif_carrier_ok(ndev)) { if (time_after(jiffies, atmost)) { np_notice(np, "timeout waiting for carrier\n"); break; } msleep(1); } /* If carrier appears to come up instantly, we don't * trust it and pause so that we don't pump all our * queued console messages into the bitbucket. */ if (time_before(jiffies, atleast)) { np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); msleep(4000); } rtnl_lock(); } if (!np->local_ip.ip) { if (!np->ipv6) { in_dev = __in_dev_get_rtnl(ndev); if (!in_dev || !in_dev->ifa_list) { np_err(np, "no IP address for %s, aborting\n", np->dev_name); err = -EDESTADDRREQ; goto put; } np->local_ip.ip = in_dev->ifa_list->ifa_local; np_info(np, "local IP %pI4\n", &np->local_ip.ip); } else { #if IS_ENABLED(CONFIG_IPV6) struct inet6_dev *idev; err = -EDESTADDRREQ; idev = __in6_dev_get(ndev); if (idev) { struct inet6_ifaddr *ifp; read_lock_bh(&idev->lock); list_for_each_entry(ifp, &idev->addr_list, if_list) { if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) continue; np->local_ip.in6 = ifp->addr; err = 0; break; } read_unlock_bh(&idev->lock); } if (err) { np_err(np, "no IPv6 address for %s, aborting\n", np->dev_name); goto put; } else np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); #else np_err(np, "IPv6 is not supported %s, aborting\n", np->dev_name); err = -EINVAL; goto put; #endif } } /* fill up the skb queue */ refill_skbs(); err = __netpoll_setup(np, ndev, GFP_KERNEL); if (err) goto put; rtnl_unlock(); return 0; put: dev_put(ndev); unlock: rtnl_unlock(); return err; } EXPORT_SYMBOL(netpoll_setup); static int __init netpoll_init(void) { skb_queue_head_init(&skb_pool); return 0; } core_initcall(netpoll_init); static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) { struct netpoll_info *npinfo = container_of(rcu_head, struct netpoll_info, rcu); skb_queue_purge(&npinfo->neigh_tx); skb_queue_purge(&npinfo->txq); /* we can't call cancel_delayed_work_sync here, as we are in softirq */ cancel_delayed_work(&npinfo->tx_work); /* clean after last, unfinished work */ __skb_queue_purge(&npinfo->txq); /* now cancel it again */ cancel_delayed_work(&npinfo->tx_work); kfree(npinfo); } void __netpoll_cleanup(struct netpoll *np) { struct netpoll_info *npinfo; unsigned long flags; /* rtnl_dereference would be preferable here but * rcu_cleanup_netpoll path can put us in here safely without * holding the rtnl, so plain rcu_dereference it is */ npinfo = rtnl_dereference(np->dev->npinfo); if (!npinfo) return; if (!list_empty(&npinfo->rx_np)) { spin_lock_irqsave(&npinfo->rx_lock, flags); list_del(&np->rx); if (list_empty(&npinfo->rx_np)) npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; spin_unlock_irqrestore(&npinfo->rx_lock, flags); } synchronize_srcu(&netpoll_srcu); if (atomic_dec_and_test(&npinfo->refcnt)) { const struct net_device_ops *ops; ops = np->dev->netdev_ops; if (ops->ndo_netpoll_cleanup) ops->ndo_netpoll_cleanup(np->dev); rcu_assign_pointer(np->dev->npinfo, NULL); call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); } } EXPORT_SYMBOL_GPL(__netpoll_cleanup); static void netpoll_async_cleanup(struct work_struct *work) { struct netpoll *np = container_of(work, struct netpoll, cleanup_work); rtnl_lock(); __netpoll_cleanup(np); rtnl_unlock(); kfree(np); } void __netpoll_free_async(struct netpoll *np) { schedule_work(&np->cleanup_work); } EXPORT_SYMBOL_GPL(__netpoll_free_async); void netpoll_cleanup(struct netpoll *np) { if (!np->dev) return; rtnl_lock(); __netpoll_cleanup(np); rtnl_unlock(); dev_put(np->dev); np->dev = NULL; } EXPORT_SYMBOL(netpoll_cleanup); int netpoll_trap(void) { return atomic_read(&trapped); } EXPORT_SYMBOL(netpoll_trap); void netpoll_set_trap(int trap) { if (trap) atomic_inc(&trapped); else atomic_dec(&trapped); } EXPORT_SYMBOL(netpoll_set_trap);