This source file includes following definitions.
- trace_fill_id
- trace_fill_header
- nf_trace_fill_ll_header
- nf_trace_fill_dev_info
- nf_trace_fill_pkt_info
- nf_trace_fill_rule_info
- nft_trace_have_verdict_chain
- nft_trace_notify
- nft_trace_init
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6
7 #include <linux/module.h>
8 #include <linux/static_key.h>
9 #include <linux/hash.h>
10 #include <linux/jhash.h>
11 #include <linux/if_vlan.h>
12 #include <linux/init.h>
13 #include <linux/skbuff.h>
14 #include <linux/netlink.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter/nfnetlink.h>
17 #include <linux/netfilter/nf_tables.h>
18 #include <net/netfilter/nf_tables_core.h>
19 #include <net/netfilter/nf_tables.h>
20
21 #define NFT_TRACETYPE_LL_HSIZE 20
22 #define NFT_TRACETYPE_NETWORK_HSIZE 40
23 #define NFT_TRACETYPE_TRANSPORT_HSIZE 20
24
25 DEFINE_STATIC_KEY_FALSE(nft_trace_enabled);
26 EXPORT_SYMBOL_GPL(nft_trace_enabled);
27
28 static int trace_fill_id(struct sk_buff *nlskb, struct sk_buff *skb)
29 {
30 __be32 id;
31
32
33
34
35
36
37
38 id = (__be32)jhash_2words(hash32_ptr(skb), skb_get_hash(skb),
39 skb->skb_iif);
40
41 return nla_put_be32(nlskb, NFTA_TRACE_ID, id);
42 }
43
44 static int trace_fill_header(struct sk_buff *nlskb, u16 type,
45 const struct sk_buff *skb,
46 int off, unsigned int len)
47 {
48 struct nlattr *nla;
49
50 if (len == 0)
51 return 0;
52
53 nla = nla_reserve(nlskb, type, len);
54 if (!nla || skb_copy_bits(skb, off, nla_data(nla), len))
55 return -1;
56
57 return 0;
58 }
59
60 static int nf_trace_fill_ll_header(struct sk_buff *nlskb,
61 const struct sk_buff *skb)
62 {
63 struct vlan_ethhdr veth;
64 int off;
65
66 BUILD_BUG_ON(sizeof(veth) > NFT_TRACETYPE_LL_HSIZE);
67
68 off = skb_mac_header(skb) - skb->data;
69 if (off != -ETH_HLEN)
70 return -1;
71
72 if (skb_copy_bits(skb, off, &veth, ETH_HLEN))
73 return -1;
74
75 veth.h_vlan_proto = skb->vlan_proto;
76 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
77 veth.h_vlan_encapsulated_proto = skb->protocol;
78
79 return nla_put(nlskb, NFTA_TRACE_LL_HEADER, sizeof(veth), &veth);
80 }
81
82 static int nf_trace_fill_dev_info(struct sk_buff *nlskb,
83 const struct net_device *indev,
84 const struct net_device *outdev)
85 {
86 if (indev) {
87 if (nla_put_be32(nlskb, NFTA_TRACE_IIF,
88 htonl(indev->ifindex)))
89 return -1;
90
91 if (nla_put_be16(nlskb, NFTA_TRACE_IIFTYPE,
92 htons(indev->type)))
93 return -1;
94 }
95
96 if (outdev) {
97 if (nla_put_be32(nlskb, NFTA_TRACE_OIF,
98 htonl(outdev->ifindex)))
99 return -1;
100
101 if (nla_put_be16(nlskb, NFTA_TRACE_OIFTYPE,
102 htons(outdev->type)))
103 return -1;
104 }
105
106 return 0;
107 }
108
109 static int nf_trace_fill_pkt_info(struct sk_buff *nlskb,
110 const struct nft_pktinfo *pkt)
111 {
112 const struct sk_buff *skb = pkt->skb;
113 int off = skb_network_offset(skb);
114 unsigned int len, nh_end;
115
116 nh_end = pkt->tprot_set ? pkt->xt.thoff : skb->len;
117 len = min_t(unsigned int, nh_end - skb_network_offset(skb),
118 NFT_TRACETYPE_NETWORK_HSIZE);
119 if (trace_fill_header(nlskb, NFTA_TRACE_NETWORK_HEADER, skb, off, len))
120 return -1;
121
122 if (pkt->tprot_set) {
123 len = min_t(unsigned int, skb->len - pkt->xt.thoff,
124 NFT_TRACETYPE_TRANSPORT_HSIZE);
125 if (trace_fill_header(nlskb, NFTA_TRACE_TRANSPORT_HEADER, skb,
126 pkt->xt.thoff, len))
127 return -1;
128 }
129
130 if (!skb_mac_header_was_set(skb))
131 return 0;
132
133 if (skb_vlan_tag_get(skb))
134 return nf_trace_fill_ll_header(nlskb, skb);
135
136 off = skb_mac_header(skb) - skb->data;
137 len = min_t(unsigned int, -off, NFT_TRACETYPE_LL_HSIZE);
138 return trace_fill_header(nlskb, NFTA_TRACE_LL_HEADER,
139 skb, off, len);
140 }
141
142 static int nf_trace_fill_rule_info(struct sk_buff *nlskb,
143 const struct nft_traceinfo *info)
144 {
145 if (!info->rule)
146 return 0;
147
148
149
150
151
152
153 if (info->type == NFT_TRACETYPE_RETURN &&
154 info->verdict->code == NFT_CONTINUE)
155 return 0;
156
157 return nla_put_be64(nlskb, NFTA_TRACE_RULE_HANDLE,
158 cpu_to_be64(info->rule->handle),
159 NFTA_TRACE_PAD);
160 }
161
162 static bool nft_trace_have_verdict_chain(struct nft_traceinfo *info)
163 {
164 switch (info->type) {
165 case NFT_TRACETYPE_RETURN:
166 case NFT_TRACETYPE_RULE:
167 break;
168 default:
169 return false;
170 }
171
172 switch (info->verdict->code) {
173 case NFT_JUMP:
174 case NFT_GOTO:
175 break;
176 default:
177 return false;
178 }
179
180 return true;
181 }
182
183 void nft_trace_notify(struct nft_traceinfo *info)
184 {
185 const struct nft_pktinfo *pkt = info->pkt;
186 struct nfgenmsg *nfmsg;
187 struct nlmsghdr *nlh;
188 struct sk_buff *skb;
189 unsigned int size;
190 u16 event;
191
192 if (!nfnetlink_has_listeners(nft_net(pkt), NFNLGRP_NFTRACE))
193 return;
194
195 size = nlmsg_total_size(sizeof(struct nfgenmsg)) +
196 nla_total_size(strlen(info->chain->table->name)) +
197 nla_total_size(strlen(info->chain->name)) +
198 nla_total_size_64bit(sizeof(__be64)) +
199 nla_total_size(sizeof(__be32)) +
200 nla_total_size(0) +
201 nla_total_size(sizeof(u32)) +
202 nla_total_size(sizeof(u32)) +
203 nla_total_size(NFT_TRACETYPE_LL_HSIZE) +
204 nla_total_size(NFT_TRACETYPE_NETWORK_HSIZE) +
205 nla_total_size(NFT_TRACETYPE_TRANSPORT_HSIZE) +
206 nla_total_size(sizeof(u32)) +
207 nla_total_size(sizeof(__be16)) +
208 nla_total_size(sizeof(u32)) +
209 nla_total_size(sizeof(__be16)) +
210 nla_total_size(sizeof(u32)) +
211 nla_total_size(sizeof(u32)) +
212 nla_total_size(sizeof(u32));
213
214 if (nft_trace_have_verdict_chain(info))
215 size += nla_total_size(strlen(info->verdict->chain->name));
216
217 skb = nlmsg_new(size, GFP_ATOMIC);
218 if (!skb)
219 return;
220
221 event = nfnl_msg_type(NFNL_SUBSYS_NFTABLES, NFT_MSG_TRACE);
222 nlh = nlmsg_put(skb, 0, 0, event, sizeof(struct nfgenmsg), 0);
223 if (!nlh)
224 goto nla_put_failure;
225
226 nfmsg = nlmsg_data(nlh);
227 nfmsg->nfgen_family = info->basechain->type->family;
228 nfmsg->version = NFNETLINK_V0;
229 nfmsg->res_id = 0;
230
231 if (nla_put_be32(skb, NFTA_TRACE_NFPROTO, htonl(nft_pf(pkt))))
232 goto nla_put_failure;
233
234 if (nla_put_be32(skb, NFTA_TRACE_TYPE, htonl(info->type)))
235 goto nla_put_failure;
236
237 if (trace_fill_id(skb, pkt->skb))
238 goto nla_put_failure;
239
240 if (nla_put_string(skb, NFTA_TRACE_CHAIN, info->chain->name))
241 goto nla_put_failure;
242
243 if (nla_put_string(skb, NFTA_TRACE_TABLE, info->chain->table->name))
244 goto nla_put_failure;
245
246 if (nf_trace_fill_rule_info(skb, info))
247 goto nla_put_failure;
248
249 switch (info->type) {
250 case NFT_TRACETYPE_UNSPEC:
251 case __NFT_TRACETYPE_MAX:
252 break;
253 case NFT_TRACETYPE_RETURN:
254 case NFT_TRACETYPE_RULE:
255 if (nft_verdict_dump(skb, NFTA_TRACE_VERDICT, info->verdict))
256 goto nla_put_failure;
257 break;
258 case NFT_TRACETYPE_POLICY:
259 if (nla_put_be32(skb, NFTA_TRACE_POLICY,
260 htonl(info->basechain->policy)))
261 goto nla_put_failure;
262 break;
263 }
264
265 if (pkt->skb->mark &&
266 nla_put_be32(skb, NFTA_TRACE_MARK, htonl(pkt->skb->mark)))
267 goto nla_put_failure;
268
269 if (!info->packet_dumped) {
270 if (nf_trace_fill_dev_info(skb, nft_in(pkt), nft_out(pkt)))
271 goto nla_put_failure;
272
273 if (nf_trace_fill_pkt_info(skb, pkt))
274 goto nla_put_failure;
275 info->packet_dumped = true;
276 }
277
278 nlmsg_end(skb, nlh);
279 nfnetlink_send(skb, nft_net(pkt), 0, NFNLGRP_NFTRACE, 0, GFP_ATOMIC);
280 return;
281
282 nla_put_failure:
283 WARN_ON_ONCE(1);
284 kfree_skb(skb);
285 }
286
287 void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
288 const struct nft_verdict *verdict,
289 const struct nft_chain *chain)
290 {
291 info->basechain = nft_base_chain(chain);
292 info->trace = true;
293 info->packet_dumped = false;
294 info->pkt = pkt;
295 info->verdict = verdict;
296 }