xref: /freebsd/sys/netinet/ip_var.h (revision 7a7741af18d6c8a804cc643cb7ecda9d730c6aa6)
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 };
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 #if defined(_NETINET_IN_VAR_H_) && defined(_KERNEL)
86 /*
87  * Structure attached to inpcb.ip_moptions and
88  * passed to ip_output when IP multicast options are in use.
89  * This structure is lazy-allocated.
90  */
91 struct ip_moptions {
92 	struct	ifnet *imo_multicast_ifp; /* ifp for outgoing multicasts */
93 	struct in_addr imo_multicast_addr; /* ifindex/addr on MULTICAST_IF */
94 	u_long	imo_multicast_vif;	/* vif num outgoing multicasts */
95 	u_char	imo_multicast_ttl;	/* TTL for outgoing multicasts */
96 	u_char	imo_multicast_loop;	/* 1 => hear sends if a member */
97 	struct ip_mfilter_head imo_head; /* group membership list */
98 };
99 #else
100 struct ip_moptions;
101 #endif
102 
103 struct	ipstat {
104 	uint64_t ips_total;		/* total packets received */
105 	uint64_t ips_badsum;		/* checksum bad */
106 	uint64_t ips_tooshort;		/* packet too short */
107 	uint64_t ips_toosmall;		/* not enough data */
108 	uint64_t ips_badhlen;		/* ip header length < data size */
109 	uint64_t ips_badlen;		/* ip length < ip header length */
110 	uint64_t ips_fragments;		/* fragments received */
111 	uint64_t ips_fragdropped;	/* frags dropped (dups, out of space) */
112 	uint64_t ips_fragtimeout;	/* fragments timed out */
113 	uint64_t ips_forward;		/* packets forwarded */
114 	uint64_t ips_fastforward;	/* packets fast forwarded */
115 	uint64_t ips_cantforward;	/* packets rcvd for unreachable dest */
116 	uint64_t ips_redirectsent;	/* packets forwarded on same net */
117 	uint64_t ips_noproto;		/* unknown or unsupported protocol */
118 	uint64_t ips_delivered;		/* datagrams delivered to upper level*/
119 	uint64_t ips_localout;		/* total ip packets generated here */
120 	uint64_t ips_odropped;		/* lost packets due to nobufs, etc. */
121 	uint64_t ips_reassembled;	/* total packets reassembled ok */
122 	uint64_t ips_fragmented;	/* datagrams successfully fragmented */
123 	uint64_t ips_ofragments;	/* output fragments created */
124 	uint64_t ips_cantfrag;		/* don't fragment flag was set, etc. */
125 	uint64_t ips_badoptions;		/* error in option processing */
126 	uint64_t ips_noroute;		/* packets discarded due to no route */
127 	uint64_t ips_badvers;		/* ip version != 4 */
128 	uint64_t ips_rawout;		/* total raw ip packets generated */
129 	uint64_t ips_toolong;		/* ip length > max ip packet size */
130 	uint64_t ips_notmember;		/* multicasts for unregistered grps */
131 	uint64_t ips_nogif;		/* no match gif found */
132 	uint64_t ips_badaddr;		/* invalid address on header */
133 };
134 
135 #ifdef _KERNEL
136 
137 #include <sys/counter.h>
138 #include <net/vnet.h>
139 #include <netinet/in_kdtrace.h>
140 
141 VNET_PCPUSTAT_DECLARE(struct ipstat, ipstat);
142 /*
143  * In-kernel consumers can use these accessor macros directly to update
144  * stats.
145  */
146 #define IPSTAT_ADD(name, val)                                          \
147 	do {                                                           \
148 		MIB_SDT_PROBE1(ip, count, name, (val));                \
149 		VNET_PCPUSTAT_ADD(struct ipstat, ipstat, name, (val)); \
150 	} while (0)
151 #define IPSTAT_SUB(name, val) IPSTAT_ADD(name, -(val))
152 #define	IPSTAT_INC(name)	IPSTAT_ADD(name, 1)
153 #define	IPSTAT_DEC(name)	IPSTAT_SUB(name, 1)
154 
155 /*
156  * Kernel module consumers must use this accessor macro.
157  */
158 void	kmod_ipstat_inc(int statnum);
159 #define KMOD_IPSTAT_INC(name)                                          \
160 	do {                                                           \
161 		MIB_SDT_PROBE1(ip, count, name, 1);                    \
162 		kmod_ipstat_inc(                                       \
163 		    offsetof(struct ipstat, name) / sizeof(uint64_t)); \
164 	} while (0)
165 void kmod_ipstat_dec(int statnum);
166 #define KMOD_IPSTAT_DEC(name)                                          \
167 	do {                                                           \
168 		MIB_SDT_PROBE1(ip, count, name, -1);                   \
169 		kmod_ipstat_dec(                                       \
170 		    offsetof(struct ipstat, name) / sizeof(uint64_t)); \
171 	} while (0)
172 
173 /* flags passed to ip_output as last parameter */
174 #define	IP_FORWARDING		0x1		/* most of ip header exists */
175 #define	IP_RAWOUTPUT		0x2		/* raw ip header exists */
176 #define	IP_SENDONES		0x4		/* send all-ones broadcast */
177 #define	IP_SENDTOIF		0x8		/* send on specific ifnet */
178 #define IP_ROUTETOIF		SO_DONTROUTE	/* 0x10 bypass routing tables */
179 #define IP_ALLOWBROADCAST	SO_BROADCAST	/* 0x20 can send broadcast packets */
180 #define	IP_NODEFAULTFLOWID	0x40		/* Don't set the flowid from inp */
181 #define IP_NO_SND_TAG_RL	0x80		/* Don't send down the ratelimit tag */
182 
183 #ifdef __NO_STRICT_ALIGNMENT
184 #define IP_HDR_ALIGNED_P(ip)	1
185 #else
186 #define IP_HDR_ALIGNED_P(ip)	((((intptr_t) (ip)) & 3) == 0)
187 #endif
188 
189 struct ip;
190 struct inpcb;
191 struct route;
192 struct sockopt;
193 struct inpcbinfo;
194 
195 VNET_DECLARE(int, ip_defttl);			/* default IP ttl */
196 VNET_DECLARE(int, ipforwarding);		/* ip forwarding */
197 VNET_DECLARE(int, ipsendredirects);
198 #ifdef IPSTEALTH
199 VNET_DECLARE(int, ipstealth);			/* stealth forwarding */
200 #endif
201 VNET_DECLARE(struct socket *, ip_rsvpd);	/* reservation protocol daemon*/
202 VNET_DECLARE(struct socket *, ip_mrouter);	/* multicast routing daemon */
203 extern int	(*legal_vif_num)(int);
204 extern u_long	(*ip_mcast_src)(int);
205 VNET_DECLARE(int, rsvp_on);
206 VNET_DECLARE(int, drop_redirect);
207 
208 #define	V_ip_id			VNET(ip_id)
209 #define	V_ip_defttl		VNET(ip_defttl)
210 #define	V_ipforwarding		VNET(ipforwarding)
211 #define	V_ipsendredirects	VNET(ipsendredirects)
212 #ifdef IPSTEALTH
213 #define	V_ipstealth		VNET(ipstealth)
214 #endif
215 #define	V_ip_rsvpd		VNET(ip_rsvpd)
216 #define	V_ip_mrouter		VNET(ip_mrouter)
217 #define	V_rsvp_on		VNET(rsvp_on)
218 #define	V_drop_redirect		VNET(drop_redirect)
219 
220 void	inp_freemoptions(struct ip_moptions *);
221 int	inp_getmoptions(struct inpcb *, struct sockopt *);
222 int	inp_setmoptions(struct inpcb *, struct sockopt *);
223 
224 int	ip_ctloutput(struct socket *, struct sockopt *sopt);
225 int	ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
226 	    u_long if_hwassist_flags);
227 void	ip_forward(struct mbuf *m, int srcrt);
228 extern int
229 	(*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
230 	    struct ip_moptions *);
231 int	ip_output(struct mbuf *,
232 	    struct mbuf *, struct route *, int, struct ip_moptions *,
233 	    struct inpcb *);
234 struct mbuf *
235 	ip_reass(struct mbuf *);
236 void	ip_savecontrol(struct inpcb *, struct mbuf **, struct ip *,
237 	    struct mbuf *);
238 void	ip_fillid(struct ip *);
239 int	rip_ctloutput(struct socket *, struct sockopt *);
240 int	ipip_input(struct mbuf **, int *, int);
241 int	rsvp_input(struct mbuf **, int *, int);
242 
243 int	ip_rsvp_init(struct socket *);
244 int	ip_rsvp_done(void);
245 extern int	(*ip_rsvp_vif)(struct socket *, struct sockopt *);
246 extern void	(*ip_rsvp_force_done)(struct socket *);
247 extern int	(*rsvp_input_p)(struct mbuf **, int *, int);
248 
249 typedef int	ipproto_input_t(struct mbuf **, int *, int);
250 struct icmp;
251 typedef void	ipproto_ctlinput_t(struct icmp *);
252 int	ipproto_register(uint8_t, ipproto_input_t, ipproto_ctlinput_t);
253 int	ipproto_unregister(uint8_t);
254 #define	IPPROTO_REGISTER(prot, input, ctl)	do {			\
255 	int error __diagused;						\
256 	error = ipproto_register(prot, input, ctl);			\
257 	MPASS(error == 0);						\
258 } while (0)
259 
260 ipproto_input_t		rip_input;
261 ipproto_ctlinput_t	rip_ctlinput;
262 
263 VNET_DECLARE(struct pfil_head *, inet_pfil_head);
264 #define	V_inet_pfil_head	VNET(inet_pfil_head)
265 #define	PFIL_INET_NAME		"inet"
266 
267 VNET_DECLARE(struct pfil_head *, inet_local_pfil_head);
268 #define	V_inet_local_pfil_head	VNET(inet_local_pfil_head)
269 #define	PFIL_INET_LOCAL_NAME	"inet-local"
270 
271 void	in_delayed_cksum(struct mbuf *m);
272 
273 /* Hooks for ipfw, dummynet, divert etc. Most are declared in raw_ip.c */
274 /*
275  * Reference to an ipfw or packet filter rule that can be carried
276  * outside critical sections.
277  * A rule is identified by rulenum:rule_id which is ordered.
278  * In version chain_id the rule can be found in slot 'slot', so
279  * we don't need a lookup if chain_id == chain->id.
280  *
281  * On exit from the firewall this structure refers to the rule after
282  * the matching one (slot points to the new rule; rulenum:rule_id-1
283  * is the matching rule), and additional info (e.g. info often contains
284  * the insn argument or tablearg in the low 16 bits, in host format).
285  * On entry, the structure is valid if slot>0, and refers to the starting
286  * rules. 'info' contains the reason for reinject, e.g. divert port,
287  * divert direction, and so on.
288  *
289  * Packet Mark is an analogue to ipfw tags with O(1) lookup from mbuf while
290  * regular tags require a single-linked list traversal. Mark is a 32-bit
291  * number that can be looked up in a table [with 'number' table-type], matched
292  * or compared with a number with optional mask applied before comparison.
293  * Having generic nature, Mark can be used in a variety of needs.
294  * For example, it could be used as a security group: mark will hold a
295  * security group id and represent a group of packet flows that shares same
296  * access control policy.
297  * O_MASK opcode can match mark value bitwise so one can build a hierarchical
298  * model designating different meanings for a bit range(s).
299  */
300 struct ipfw_rule_ref {
301 /* struct m_tag spans 24 bytes above this point, see mbuf_tags(9) */
302 	/* spare space just to be save in case struct m_tag grows */
303 /* -- 32 bytes -- */
304 	uint32_t	slot;		/* slot for matching rule	*/
305 	uint32_t	rulenum;	/* matching rule number		*/
306 	uint32_t	rule_id;	/* matching rule id		*/
307 	uint32_t	chain_id;	/* ruleset id			*/
308 	uint32_t	info;		/* see below			*/
309 	uint32_t	pkt_mark;	/* packet mark			*/
310 	uint32_t	spare[2];
311 /* -- 64 bytes -- */
312 };
313 
314 enum {
315 	IPFW_INFO_MASK	= 0x0000ffff,
316 	IPFW_INFO_OUT	= 0x00000000,	/* outgoing, just for convenience */
317 	IPFW_INFO_IN	= 0x80000000,	/* incoming, overloads dir */
318 	IPFW_ONEPASS	= 0x40000000,	/* One-pass, do not reinject */
319 	IPFW_IS_MASK	= 0x30000000,	/* which source ? */
320 	IPFW_IS_DIVERT	= 0x20000000,
321 	IPFW_IS_DUMMYNET =0x10000000,
322 	IPFW_IS_PIPE	= 0x08000000,	/* pipe=1, queue = 0 */
323 };
324 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
325 #define MTAG_IPFW_RULE	1262273568	/* rule reference */
326 #define	MTAG_IPFW_CALL	1308397630	/* call stack */
327 
328 struct ip_fw_args;
329 typedef int	(*ip_fw_ctl_ptr_t)(struct sockopt *);
330 VNET_DECLARE(ip_fw_ctl_ptr_t, ip_fw_ctl_ptr);
331 #define	V_ip_fw_ctl_ptr		VNET(ip_fw_ctl_ptr)
332 
333 /* Divert hooks. */
334 extern void	(*ip_divert_ptr)(struct mbuf *m, bool incoming);
335 /* ng_ipfw hooks -- XXX make it the same as divert and dummynet */
336 extern int	(*ng_ipfw_input_p)(struct mbuf **, struct ip_fw_args *, bool);
337 extern int	(*ip_dn_ctl_ptr)(struct sockopt *);
338 extern int	(*ip_dn_io_ptr)(struct mbuf **, struct ip_fw_args *);
339 
340 /* pf specific mtag for divert(4) support */
341 __enum_uint8_decl(pf_mtag_dir) {
342 	PF_DIVERT_MTAG_DIR_IN = 1,
343 	PF_DIVERT_MTAG_DIR_OUT = 2
344 };
345 struct pf_divert_mtag {
346 	__enum_uint8(pf_mtag_dir) idir;		/* initial pkt direction */
347 	union {
348 		__enum_uint8(pf_mtag_dir) ndir;	/* new dir after re-enter */
349 		uint16_t port;			/* initial divert(4) port */
350 	};
351 };
352 #define MTAG_PF_DIVERT	1262273569
353 
354 #endif /* _KERNEL */
355 
356 #endif /* !_NETINET_IP_VAR_H_ */
357