xref: /freebsd/sys/netinet/ip_var.h (revision 8aab44ce3b6a538d63b10c65f67c57b720ce01f7)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _NETINET_IP_VAR_H_
33 #define	_NETINET_IP_VAR_H_
34 
35 #include <sys/epoch.h>
36 #include <sys/queue.h>
37 #include <sys/types.h>
38 
39 #include <netinet/in.h>
40 
41 /*
42  * Overlay for ip header used by other protocols (tcp, udp).
43  */
44 struct ipovly {
45 	u_char	ih_x1[9];		/* (unused) */
46 	u_char	ih_pr;			/* protocol */
47 	u_short	ih_len;			/* protocol length */
48 	struct	in_addr ih_src;		/* source internet address */
49 	struct	in_addr ih_dst;		/* destination internet address */
50 } __packed;
51 
52 #ifdef _KERNEL
53 /*
54  * Ip reassembly queue structure.  Each fragment
55  * being reassembled is attached to one of these structures.
56  * They are timed out after net.inet.ip.fragttl seconds, and may also be
57  * reclaimed if memory becomes tight.
58  */
59 struct ipq {
60 	TAILQ_ENTRY(ipq) ipq_list;	/* to other reass headers */
61 	time_t	ipq_expire;		/* time_uptime when ipq expires */
62 	u_char	ipq_nfrags;		/* # frags in this packet */
63 	u_char	ipq_p;			/* protocol of this fragment */
64 	u_short	ipq_id;			/* sequence id for reassembly */
65 	int	ipq_maxoff;		/* total length of packet */
66 	struct mbuf *ipq_frags;		/* to ip headers of fragments */
67 	struct	in_addr ipq_src,ipq_dst;
68 	struct label *ipq_label;	/* MAC label */
69 };
70 #endif /* _KERNEL */
71 
72 /*
73  * Structure stored in mbuf in inpcb.ip_options
74  * and passed to ip_output when ip options are in use.
75  * The actual length of the options (including ipopt_dst)
76  * is in m_len.
77  */
78 #define MAX_IPOPTLEN	40
79 
80 struct ipoption {
81 	struct	in_addr ipopt_dst;	/* first-hop dst if source routed */
82 	char	ipopt_list[MAX_IPOPTLEN];	/* options proper */
83 };
84 
85 struct	ipstat {
86 	uint64_t ips_total;		/* total packets received */
87 	uint64_t ips_badsum;		/* checksum bad */
88 	uint64_t ips_tooshort;		/* packet too short */
89 	uint64_t ips_toosmall;		/* not enough data */
90 	uint64_t ips_badhlen;		/* ip header length < data size */
91 	uint64_t ips_badlen;		/* ip length < ip header length */
92 	uint64_t ips_fragments;		/* fragments received */
93 	uint64_t ips_fragdropped;	/* frags dropped (dups, out of space) */
94 	uint64_t ips_fragtimeout;	/* fragments timed out */
95 	uint64_t ips_forward;		/* packets forwarded */
96 	uint64_t ips_fastforward;	/* packets fast forwarded */
97 	uint64_t ips_cantforward;	/* packets rcvd for unreachable dest */
98 	uint64_t ips_redirectsent;	/* packets forwarded on same net */
99 	uint64_t ips_noproto;		/* unknown or unsupported protocol */
100 	uint64_t ips_delivered;		/* datagrams delivered to upper level*/
101 	uint64_t ips_localout;		/* total ip packets generated here */
102 	uint64_t ips_odropped;		/* lost packets due to nobufs, etc. */
103 	uint64_t ips_reassembled;	/* total packets reassembled ok */
104 	uint64_t ips_fragmented;	/* datagrams successfully fragmented */
105 	uint64_t ips_ofragments;	/* output fragments created */
106 	uint64_t ips_cantfrag;		/* don't fragment flag was set, etc. */
107 	uint64_t ips_badoptions;		/* error in option processing */
108 	uint64_t ips_noroute;		/* packets discarded due to no route */
109 	uint64_t ips_badvers;		/* ip version != 4 */
110 	uint64_t ips_rawout;		/* total raw ip packets generated */
111 	uint64_t ips_toolong;		/* ip length > max ip packet size */
112 	uint64_t ips_notmember;		/* multicasts for unregistered grps */
113 	uint64_t ips_nogif;		/* no match gif found */
114 	uint64_t ips_badaddr;		/* invalid address on header */
115 };
116 
117 #ifdef _KERNEL
118 
119 #include <sys/counter.h>
120 #include <net/vnet.h>
121 #include <netinet/in_kdtrace.h>
122 
123 VNET_PCPUSTAT_DECLARE(struct ipstat, ipstat);
124 /*
125  * In-kernel consumers can use these accessor macros directly to update
126  * stats.
127  */
128 #define IPSTAT_ADD(name, val)                                          \
129 	do {                                                           \
130 		MIB_SDT_PROBE1(ip, count, name, (val));                \
131 		VNET_PCPUSTAT_ADD(struct ipstat, ipstat, name, (val)); \
132 	} while (0)
133 #define IPSTAT_SUB(name, val) IPSTAT_ADD(name, -(val))
134 #define	IPSTAT_INC(name)	IPSTAT_ADD(name, 1)
135 #define	IPSTAT_DEC(name)	IPSTAT_SUB(name, 1)
136 
137 /*
138  * Kernel module consumers must use this accessor macro.
139  */
140 void	kmod_ipstat_inc(int statnum);
141 #define KMOD_IPSTAT_INC(name)                                          \
142 	do {                                                           \
143 		MIB_SDT_PROBE1(ip, count, name, 1);                    \
144 		kmod_ipstat_inc(                                       \
145 		    offsetof(struct ipstat, name) / sizeof(uint64_t)); \
146 	} while (0)
147 void kmod_ipstat_dec(int statnum);
148 #define KMOD_IPSTAT_DEC(name)                                          \
149 	do {                                                           \
150 		MIB_SDT_PROBE1(ip, count, name, -1);                   \
151 		kmod_ipstat_dec(                                       \
152 		    offsetof(struct ipstat, name) / sizeof(uint64_t)); \
153 	} while (0)
154 
155 /* flags passed to ip_output as last parameter */
156 #define	IP_FORWARDING		0x1		/* most of ip header exists */
157 #define	IP_RAWOUTPUT		0x2		/* raw ip header exists */
158 #define	IP_SENDONES		0x4		/* send all-ones broadcast */
159 #define	IP_SENDTOIF		0x8		/* send on specific ifnet */
160 #define IP_ROUTETOIF		SO_DONTROUTE	/* 0x10 bypass routing tables */
161 #define IP_ALLOWBROADCAST	SO_BROADCAST	/* 0x20 can send broadcast packets */
162 #define	IP_NODEFAULTFLOWID	0x40		/* Don't set the flowid from inp */
163 #define IP_NO_SND_TAG_RL	0x80		/* Don't send down the ratelimit tag */
164 
165 #ifdef __NO_STRICT_ALIGNMENT
166 #define IP_HDR_ALIGNED_P(ip)	1
167 #else
168 #define IP_HDR_ALIGNED_P(ip)	((((intptr_t) (ip)) & 3) == 0)
169 #endif
170 
171 struct ip;
172 struct inpcb;
173 struct route;
174 struct sockopt;
175 struct inpcbinfo;
176 struct ip_moptions;
177 
178 VNET_DECLARE(int, ip_defttl);			/* default IP ttl */
179 VNET_DECLARE(int, ipforwarding);		/* ip forwarding */
180 VNET_DECLARE(int, ipsendredirects);
181 #ifdef IPSTEALTH
182 VNET_DECLARE(int, ipstealth);			/* stealth forwarding */
183 #endif
184 VNET_DECLARE(struct socket *, ip_rsvpd);	/* reservation protocol daemon*/
185 VNET_DECLARE(int, rsvp_on);
186 VNET_DECLARE(int, drop_redirect);
187 VNET_DECLARE(int, ip_random_id);
188 
189 #define	V_ip_id			VNET(ip_id)
190 #define	V_ip_defttl		VNET(ip_defttl)
191 #define	V_ipforwarding		VNET(ipforwarding)
192 #define	V_ipsendredirects	VNET(ipsendredirects)
193 #ifdef IPSTEALTH
194 #define	V_ipstealth		VNET(ipstealth)
195 #endif
196 #define	V_ip_rsvpd		VNET(ip_rsvpd)
197 #define	V_rsvp_on		VNET(rsvp_on)
198 #define	V_drop_redirect		VNET(drop_redirect)
199 #define	V_ip_random_id		VNET(ip_random_id)
200 
201 void	inp_freemoptions(struct ip_moptions *);
202 int	inp_getmoptions(struct inpcb *, struct sockopt *);
203 int	inp_setmoptions(struct inpcb *, struct sockopt *);
204 
205 int	ip_ctloutput(struct socket *, struct sockopt *sopt);
206 int	ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
207 	    u_long if_hwassist_flags);
208 void	ip_forward(struct mbuf *m, int srcrt);
209 int	ip_output(struct mbuf *,
210 	    struct mbuf *, struct route *, int, struct ip_moptions *,
211 	    struct inpcb *);
212 struct mbuf *
213 	ip_reass(struct mbuf *);
214 void	ip_savecontrol(struct inpcb *, struct mbuf **, struct ip *,
215 	    struct mbuf *);
216 void	ip_fillid(struct ip *, bool);
217 int	rip_ctloutput(struct socket *, struct sockopt *);
218 int	ipip_input(struct mbuf **, int *, int);
219 int	rsvp_input(struct mbuf **, int *, int);
220 
221 int	ip_rsvp_init(struct socket *);
222 int	ip_rsvp_done(void);
223 
224 typedef int	ipproto_input_t(struct mbuf **, int *, int);
225 struct icmp;
226 typedef void	ipproto_ctlinput_t(struct icmp *);
227 int	ipproto_register(uint8_t, ipproto_input_t, ipproto_ctlinput_t);
228 int	ipproto_unregister(uint8_t);
229 #define	IPPROTO_REGISTER(prot, input, ctl)	do {			\
230 	int error __diagused;						\
231 	error = ipproto_register(prot, input, ctl);			\
232 	MPASS(error == 0);						\
233 } while (0)
234 
235 ipproto_input_t		rip_input;
236 ipproto_ctlinput_t	rip_ctlinput;
237 
238 VNET_DECLARE(struct pfil_head *, inet_pfil_head);
239 #define	V_inet_pfil_head	VNET(inet_pfil_head)
240 #define	PFIL_INET_NAME		"inet"
241 
242 VNET_DECLARE(struct pfil_head *, inet_local_pfil_head);
243 #define	V_inet_local_pfil_head	VNET(inet_local_pfil_head)
244 #define	PFIL_INET_LOCAL_NAME	"inet-local"
245 
246 void	in_delayed_cksum(struct mbuf *m);
247 void	in_delayed_cksum_o(struct mbuf *m, uint16_t o);
248 
249 /* Hooks for ipfw, dummynet, divert etc. Most are declared in raw_ip.c */
250 /*
251  * Reference to an ipfw or packet filter rule that can be carried
252  * outside critical sections.
253  * A rule is identified by rulenum:rule_id which is ordered.
254  * In version chain_id the rule can be found in slot 'slot', so
255  * we don't need a lookup if chain_id == chain->id.
256  *
257  * On exit from the firewall this structure refers to the rule after
258  * the matching one (slot points to the new rule; rulenum:rule_id-1
259  * is the matching rule), and additional info (e.g. info often contains
260  * the insn argument or tablearg in the low 16 bits, in host format).
261  * On entry, the structure is valid if slot>0, and refers to the starting
262  * rules. 'info' contains the reason for reinject, e.g. divert port,
263  * divert direction, and so on.
264  *
265  * Packet Mark is an analogue to ipfw tags with O(1) lookup from mbuf while
266  * regular tags require a single-linked list traversal. Mark is a 32-bit
267  * number that can be looked up in a table [with 'number' table-type], matched
268  * or compared with a number with optional mask applied before comparison.
269  * Having generic nature, Mark can be used in a variety of needs.
270  * For example, it could be used as a security group: mark will hold a
271  * security group id and represent a group of packet flows that shares same
272  * access control policy.
273  * O_MASK opcode can match mark value bitwise so one can build a hierarchical
274  * model designating different meanings for a bit range(s).
275  */
276 struct ipfw_rule_ref {
277 /* struct m_tag spans 24 bytes above this point, see mbuf_tags(9) */
278 	/* spare space just to be save in case struct m_tag grows */
279 /* -- 32 bytes -- */
280 	uint32_t	slot;		/* slot for matching rule	*/
281 	uint32_t	rulenum;	/* matching rule number		*/
282 	uint32_t	rule_id;	/* matching rule id		*/
283 	uint32_t	chain_id;	/* ruleset id			*/
284 	uint32_t	info;		/* see below			*/
285 	uint32_t	pkt_mark;	/* packet mark			*/
286 	uint32_t	spare[2];
287 /* -- 64 bytes -- */
288 };
289 
290 enum {
291 	IPFW_INFO_MASK	= 0x0000ffff,
292 	IPFW_INFO_OUT	= 0x00000000,	/* outgoing, just for convenience */
293 	IPFW_INFO_IN	= 0x80000000,	/* incoming, overloads dir */
294 	IPFW_ONEPASS	= 0x40000000,	/* One-pass, do not reinject */
295 	IPFW_IS_MASK	= 0x30000000,	/* which source ? */
296 	IPFW_IS_DIVERT	= 0x20000000,
297 	IPFW_IS_DUMMYNET =0x10000000,
298 	IPFW_IS_PIPE	= 0x08000000,	/* pipe=1, queue = 0 */
299 };
300 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
301 #define MTAG_IPFW_RULE	1262273568	/* rule reference */
302 #define	MTAG_IPFW_CALL	1308397630	/* call stack */
303 
304 struct ip_fw_args;
305 typedef int	(*ip_fw_ctl_ptr_t)(struct sockopt *);
306 VNET_DECLARE(ip_fw_ctl_ptr_t, ip_fw_ctl_ptr);
307 #define	V_ip_fw_ctl_ptr		VNET(ip_fw_ctl_ptr)
308 
309 /* Divert hooks. */
310 extern void	(*ip_divert_ptr)(struct mbuf *m, uint64_t id, bool incoming);
311 /* ng_ipfw hooks -- XXX make it the same as divert and dummynet */
312 extern int	(*ng_ipfw_input_p)(struct mbuf **, struct ip_fw_args *, bool);
313 extern int	(*ip_dn_ctl_ptr)(struct sockopt *);
314 extern int	(*ip_dn_io_ptr)(struct mbuf **, struct ip_fw_args *);
315 
316 /* pf specific mtag for divert(4) support */
__enum_uint8_decl(pf_mtag_dir)317 __enum_uint8_decl(pf_mtag_dir) {
318 	PF_DIVERT_MTAG_DIR_IN = 1,
319 	PF_DIVERT_MTAG_DIR_OUT = 2
320 };
321 struct pf_divert_mtag {
322 	__enum_uint8(pf_mtag_dir) idir;		/* initial pkt direction */
323 	union {
324 		__enum_uint8(pf_mtag_dir) ndir;	/* new dir after re-enter */
325 		uint16_t port;			/* initial divert(4) port */
326 	};
327 };
328 #define MTAG_PF_DIVERT	1262273569
329 
330 #endif /* _KERNEL */
331 
332 #endif /* !_NETINET_IP_VAR_H_ */
333