xref: /freebsd/sys/netinet/ip_var.h (revision 70703aa922b41faedfd72211633884bb580ceeac)
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 VNET_DECLARE(int, ip_random_id);
208 
209 #define	V_ip_id			VNET(ip_id)
210 #define	V_ip_defttl		VNET(ip_defttl)
211 #define	V_ipforwarding		VNET(ipforwarding)
212 #define	V_ipsendredirects	VNET(ipsendredirects)
213 #ifdef IPSTEALTH
214 #define	V_ipstealth		VNET(ipstealth)
215 #endif
216 #define	V_ip_rsvpd		VNET(ip_rsvpd)
217 #define	V_ip_mrouter		VNET(ip_mrouter)
218 #define	V_rsvp_on		VNET(rsvp_on)
219 #define	V_drop_redirect		VNET(drop_redirect)
220 #define	V_ip_random_id		VNET(ip_random_id)
221 
222 void	inp_freemoptions(struct ip_moptions *);
223 int	inp_getmoptions(struct inpcb *, struct sockopt *);
224 int	inp_setmoptions(struct inpcb *, struct sockopt *);
225 
226 int	ip_ctloutput(struct socket *, struct sockopt *sopt);
227 int	ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
228 	    u_long if_hwassist_flags);
229 void	ip_forward(struct mbuf *m, int srcrt);
230 extern int
231 	(*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
232 	    struct ip_moptions *);
233 int	ip_output(struct mbuf *,
234 	    struct mbuf *, struct route *, int, struct ip_moptions *,
235 	    struct inpcb *);
236 struct mbuf *
237 	ip_reass(struct mbuf *);
238 void	ip_savecontrol(struct inpcb *, struct mbuf **, struct ip *,
239 	    struct mbuf *);
240 void	ip_fillid(struct ip *, bool);
241 int	rip_ctloutput(struct socket *, struct sockopt *);
242 int	ipip_input(struct mbuf **, int *, int);
243 int	rsvp_input(struct mbuf **, int *, int);
244 
245 int	ip_rsvp_init(struct socket *);
246 int	ip_rsvp_done(void);
247 extern int	(*ip_rsvp_vif)(struct socket *, struct sockopt *);
248 extern void	(*ip_rsvp_force_done)(struct socket *);
249 extern int	(*rsvp_input_p)(struct mbuf **, int *, int);
250 
251 typedef int	ipproto_input_t(struct mbuf **, int *, int);
252 struct icmp;
253 typedef void	ipproto_ctlinput_t(struct icmp *);
254 int	ipproto_register(uint8_t, ipproto_input_t, ipproto_ctlinput_t);
255 int	ipproto_unregister(uint8_t);
256 #define	IPPROTO_REGISTER(prot, input, ctl)	do {			\
257 	int error __diagused;						\
258 	error = ipproto_register(prot, input, ctl);			\
259 	MPASS(error == 0);						\
260 } while (0)
261 
262 ipproto_input_t		rip_input;
263 ipproto_ctlinput_t	rip_ctlinput;
264 
265 VNET_DECLARE(struct pfil_head *, inet_pfil_head);
266 #define	V_inet_pfil_head	VNET(inet_pfil_head)
267 #define	PFIL_INET_NAME		"inet"
268 
269 VNET_DECLARE(struct pfil_head *, inet_local_pfil_head);
270 #define	V_inet_local_pfil_head	VNET(inet_local_pfil_head)
271 #define	PFIL_INET_LOCAL_NAME	"inet-local"
272 
273 void	in_delayed_cksum(struct mbuf *m);
274 
275 /* Hooks for ipfw, dummynet, divert etc. Most are declared in raw_ip.c */
276 /*
277  * Reference to an ipfw or packet filter rule that can be carried
278  * outside critical sections.
279  * A rule is identified by rulenum:rule_id which is ordered.
280  * In version chain_id the rule can be found in slot 'slot', so
281  * we don't need a lookup if chain_id == chain->id.
282  *
283  * On exit from the firewall this structure refers to the rule after
284  * the matching one (slot points to the new rule; rulenum:rule_id-1
285  * is the matching rule), and additional info (e.g. info often contains
286  * the insn argument or tablearg in the low 16 bits, in host format).
287  * On entry, the structure is valid if slot>0, and refers to the starting
288  * rules. 'info' contains the reason for reinject, e.g. divert port,
289  * divert direction, and so on.
290  *
291  * Packet Mark is an analogue to ipfw tags with O(1) lookup from mbuf while
292  * regular tags require a single-linked list traversal. Mark is a 32-bit
293  * number that can be looked up in a table [with 'number' table-type], matched
294  * or compared with a number with optional mask applied before comparison.
295  * Having generic nature, Mark can be used in a variety of needs.
296  * For example, it could be used as a security group: mark will hold a
297  * security group id and represent a group of packet flows that shares same
298  * access control policy.
299  * O_MASK opcode can match mark value bitwise so one can build a hierarchical
300  * model designating different meanings for a bit range(s).
301  */
302 struct ipfw_rule_ref {
303 /* struct m_tag spans 24 bytes above this point, see mbuf_tags(9) */
304 	/* spare space just to be save in case struct m_tag grows */
305 /* -- 32 bytes -- */
306 	uint32_t	slot;		/* slot for matching rule	*/
307 	uint32_t	rulenum;	/* matching rule number		*/
308 	uint32_t	rule_id;	/* matching rule id		*/
309 	uint32_t	chain_id;	/* ruleset id			*/
310 	uint32_t	info;		/* see below			*/
311 	uint32_t	pkt_mark;	/* packet mark			*/
312 	uint32_t	spare[2];
313 /* -- 64 bytes -- */
314 };
315 
316 enum {
317 	IPFW_INFO_MASK	= 0x0000ffff,
318 	IPFW_INFO_OUT	= 0x00000000,	/* outgoing, just for convenience */
319 	IPFW_INFO_IN	= 0x80000000,	/* incoming, overloads dir */
320 	IPFW_ONEPASS	= 0x40000000,	/* One-pass, do not reinject */
321 	IPFW_IS_MASK	= 0x30000000,	/* which source ? */
322 	IPFW_IS_DIVERT	= 0x20000000,
323 	IPFW_IS_DUMMYNET =0x10000000,
324 	IPFW_IS_PIPE	= 0x08000000,	/* pipe=1, queue = 0 */
325 };
326 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
327 #define MTAG_IPFW_RULE	1262273568	/* rule reference */
328 #define	MTAG_IPFW_CALL	1308397630	/* call stack */
329 
330 struct ip_fw_args;
331 typedef int	(*ip_fw_ctl_ptr_t)(struct sockopt *);
332 VNET_DECLARE(ip_fw_ctl_ptr_t, ip_fw_ctl_ptr);
333 #define	V_ip_fw_ctl_ptr		VNET(ip_fw_ctl_ptr)
334 
335 /* Divert hooks. */
336 extern void	(*ip_divert_ptr)(struct mbuf *m, bool incoming);
337 /* ng_ipfw hooks -- XXX make it the same as divert and dummynet */
338 extern int	(*ng_ipfw_input_p)(struct mbuf **, struct ip_fw_args *, bool);
339 extern int	(*ip_dn_ctl_ptr)(struct sockopt *);
340 extern int	(*ip_dn_io_ptr)(struct mbuf **, struct ip_fw_args *);
341 
342 /* pf specific mtag for divert(4) support */
__enum_uint8_decl(pf_mtag_dir)343 __enum_uint8_decl(pf_mtag_dir) {
344 	PF_DIVERT_MTAG_DIR_IN = 1,
345 	PF_DIVERT_MTAG_DIR_OUT = 2
346 };
347 struct pf_divert_mtag {
348 	__enum_uint8(pf_mtag_dir) idir;		/* initial pkt direction */
349 	union {
350 		__enum_uint8(pf_mtag_dir) ndir;	/* new dir after re-enter */
351 		uint16_t port;			/* initial divert(4) port */
352 	};
353 };
354 #define MTAG_PF_DIVERT	1262273569
355 
356 #endif /* _KERNEL */
357 
358 #endif /* !_NETINET_IP_VAR_H_ */
359