diff options
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 183 |
1 files changed, 86 insertions, 97 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index bba150fdd265..f6787c55f6ab 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -21,7 +21,7 @@ * Alan Cox : Added BSD route gw semantics * Alan Cox : Super /proc >4K * Alan Cox : MTU in route table - * Alan Cox : MSS actually. Also added the window + * Alan Cox : MSS actually. Also added the window * clamper. * Sam Lantinga : Fixed route matching in rt_del() * Alan Cox : Routing cache support. @@ -41,7 +41,7 @@ * Olaf Erb : irtt wasn't being copied right. * Bjorn Ekwall : Kerneld route support. * Alan Cox : Multicast fixed (I hope) - * Pavel Krauz : Limited broadcast fixed + * Pavel Krauz : Limited broadcast fixed * Mike McLagan : Routing by source * Alexey Kuznetsov : End of old history. Split to fib.c and * route.c and rewritten from scratch. @@ -54,8 +54,8 @@ * Robert Olsson : Added rt_cache statistics * Arnaldo C. Melo : Convert proc stuff to seq_file * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. - * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect - * Ilia Sotnikov : Removed TOS from hash calculations + * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect + * Ilia Sotnikov : Removed TOS from hash calculations */ #define pr_fmt(fmt) "IPv4: " fmt @@ -66,6 +66,7 @@ #include <linux/types.h> #include <linux/kernel.h> #include <linux/mm.h> +#include <linux/memblock.h> #include <linux/string.h> #include <linux/socket.h> #include <linux/sockios.h> @@ -234,19 +235,6 @@ static const struct seq_operations rt_cache_seq_ops = { .show = rt_cache_seq_show, }; -static int rt_cache_seq_open(struct inode *inode, struct file *file) -{ - return seq_open(file, &rt_cache_seq_ops); -} - -static const struct proc_ops rt_cache_proc_ops = { - .proc_open = rt_cache_seq_open, - .proc_read = seq_read, - .proc_lseek = seq_lseek, - .proc_release = seq_release, -}; - - static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) { int cpu; @@ -324,19 +312,6 @@ static const struct seq_operations rt_cpu_seq_ops = { .show = rt_cpu_seq_show, }; - -static int rt_cpu_seq_open(struct inode *inode, struct file *file) -{ - return seq_open(file, &rt_cpu_seq_ops); -} - -static const struct proc_ops rt_cpu_proc_ops = { - .proc_open = rt_cpu_seq_open, - .proc_read = seq_read, - .proc_lseek = seq_lseek, - .proc_release = seq_release, -}; - #ifdef CONFIG_IP_ROUTE_CLASSID static int rt_acct_proc_show(struct seq_file *m, void *v) { @@ -367,13 +342,13 @@ static int __net_init ip_rt_do_proc_init(struct net *net) { struct proc_dir_entry *pde; - pde = proc_create("rt_cache", 0444, net->proc_net, - &rt_cache_proc_ops); + pde = proc_create_seq("rt_cache", 0444, net->proc_net, + &rt_cache_seq_ops); if (!pde) goto err1; - pde = proc_create("rt_cache", 0444, - net->proc_net_stat, &rt_cpu_proc_ops); + pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, + &rt_cpu_seq_ops); if (!pde) goto err2; @@ -478,8 +453,10 @@ static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); } -#define IP_IDENTS_SZ 2048u - +/* Hash tables of size 2048..262144 depending on RAM size. + * Each bucket uses 8 bytes. + */ +static u32 ip_idents_mask __read_mostly; static atomic_t *ip_idents __read_mostly; static u32 *ip_tstamps __read_mostly; @@ -489,12 +466,16 @@ static u32 *ip_tstamps __read_mostly; */ u32 ip_idents_reserve(u32 hash, int segs) { - u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; - atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; - u32 old = READ_ONCE(*p_tstamp); - u32 now = (u32)jiffies; + u32 bucket, old, now = (u32)jiffies; + atomic_t *p_id; + u32 *p_tstamp; u32 delta = 0; + bucket = hash & ip_idents_mask; + p_tstamp = ip_tstamps + bucket; + p_id = ip_idents + bucket; + old = READ_ONCE(*p_tstamp); + if (old != now && cmpxchg(p_tstamp, old, now) == old) delta = prandom_u32_max(now - old); @@ -722,6 +703,7 @@ static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, for_each_possible_cpu(i) { struct rtable __rcu **prt; + prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); rt = rcu_dereference(*prt); if (rt) @@ -1258,12 +1240,12 @@ static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) } /* - We do not cache source address of outgoing interface, - because it is used only by IP RR, TS and SRR options, - so that it out of fast path. - - BTW remember: "addr" is allowed to be not aligned - in IP options! + * We do not cache source address of outgoing interface, + * because it is used only by IP RR, TS and SRR options, + * so that it out of fast path. + * + * BTW remember: "addr" is allowed to be not aligned + * in IP options! */ void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) @@ -2108,7 +2090,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, goto out; /* Check for the most weird martians, which can be not detected - by fib_lookup. + * by fib_lookup. */ tun_info = skb_tunnel_info(skb); @@ -2246,7 +2228,7 @@ local_input: if (res->type == RTN_UNREACHABLE) { rth->dst.input= ip_error; rth->dst.error= -err; - rth->rt_flags &= ~RTCF_LOCAL; + rth->rt_flags &= ~RTCF_LOCAL; } if (do_cache) { @@ -2317,15 +2299,15 @@ int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, u8 tos, struct net_device *dev, struct fib_result *res) { /* Multicast recognition logic is moved from route cache to here. - The problem was that too many Ethernet cards have broken/missing - hardware multicast filters :-( As result the host on multicasting - network acquires a lot of useless route cache entries, sort of - SDR messages from all the world. Now we try to get rid of them. - Really, provided software IP multicast filter is organized - reasonably (at least, hashed), it does not result in a slowdown - comparing with route cache reject entries. - Note, that multicast routers are not affected, because - route cache entry is created eventually. + * The problem was that too many Ethernet cards have broken/missing + * hardware multicast filters :-( As result the host on multicasting + * network acquires a lot of useless route cache entries, sort of + * SDR messages from all the world. Now we try to get rid of them. + * Really, provided software IP multicast filter is organized + * reasonably (at least, hashed), it does not result in a slowdown + * comparing with route cache reject entries. + * Note, that multicast routers are not affected, because + * route cache entry is created eventually. */ if (ipv4_is_multicast(daddr)) { struct in_device *in_dev = __in_dev_get_rcu(dev); @@ -2537,11 +2519,11 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, rth = ERR_PTR(-ENETUNREACH); /* I removed check for oif == dev_out->oif here. - It was wrong for two reasons: - 1. ip_dev_find(net, saddr) can return wrong iface, if saddr - is assigned to multiple interfaces. - 2. Moreover, we are allowed to send packets with saddr - of another iface. --ANK + * It was wrong for two reasons: + * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr + * is assigned to multiple interfaces. + * 2. Moreover, we are allowed to send packets with saddr + * of another iface. --ANK */ if (fl4->flowi4_oif == 0 && @@ -2553,18 +2535,18 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, goto out; /* Special hack: user can direct multicasts - and limited broadcast via necessary interface - without fiddling with IP_MULTICAST_IF or IP_PKTINFO. - This hack is not just for fun, it allows - vic,vat and friends to work. - They bind socket to loopback, set ttl to zero - and expect that it will work. - From the viewpoint of routing cache they are broken, - because we are not allowed to build multicast path - with loopback source addr (look, routing cache - cannot know, that ttl is zero, so that packet - will not leave this host and route is valid). - Luckily, this hack is good workaround. + * and limited broadcast via necessary interface + * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. + * This hack is not just for fun, it allows + * vic,vat and friends to work. + * They bind socket to loopback, set ttl to zero + * and expect that it will work. + * From the viewpoint of routing cache they are broken, + * because we are not allowed to build multicast path + * with loopback source addr (look, routing cache + * cannot know, that ttl is zero, so that packet + * will not leave this host and route is valid). + * Luckily, this hack is good workaround. */ fl4->flowi4_oif = dev_out->ifindex; @@ -2627,21 +2609,21 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, (ipv4_is_multicast(fl4->daddr) || !netif_index_is_l3_master(net, fl4->flowi4_oif))) { /* Apparently, routing tables are wrong. Assume, - that the destination is on link. - - WHY? DW. - Because we are allowed to send to iface - even if it has NO routes and NO assigned - addresses. When oif is specified, routing - tables are looked up with only one purpose: - to catch if destination is gatewayed, rather than - direct. Moreover, if MSG_DONTROUTE is set, - we send packet, ignoring both routing tables - and ifaddr state. --ANK - - - We could make it even if oif is unknown, - likely IPv6, but we do not. + * that the destination is on link. + * + * WHY? DW. + * Because we are allowed to send to iface + * even if it has NO routes and NO assigned + * addresses. When oif is specified, routing + * tables are looked up with only one purpose: + * to catch if destination is gatewayed, rather than + * direct. Moreover, if MSG_DONTROUTE is set, + * we send packet, ignoring both routing tables + * and ifaddr state. --ANK + * + * + * We could make it even if oif is unknown, + * likely IPv6, but we do not. */ if (fl4->saddr == 0) @@ -3553,18 +3535,25 @@ struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; int __init ip_rt_init(void) { + void *idents_hash; int cpu; - ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), - GFP_KERNEL); - if (!ip_idents) - panic("IP: failed to allocate ip_idents\n"); + /* For modern hosts, this will use 2 MB of memory */ + idents_hash = alloc_large_system_hash("IP idents", + sizeof(*ip_idents) + sizeof(*ip_tstamps), + 0, + 16, /* one bucket per 64 KB */ + HASH_ZERO, + NULL, + &ip_idents_mask, + 2048, + 256*1024); + + ip_idents = idents_hash; - prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); + prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); - ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); - if (!ip_tstamps) - panic("IP: failed to allocate ip_tstamps\n"); + ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); for_each_possible_cpu(cpu) { struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); |