/* * ip6_flowlabel.c IPv6 flowlabel manager. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> */ #include <linux/capability.h> #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/net.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/in6.h> #include <linux/route.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/export.h> #include <net/net_namespace.h> #include <net/sock.h> #include <net/ipv6.h> #include <net/ndisc.h> #include <net/protocol.h> #include <net/ip6_route.h> #include <net/addrconf.h> #include <net/rawv6.h> #include <net/icmp.h> #include <net/transp_v6.h> #include <asm/uaccess.h> #define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified in old IPv6 RFC. Well, it was reasonable value. */ #define FL_MAX_LINGER 60 /* Maximal linger timeout */ /* FL hash table */ #define FL_MAX_PER_SOCK 32 #define FL_MAX_SIZE 4096 #define FL_HASH_MASK 255 #define FL_HASH(l) (ntohl(l)&FL_HASH_MASK) static atomic_t fl_size = ATOMIC_INIT(0); static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1]; static void ip6_fl_gc(unsigned long dummy); static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0); /* FL hash table lock: it protects only of GC */ static DEFINE_RWLOCK(ip6_fl_lock); /* Big socket sock */ static DEFINE_RWLOCK(ip6_sk_fl_lock); static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label) { struct ip6_flowlabel *fl; for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) { if (fl->label == label && net_eq(fl->fl_net, net)) return fl; } return NULL; } static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label) { struct ip6_flowlabel *fl; read_lock_bh(&ip6_fl_lock); fl = __fl_lookup(net, label); if (fl) atomic_inc(&fl->users); read_unlock_bh(&ip6_fl_lock); return fl; } static void fl_free(struct ip6_flowlabel *fl) { if (fl) { release_net(fl->fl_net); kfree(fl->opt); } kfree(fl); } static void fl_release(struct ip6_flowlabel *fl) { write_lock_bh(&ip6_fl_lock); fl->lastuse = jiffies; if (atomic_dec_and_test(&fl->users)) { unsigned long ttd = fl->lastuse + fl->linger; if (time_after(ttd, fl->expires)) fl->expires = ttd; ttd = fl->expires; if (fl->opt && fl->share == IPV6_FL_S_EXCL) { struct ipv6_txoptions *opt = fl->opt; fl->opt = NULL; kfree(opt); } if (!timer_pending(&ip6_fl_gc_timer) || time_after(ip6_fl_gc_timer.expires, ttd)) mod_timer(&ip6_fl_gc_timer, ttd); } write_unlock_bh(&ip6_fl_lock); } static void ip6_fl_gc(unsigned long dummy) { int i; unsigned long now = jiffies; unsigned long sched = 0; write_lock(&ip6_fl_lock); for (i=0; i<=FL_HASH_MASK; i++) { struct ip6_flowlabel *fl, **flp; flp = &fl_ht[i]; while ((fl=*flp) != NULL) { if (atomic_read(&fl->users) == 0) { unsigned long ttd = fl->lastuse + fl->linger; if (time_after(ttd, fl->expires)) fl->expires = ttd; ttd = fl->expires; if (time_after_eq(now, ttd)) { *flp = fl->next; fl_free(fl); atomic_dec(&fl_size); continue; } if (!sched || time_before(ttd, sched)) sched = ttd; } flp = &fl->next; } } if (!sched && atomic_read(&fl_size)) sched = now + FL_MAX_LINGER; if (sched) { mod_timer(&ip6_fl_gc_timer, sched); } write_unlock(&ip6_fl_lock); } static void __net_exit ip6_fl_purge(struct net *net) { int i; write_lock(&ip6_fl_lock); for (i = 0; i <= FL_HASH_MASK; i++) { struct ip6_flowlabel *fl, **flp; flp = &fl_ht[i]; while ((fl = *flp) != NULL) { if (net_eq(fl->fl_net, net) && atomic_read(&fl->users) == 0) { *flp = fl->next; fl_free(fl); atomic_dec(&fl_size); continue; } flp = &fl->next; } } write_unlock(&ip6_fl_lock); } static struct ip6_flowlabel *fl_intern(struct net *net, struct ip6_flowlabel *fl, __be32 label) { struct ip6_flowlabel *lfl; fl->label = label & IPV6_FLOWLABEL_MASK; write_lock_bh(&ip6_fl_lock); if (label == 0) { for (;;) { fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK; if (fl->label) { lfl = __fl_lookup(net, fl->label); if (lfl == NULL) break; } } } else { /* * we dropper the ip6_fl_lock, so this entry could reappear * and we need to recheck with it. * * OTOH no need to search the active socket first, like it is * done in ipv6_flowlabel_opt - sock is locked, so new entry * with the same label can only appear on another sock */ lfl = __fl_lookup(net, fl->label); if (lfl != NULL) { atomic_inc(&lfl->users); write_unlock_bh(&ip6_fl_lock); return lfl; } } fl->lastuse = jiffies; fl->next = fl_ht[FL_HASH(fl->label)]; fl_ht[FL_HASH(fl->label)] = fl; atomic_inc(&fl_size); write_unlock_bh(&ip6_fl_lock); return NULL; } /* Socket flowlabel lists */ struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label) { struct ipv6_fl_socklist *sfl; struct ipv6_pinfo *np = inet6_sk(sk); label &= IPV6_FLOWLABEL_MASK; read_lock_bh(&ip6_sk_fl_lock); for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) { struct ip6_flowlabel *fl = sfl->fl; if (fl->label == label) { fl->lastuse = jiffies; atomic_inc(&fl->users); read_unlock_bh(&ip6_sk_fl_lock); return fl; } } read_unlock_bh(&ip6_sk_fl_lock); return NULL; } EXPORT_SYMBOL_GPL(fl6_sock_lookup); void fl6_free_socklist(struct sock *sk) { struct ipv6_pinfo *np = inet6_sk(sk); struct ipv6_fl_socklist *sfl; while ((sfl = np->ipv6_fl_list) != NULL) { np->ipv6_fl_list = sfl->next; fl_release(sfl->fl); kfree(sfl); } } /* Service routines */ /* It is the only difficult place. flowlabel enforces equal headers before and including routing header, however user may supply options following rthdr. */ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space, struct ip6_flowlabel * fl, struct ipv6_txoptions * fopt) { struct ipv6_txoptions * fl_opt = fl->opt; if (fopt == NULL || fopt->opt_flen == 0) return fl_opt; if (fl_opt != NULL) { opt_space->hopopt = fl_opt->hopopt; opt_space->dst0opt = fl_opt->dst0opt; opt_space->srcrt = fl_opt->srcrt; opt_space->opt_nflen = fl_opt->opt_nflen; } else { if (fopt->opt_nflen == 0) return fopt; opt_space->hopopt = NULL; opt_space->dst0opt = NULL; opt_space->srcrt = NULL; opt_space->opt_nflen = 0; } opt_space->dst1opt = fopt->dst1opt; opt_space->opt_flen = fopt->opt_flen; return opt_space; } static unsigned long check_linger(unsigned long ttl) { if (ttl < FL_MIN_LINGER) return FL_MIN_LINGER*HZ; if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN)) return 0; return ttl*HZ; } static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires) { linger = check_linger(linger); if (!linger) return -EPERM; expires = check_linger(expires); if (!expires) return -EPERM; fl->lastuse = jiffies; if (time_before(fl->linger, linger)) fl->linger = linger; if (time_before(expires, fl->linger)) expires = fl->linger; if (time_before(fl->expires, fl->lastuse + expires)) fl->expires = fl->lastuse + expires; return 0; } static struct ip6_flowlabel * fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p) { struct ip6_flowlabel *fl = NULL; int olen; int addr_type; int err; olen = optlen - CMSG_ALIGN(sizeof(*freq)); err = -EINVAL; if (olen > 64 * 1024) goto done; err = -ENOMEM; fl = kzalloc(sizeof(*fl), GFP_KERNEL); if (fl == NULL) goto done; if (olen > 0) { struct msghdr msg; struct flowi6 flowi6; int junk; err = -ENOMEM; fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL); if (fl->opt == NULL) goto done; memset(fl->opt, 0, sizeof(*fl->opt)); fl->opt->tot_len = sizeof(*fl->opt) + olen; err = -EFAULT; if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen)) goto done; msg.msg_controllen = olen; msg.msg_control = (void*)(fl->opt+1); memset(&flowi6, 0, sizeof(flowi6)); err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk, &junk, &junk); if (err) goto done; err = -EINVAL; if (fl->opt->opt_flen) goto done; if (fl->opt->opt_nflen == 0) { kfree(fl->opt); fl->opt = NULL; } } fl->fl_net = hold_net(net); fl->expires = jiffies; err = fl6_renew(fl, freq->flr_linger, freq->flr_expires); if (err) goto done; fl->share = freq->flr_share; addr_type = ipv6_addr_type(&freq->flr_dst); if ((addr_type & IPV6_ADDR_MAPPED) || addr_type == IPV6_ADDR_ANY) { err = -EINVAL; goto done; } fl->dst = freq->flr_dst; atomic_set(&fl->users, 1); switch (fl->share) { case IPV6_FL_S_EXCL: case IPV6_FL_S_ANY: break; case IPV6_FL_S_PROCESS: fl->owner = current->pid; break; case IPV6_FL_S_USER: fl->owner = current_euid(); break; default: err = -EINVAL; goto done; } return fl; done: fl_free(fl); *err_p = err; return NULL; } static int mem_check(struct sock *sk) { struct ipv6_pinfo *np = inet6_sk(sk); struct ipv6_fl_socklist *sfl; int room = FL_MAX_SIZE - atomic_read(&fl_size); int count = 0; if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK) return 0; for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) count++; if (room <= 0 || ((count >= FL_MAX_PER_SOCK || (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) && !capable(CAP_NET_ADMIN))) return -ENOBUFS; return 0; } static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2) { if (h1 == h2) return 0; if (h1 == NULL || h2 == NULL) return 1; if (h1->hdrlen != h2->hdrlen) return 1; return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1)); } static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2) { if (o1 == o2) return 0; if (o1 == NULL || o2 == NULL) return 1; if (o1->opt_nflen != o2->opt_nflen) return 1; if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt)) return 1; if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt)) return 1; if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt)) return 1; return 0; } static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl, struct ip6_flowlabel *fl) { write_lock_bh(&ip6_sk_fl_lock); sfl->fl = fl; sfl->next = np->ipv6_fl_list; np->ipv6_fl_list = sfl; write_unlock_bh(&ip6_sk_fl_lock); } int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen) { int uninitialized_var(err); struct net *net = sock_net(sk); struct ipv6_pinfo *np = inet6_sk(sk); struct in6_flowlabel_req freq; struct ipv6_fl_socklist *sfl1=NULL; struct ipv6_fl_socklist *sfl, **sflp; struct ip6_flowlabel *fl, *fl1 = NULL; if (optlen < sizeof(freq)) return -EINVAL; if (copy_from_user(&freq, optval, sizeof(freq))) return -EFAULT; switch (freq.flr_action) { case IPV6_FL_A_PUT: write_lock_bh(&ip6_sk_fl_lock); for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) { if (sfl->fl->label == freq.flr_label) { if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK)) np->flow_label &= ~IPV6_FLOWLABEL_MASK; *sflp = sfl->next; write_unlock_bh(&ip6_sk_fl_lock); fl_release(sfl->fl); kfree(sfl); return 0; } } write_unlock_bh(&ip6_sk_fl_lock); return -ESRCH; case IPV6_FL_A_RENEW: read_lock_bh(&ip6_sk_fl_lock); for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) { if (sfl->fl->label == freq.flr_label) { err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires); read_unlock_bh(&ip6_sk_fl_lock); return err; } } read_unlock_bh(&ip6_sk_fl_lock); if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) { fl = fl_lookup(net, freq.flr_label); if (fl) { err = fl6_renew(fl, freq.flr_linger, freq.flr_expires); fl_release(fl); return err; } } return -ESRCH; case IPV6_FL_A_GET: if (freq.flr_label & ~IPV6_FLOWLABEL_MASK) return -EINVAL; fl = fl_create(net, sk, &freq, optval, optlen, &err); if (fl == NULL) return err; sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL); if (freq.flr_label) { err = -EEXIST; read_lock_bh(&ip6_sk_fl_lock); for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) { if (sfl->fl->label == freq.flr_label) { if (freq.flr_flags&IPV6_FL_F_EXCL) { read_unlock_bh(&ip6_sk_fl_lock); goto done; } fl1 = sfl->fl; atomic_inc(&fl1->users); break; } } read_unlock_bh(&ip6_sk_fl_lock); if (fl1 == NULL) fl1 = fl_lookup(net, freq.flr_label); if (fl1) { recheck: err = -EEXIST; if (freq.flr_flags&IPV6_FL_F_EXCL) goto release; err = -EPERM; if (fl1->share == IPV6_FL_S_EXCL || fl1->share != fl->share || fl1->owner != fl->owner) goto release; err = -EINVAL; if (!ipv6_addr_equal(&fl1->dst, &fl->dst) || ipv6_opt_cmp(fl1->opt, fl->opt)) goto release; err = -ENOMEM; if (sfl1 == NULL) goto release; if (fl->linger > fl1->linger) fl1->linger = fl->linger; if ((long)(fl->expires - fl1->expires) > 0) fl1->expires = fl->expires; fl_link(np, sfl1, fl1); fl_free(fl); return 0; release: fl_release(fl1); goto done; } } err = -ENOENT; if (!(freq.flr_flags&IPV6_FL_F_CREATE)) goto done; err = -ENOMEM; if (sfl1 == NULL || (err = mem_check(sk)) != 0) goto done; fl1 = fl_intern(net, fl, freq.flr_label); if (fl1 != NULL) goto recheck; if (!freq.flr_label) { if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label, &fl->label, sizeof(fl->label))) { /* Intentionally ignore fault. */ } } fl_link(np, sfl1, fl); return 0; default: return -EINVAL; } done: fl_free(fl); kfree(sfl1); return err; } #ifdef CONFIG_PROC_FS struct ip6fl_iter_state { struct seq_net_private p; int bucket; }; #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private) static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq) { struct ip6_flowlabel *fl = NULL; struct ip6fl_iter_state *state = ip6fl_seq_private(seq); struct net *net = seq_file_net(seq); for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) { fl = fl_ht[state->bucket]; while (fl && !net_eq(fl->fl_net, net)) fl = fl->next; if (fl) break; } return fl; } static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl) { struct ip6fl_iter_state *state = ip6fl_seq_private(seq); struct net *net = seq_file_net(seq); fl = fl->next; try_again: while (fl && !net_eq(fl->fl_net, net)) fl = fl->next; while (!fl) { if (++state->bucket <= FL_HASH_MASK) { fl = fl_ht[state->bucket]; goto try_again; } else break; } return fl; } static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos) { struct ip6_flowlabel *fl = ip6fl_get_first(seq); if (fl) while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL) --pos; return pos ? NULL : fl; } static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos) __acquires(ip6_fl_lock) { read_lock_bh(&ip6_fl_lock); return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; } static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct ip6_flowlabel *fl; if (v == SEQ_START_TOKEN) fl = ip6fl_get_first(seq); else fl = ip6fl_get_next(seq, v); ++*pos; return fl; } static void ip6fl_seq_stop(struct seq_file *seq, void *v) __releases(ip6_fl_lock) { read_unlock_bh(&ip6_fl_lock); } static int ip6fl_seq_show(struct seq_file *seq, void *v) { if (v == SEQ_START_TOKEN) seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n", "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt"); else { struct ip6_flowlabel *fl = v; seq_printf(seq, "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n", (unsigned)ntohl(fl->label), fl->share, (unsigned)fl->owner, atomic_read(&fl->users), fl->linger/HZ, (long)(fl->expires - jiffies)/HZ, &fl->dst, fl->opt ? fl->opt->opt_nflen : 0); } return 0; } static const struct seq_operations ip6fl_seq_ops = { .start = ip6fl_seq_start, .next = ip6fl_seq_next, .stop = ip6fl_seq_stop, .show = ip6fl_seq_show, }; static int ip6fl_seq_open(struct inode *inode, struct file *file) { return seq_open_net(inode, file, &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)); } static const struct file_operations ip6fl_seq_fops = { .owner = THIS_MODULE, .open = ip6fl_seq_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_net, }; static int __net_init ip6_flowlabel_proc_init(struct net *net) { if (!proc_net_fops_create(net, "ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops)) return -ENOMEM; return 0; } static void __net_exit ip6_flowlabel_proc_fini(struct net *net) { proc_net_remove(net, "ip6_flowlabel"); } #else static inline int ip6_flowlabel_proc_init(struct net *net) { return 0; } static inline void ip6_flowlabel_proc_fini(struct net *net) { } #endif static void __net_exit ip6_flowlabel_net_exit(struct net *net) { ip6_fl_purge(net); ip6_flowlabel_proc_fini(net); } static struct pernet_operations ip6_flowlabel_net_ops = { .init = ip6_flowlabel_proc_init, .exit = ip6_flowlabel_net_exit, }; int ip6_flowlabel_init(void) { return register_pernet_subsys(&ip6_flowlabel_net_ops); } void ip6_flowlabel_cleanup(void) { del_timer(&ip6_fl_gc_timer); unregister_pernet_subsys(&ip6_flowlabel_net_ops); }