Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Evgeniy Polyakov | 1221 | 57.06% | 1 | 3.57% |
Fernando Fernandez Mancera | 397 | 18.55% | 6 | 21.43% |
Pablo Neira Ayuso | 371 | 17.34% | 7 | 25.00% |
Wander Lairson Costa | 59 | 2.76% | 1 | 3.57% |
Kevin Cernekee | 27 | 1.26% | 1 | 3.57% |
Arnd Bergmann | 19 | 0.89% | 1 | 3.57% |
Florian Westphal | 14 | 0.65% | 2 | 7.14% |
Jan Engelhardt | 9 | 0.42% | 1 | 3.57% |
Patrick McHardy | 9 | 0.42% | 3 | 10.71% |
Joe Perches | 5 | 0.23% | 2 | 7.14% |
Gao Feng | 4 | 0.19% | 1 | 3.57% |
Lai Jiangshan | 4 | 0.19% | 1 | 3.57% |
Thomas Gleixner | 1 | 0.05% | 1 | 3.57% |
Total | 2140 | 28 |
// SPDX-License-Identifier: GPL-2.0-only #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/kernel.h> #include <linux/capability.h> #include <linux/if.h> #include <linux/inetdevice.h> #include <linux/ip.h> #include <linux/list.h> #include <linux/rculist.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/tcp.h> #include <net/ip.h> #include <net/tcp.h> #include <linux/netfilter/nfnetlink.h> #include <linux/netfilter/x_tables.h> #include <net/netfilter/nf_log.h> #include <linux/netfilter/nfnetlink_osf.h> /* * Indexed by dont-fragment bit. * It is the only constant value in the fingerprint. */ struct list_head nf_osf_fingers[2]; EXPORT_SYMBOL_GPL(nf_osf_fingers); static inline int nf_osf_ttl(const struct sk_buff *skb, int ttl_check, unsigned char f_ttl) { struct in_device *in_dev = __in_dev_get_rcu(skb->dev); const struct iphdr *ip = ip_hdr(skb); const struct in_ifaddr *ifa; int ret = 0; if (ttl_check == NF_OSF_TTL_TRUE) return ip->ttl == f_ttl; if (ttl_check == NF_OSF_TTL_NOCHECK) return 1; else if (ip->ttl <= f_ttl) return 1; in_dev_for_each_ifa_rcu(ifa, in_dev) { if (inet_ifa_match(ip->saddr, ifa)) { ret = (ip->ttl == f_ttl); break; } } return ret; } struct nf_osf_hdr_ctx { bool df; u16 window; u16 totlen; const unsigned char *optp; unsigned int optsize; }; static bool nf_osf_match_one(const struct sk_buff *skb, const struct nf_osf_user_finger *f, int ttl_check, struct nf_osf_hdr_ctx *ctx) { const __u8 *optpinit = ctx->optp; unsigned int check_WSS = 0; int fmatch = FMATCH_WRONG; int foptsize, optnum; u16 mss = 0; if (ctx->totlen != f->ss || !nf_osf_ttl(skb, ttl_check, f->ttl)) return false; /* * Should not happen if userspace parser was written correctly. */ if (f->wss.wc >= OSF_WSS_MAX) return false; /* Check options */ foptsize = 0; for (optnum = 0; optnum < f->opt_num; ++optnum) foptsize += f->opt[optnum].length; if (foptsize > MAX_IPOPTLEN || ctx->optsize > MAX_IPOPTLEN || ctx->optsize != foptsize) return false; check_WSS = f->wss.wc; for (optnum = 0; optnum < f->opt_num; ++optnum) { if (f->opt[optnum].kind == *ctx->optp) { __u32 len = f->opt[optnum].length; const __u8 *optend = ctx->optp + len; fmatch = FMATCH_OK; switch (*ctx->optp) { case OSFOPT_MSS: mss = ctx->optp[3]; mss <<= 8; mss |= ctx->optp[2]; mss = ntohs((__force __be16)mss); break; case OSFOPT_TS: break; } ctx->optp = optend; } else fmatch = FMATCH_OPT_WRONG; if (fmatch != FMATCH_OK) break; } if (fmatch != FMATCH_OPT_WRONG) { fmatch = FMATCH_WRONG; switch (check_WSS) { case OSF_WSS_PLAIN: if (f->wss.val == 0 || ctx->window == f->wss.val) fmatch = FMATCH_OK; break; case OSF_WSS_MSS: /* * Some smart modems decrease mangle MSS to * SMART_MSS_2, so we check standard, decreased * and the one provided in the fingerprint MSS * values. */ #define SMART_MSS_1 1460 #define SMART_MSS_2 1448 if (ctx->window == f->wss.val * mss || ctx->window == f->wss.val * SMART_MSS_1 || ctx->window == f->wss.val * SMART_MSS_2) fmatch = FMATCH_OK; break; case OSF_WSS_MTU: if (ctx->window == f->wss.val * (mss + 40) || ctx->window == f->wss.val * (SMART_MSS_1 + 40) || ctx->window == f->wss.val * (SMART_MSS_2 + 40)) fmatch = FMATCH_OK; break; case OSF_WSS_MODULO: if ((ctx->window % f->wss.val) == 0) fmatch = FMATCH_OK; break; } } if (fmatch != FMATCH_OK) ctx->optp = optpinit; return fmatch == FMATCH_OK; } static const struct tcphdr *nf_osf_hdr_ctx_init(struct nf_osf_hdr_ctx *ctx, const struct sk_buff *skb, const struct iphdr *ip, unsigned char *opts, struct tcphdr *_tcph) { const struct tcphdr *tcp; tcp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(struct tcphdr), _tcph); if (!tcp) return NULL; if (!tcp->syn) return NULL; ctx->totlen = ntohs(ip->tot_len); ctx->df = ntohs(ip->frag_off) & IP_DF; ctx->window = ntohs(tcp->window); if (tcp->doff * 4 > sizeof(struct tcphdr)) { ctx->optsize = tcp->doff * 4 - sizeof(struct tcphdr); ctx->optp = skb_header_pointer(skb, ip_hdrlen(skb) + sizeof(struct tcphdr), ctx->optsize, opts); if (!ctx->optp) return NULL; } return tcp; } bool nf_osf_match(const struct sk_buff *skb, u_int8_t family, int hooknum, struct net_device *in, struct net_device *out, const struct nf_osf_info *info, struct net *net, const struct list_head *nf_osf_fingers) { const struct iphdr *ip = ip_hdr(skb); const struct nf_osf_user_finger *f; unsigned char opts[MAX_IPOPTLEN]; const struct nf_osf_finger *kf; int fcount = 0, ttl_check; int fmatch = FMATCH_WRONG; struct nf_osf_hdr_ctx ctx; const struct tcphdr *tcp; struct tcphdr _tcph; memset(&ctx, 0, sizeof(ctx)); tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts, &_tcph); if (!tcp) return false; ttl_check = (info->flags & NF_OSF_TTL) ? info->ttl : 0; list_for_each_entry_rcu(kf, &nf_osf_fingers[ctx.df], finger_entry) { f = &kf->finger; if (!(info->flags & NF_OSF_LOG) && strcmp(info->genre, f->genre)) continue; if (!nf_osf_match_one(skb, f, ttl_check, &ctx)) continue; fmatch = FMATCH_OK; fcount++; if (info->flags & NF_OSF_LOG) nf_log_packet(net, family, hooknum, skb, in, out, NULL, "%s [%s:%s] : %pI4:%d -> %pI4:%d hops=%d\n", f->genre, f->version, f->subtype, &ip->saddr, ntohs(tcp->source), &ip->daddr, ntohs(tcp->dest), f->ttl - ip->ttl); if ((info->flags & NF_OSF_LOG) && info->loglevel == NF_OSF_LOGLEVEL_FIRST) break; } if (!fcount && (info->flags & NF_OSF_LOG)) nf_log_packet(net, family, hooknum, skb, in, out, NULL, "Remote OS is not known: %pI4:%u -> %pI4:%u\n", &ip->saddr, ntohs(tcp->source), &ip->daddr, ntohs(tcp->dest)); if (fcount) fmatch = FMATCH_OK; return fmatch == FMATCH_OK; } EXPORT_SYMBOL_GPL(nf_osf_match); bool nf_osf_find(const struct sk_buff *skb, const struct list_head *nf_osf_fingers, const int ttl_check, struct nf_osf_data *data) { const struct iphdr *ip = ip_hdr(skb); const struct nf_osf_user_finger *f; unsigned char opts[MAX_IPOPTLEN]; const struct nf_osf_finger *kf; struct nf_osf_hdr_ctx ctx; const struct tcphdr *tcp; struct tcphdr _tcph; bool found = false; memset(&ctx, 0, sizeof(ctx)); tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts, &_tcph); if (!tcp) return false; list_for_each_entry_rcu(kf, &nf_osf_fingers[ctx.df], finger_entry) { f = &kf->finger; if (!nf_osf_match_one(skb, f, ttl_check, &ctx)) continue; data->genre = f->genre; data->version = f->version; found = true; break; } return found; } EXPORT_SYMBOL_GPL(nf_osf_find); static const struct nla_policy nfnl_osf_policy[OSF_ATTR_MAX + 1] = { [OSF_ATTR_FINGER] = { .len = sizeof(struct nf_osf_user_finger) }, }; static int nfnl_osf_add_callback(struct sk_buff *skb, const struct nfnl_info *info, const struct nlattr * const osf_attrs[]) { struct nf_osf_user_finger *f; struct nf_osf_finger *kf = NULL, *sf; int err = 0; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (!osf_attrs[OSF_ATTR_FINGER]) return -EINVAL; if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) return -EINVAL; f = nla_data(osf_attrs[OSF_ATTR_FINGER]); if (f->opt_num > ARRAY_SIZE(f->opt)) return -EINVAL; if (!memchr(f->genre, 0, MAXGENRELEN) || !memchr(f->subtype, 0, MAXGENRELEN) || !memchr(f->version, 0, MAXGENRELEN)) return -EINVAL; kf = kmalloc(sizeof(struct nf_osf_finger), GFP_KERNEL); if (!kf) return -ENOMEM; memcpy(&kf->finger, f, sizeof(struct nf_osf_user_finger)); list_for_each_entry(sf, &nf_osf_fingers[!!f->df], finger_entry) { if (memcmp(&sf->finger, f, sizeof(struct nf_osf_user_finger))) continue; kfree(kf); kf = NULL; if (info->nlh->nlmsg_flags & NLM_F_EXCL) err = -EEXIST; break; } /* * We are protected by nfnl mutex. */ if (kf) list_add_tail_rcu(&kf->finger_entry, &nf_osf_fingers[!!f->df]); return err; } static int nfnl_osf_remove_callback(struct sk_buff *skb, const struct nfnl_info *info, const struct nlattr * const osf_attrs[]) { struct nf_osf_user_finger *f; struct nf_osf_finger *sf; int err = -ENOENT; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (!osf_attrs[OSF_ATTR_FINGER]) return -EINVAL; f = nla_data(osf_attrs[OSF_ATTR_FINGER]); list_for_each_entry(sf, &nf_osf_fingers[!!f->df], finger_entry) { if (memcmp(&sf->finger, f, sizeof(struct nf_osf_user_finger))) continue; /* * We are protected by nfnl mutex. */ list_del_rcu(&sf->finger_entry); kfree_rcu(sf, rcu_head); err = 0; break; } return err; } static const struct nfnl_callback nfnl_osf_callbacks[OSF_MSG_MAX] = { [OSF_MSG_ADD] = { .call = nfnl_osf_add_callback, .type = NFNL_CB_MUTEX, .attr_count = OSF_ATTR_MAX, .policy = nfnl_osf_policy, }, [OSF_MSG_REMOVE] = { .call = nfnl_osf_remove_callback, .type = NFNL_CB_MUTEX, .attr_count = OSF_ATTR_MAX, .policy = nfnl_osf_policy, }, }; static const struct nfnetlink_subsystem nfnl_osf_subsys = { .name = "osf", .subsys_id = NFNL_SUBSYS_OSF, .cb_count = OSF_MSG_MAX, .cb = nfnl_osf_callbacks, }; static int __init nfnl_osf_init(void) { int err = -EINVAL; int i; for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i) INIT_LIST_HEAD(&nf_osf_fingers[i]); err = nfnetlink_subsys_register(&nfnl_osf_subsys); if (err < 0) { pr_err("Failed to register OSF nsfnetlink helper (%d)\n", err); goto err_out_exit; } return 0; err_out_exit: return err; } static void __exit nfnl_osf_fini(void) { struct nf_osf_finger *f; int i; nfnetlink_subsys_unregister(&nfnl_osf_subsys); rcu_read_lock(); for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i) { list_for_each_entry_rcu(f, &nf_osf_fingers[i], finger_entry) { list_del_rcu(&f->finger_entry); kfree_rcu(f, rcu_head); } } rcu_read_unlock(); rcu_barrier(); } module_init(nfnl_osf_init); module_exit(nfnl_osf_fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Passive OS fingerprint matching"); MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_OSF);
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1