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unneback |
/*
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2 |
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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33 |
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* $Id: ip_divert.c,v 1.2 2001-09-27 12:01:55 chris Exp $
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34 |
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*/
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35 |
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36 |
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#include <sys/param.h>
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37 |
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#include <sys/queue.h>
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38 |
|
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#include <sys/malloc.h>
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39 |
|
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#include <sys/mbuf.h>
|
40 |
|
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#include <sys/socket.h>
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41 |
|
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#include <sys/protosw.h>
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42 |
|
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#include <sys/socketvar.h>
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43 |
|
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#include <sys/errno.h>
|
44 |
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#include <sys/systm.h>
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45 |
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|
46 |
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#include <net/if.h>
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47 |
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#include <net/route.h>
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48 |
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|
49 |
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#include <netinet/in.h>
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50 |
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#include <netinet/in_systm.h>
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51 |
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#include <netinet/ip.h>
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52 |
|
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#include <netinet/in_pcb.h>
|
53 |
|
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#include <netinet/in_var.h>
|
54 |
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#include <netinet/ip_var.h>
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55 |
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|
56 |
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/*
|
57 |
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* Divert sockets
|
58 |
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|
*/
|
59 |
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|
|
60 |
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/*
|
61 |
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* Allocate enough space to hold a full IP packet
|
62 |
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*/
|
63 |
|
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#define DIVSNDQ (65536 + 100)
|
64 |
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#define DIVRCVQ (65536 + 100)
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65 |
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|
66 |
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/* Global variables */
|
67 |
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|
68 |
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/*
|
69 |
|
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* ip_input() and ip_output() set this secret value before calling us to
|
70 |
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* let us know which divert port to divert a packet to; this is done so
|
71 |
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* we can use the existing prototype for struct protosw's pr_input().
|
72 |
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* This is stored in host order.
|
73 |
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|
*/
|
74 |
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u_short ip_divert_port;
|
75 |
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|
76 |
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/*
|
77 |
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* We set this value to a non-zero port number when we want the call to
|
78 |
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* ip_fw_chk() in ip_input() or ip_output() to ignore ``divert <port>''
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79 |
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* chain entries. This is stored in host order.
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80 |
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|
*/
|
81 |
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u_short ip_divert_ignore;
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82 |
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|
83 |
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/* Internal variables */
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84 |
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|
85 |
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static struct inpcbhead divcb;
|
86 |
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static struct inpcbinfo divcbinfo;
|
87 |
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|
88 |
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static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
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89 |
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static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
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90 |
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|
91 |
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/* Optimization: have this preinitialized */
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92 |
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static struct sockaddr_in divsrc = { sizeof(divsrc), AF_INET };
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93 |
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|
94 |
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/* Internal functions */
|
95 |
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|
96 |
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static int div_output(struct socket *so,
|
97 |
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|
struct mbuf *m, struct mbuf *addr, struct mbuf *control);
|
98 |
|
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|
99 |
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/*
|
100 |
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* Initialize divert connection block queue.
|
101 |
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|
*/
|
102 |
|
|
void
|
103 |
|
|
div_init(void)
|
104 |
|
|
{
|
105 |
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LIST_INIT(&divcb);
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106 |
|
|
divcbinfo.listhead = &divcb;
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107 |
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/*
|
108 |
|
|
* XXX We don't use the hash list for divert IP, but it's easier
|
109 |
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|
* to allocate a one entry hash list than it is to check all
|
110 |
|
|
* over the place for hashbase == NULL.
|
111 |
|
|
*/
|
112 |
|
|
divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
|
113 |
|
|
}
|
114 |
|
|
|
115 |
|
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/*
|
116 |
|
|
* Setup generic address and protocol structures
|
117 |
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|
* for div_input routine, then pass them along with
|
118 |
|
|
* mbuf chain. ip->ip_len is assumed to have had
|
119 |
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* the header length (hlen) subtracted out already.
|
120 |
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* We tell whether the packet was incoming or outgoing
|
121 |
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* by seeing if hlen == 0, which is a hack.
|
122 |
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|
*/
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123 |
|
|
void
|
124 |
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|
div_input(struct mbuf *m, int hlen)
|
125 |
|
|
{
|
126 |
|
|
struct ip *ip;
|
127 |
|
|
struct inpcb *inp;
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128 |
|
|
struct socket *sa;
|
129 |
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|
|
130 |
|
|
/* Sanity check */
|
131 |
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if (ip_divert_port == 0)
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132 |
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panic("div_input: port is 0");
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133 |
|
|
|
134 |
|
|
/* Assure header */
|
135 |
|
|
if (m->m_len < sizeof(struct ip) &&
|
136 |
|
|
(m = m_pullup(m, sizeof(struct ip))) == 0) {
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137 |
|
|
return;
|
138 |
|
|
}
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139 |
|
|
ip = mtod(m, struct ip *);
|
140 |
|
|
|
141 |
|
|
/* Record divert port */
|
142 |
|
|
divsrc.sin_port = htons(ip_divert_port);
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143 |
|
|
|
144 |
|
|
/* Restore packet header fields */
|
145 |
|
|
ip->ip_len += hlen;
|
146 |
|
|
HTONS(ip->ip_len);
|
147 |
|
|
HTONS(ip->ip_off);
|
148 |
|
|
|
149 |
|
|
/* Record receive interface address, if any */
|
150 |
|
|
divsrc.sin_addr.s_addr = 0;
|
151 |
|
|
if (hlen) {
|
152 |
|
|
struct ifaddr *ifa;
|
153 |
|
|
|
154 |
|
|
#ifdef DIAGNOSTIC
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155 |
|
|
/* Sanity check */
|
156 |
|
|
if (!(m->m_flags & M_PKTHDR))
|
157 |
|
|
panic("div_input: no pkt hdr");
|
158 |
|
|
#endif
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159 |
|
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|
160 |
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/* More fields affected by ip_input() */
|
161 |
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HTONS(ip->ip_id);
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162 |
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|
163 |
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/* Find IP address for recieve interface */
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164 |
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for (ifa = m->m_pkthdr.rcvif->if_addrlist;
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165 |
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ifa != NULL; ifa = ifa->ifa_next) {
|
166 |
|
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if (ifa->ifa_addr == NULL)
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167 |
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|
continue;
|
168 |
|
|
if (ifa->ifa_addr->sa_family != AF_INET)
|
169 |
|
|
continue;
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170 |
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divsrc.sin_addr =
|
171 |
|
|
((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
|
172 |
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break;
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173 |
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|
}
|
174 |
|
|
}
|
175 |
|
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|
176 |
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/* Put packet on socket queue, if any */
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177 |
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sa = NULL;
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178 |
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for (inp = divcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
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179 |
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if (inp->inp_lport == htons(ip_divert_port))
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180 |
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sa = inp->inp_socket;
|
181 |
|
|
}
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182 |
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if (sa) {
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183 |
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|
if (sbappendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc,
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184 |
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m, (struct mbuf *)0) == 0)
|
185 |
|
|
m_freem(m);
|
186 |
|
|
else
|
187 |
|
|
sorwakeup(sa);
|
188 |
|
|
} else {
|
189 |
|
|
m_freem(m);
|
190 |
|
|
ipstat.ips_noproto++;
|
191 |
|
|
ipstat.ips_delivered--;
|
192 |
|
|
}
|
193 |
|
|
}
|
194 |
|
|
|
195 |
|
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/*
|
196 |
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* Deliver packet back into the IP processing machinery.
|
197 |
|
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*
|
198 |
|
|
* If no address specified, or address is 0.0.0.0, send to ip_output();
|
199 |
|
|
* otherwise, send to ip_input() and mark as having been received on
|
200 |
|
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* the interface with that address.
|
201 |
|
|
*
|
202 |
|
|
* If no address specified, or dest port is 0, allow packet to divert
|
203 |
|
|
* back to this socket; otherwise, don't.
|
204 |
|
|
*/
|
205 |
|
|
static int
|
206 |
|
|
div_output(so, m, addr, control)
|
207 |
|
|
struct socket *so;
|
208 |
|
|
register struct mbuf *m;
|
209 |
|
|
struct mbuf *addr, *control;
|
210 |
|
|
{
|
211 |
|
|
register struct inpcb *const inp = sotoinpcb(so);
|
212 |
|
|
register struct ip *const ip = mtod(m, struct ip *);
|
213 |
|
|
struct sockaddr_in *sin = NULL;
|
214 |
|
|
int error = 0;
|
215 |
|
|
|
216 |
|
|
if (control)
|
217 |
|
|
m_freem(control); /* XXX */
|
218 |
|
|
if (addr)
|
219 |
|
|
sin = mtod(addr, struct sockaddr_in *);
|
220 |
|
|
|
221 |
|
|
/* Loopback avoidance option */
|
222 |
|
|
ip_divert_ignore = ntohs(inp->inp_lport);
|
223 |
|
|
|
224 |
|
|
/* Reinject packet into the system as incoming or outgoing */
|
225 |
|
|
if (!sin || sin->sin_addr.s_addr == 0) {
|
226 |
|
|
/* Don't allow both user specified and setsockopt options,
|
227 |
|
|
and don't allow packet length sizes that will crash */
|
228 |
|
|
if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
|
229 |
|
|
((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
|
230 |
|
|
error = EINVAL;
|
231 |
|
|
goto cantsend;
|
232 |
|
|
}
|
233 |
|
|
|
234 |
|
|
/* Convert fields to host order for ip_output() */
|
235 |
|
|
NTOHS(ip->ip_len);
|
236 |
|
|
NTOHS(ip->ip_off);
|
237 |
|
|
|
238 |
|
|
/* Send packet to output processing */
|
239 |
|
|
ipstat.ips_rawout++; /* XXX */
|
240 |
|
|
error = ip_output(m, inp->inp_options, &inp->inp_route,
|
241 |
|
|
(so->so_options & SO_DONTROUTE) |
|
242 |
|
|
IP_ALLOWBROADCAST | IP_RAWOUTPUT, inp->inp_moptions);
|
243 |
|
|
} else {
|
244 |
|
|
struct ifaddr *ifa;
|
245 |
|
|
|
246 |
|
|
/* Find receive interface with the given IP address */
|
247 |
|
|
sin->sin_port = 0;
|
248 |
|
|
if ((ifa = ifa_ifwithaddr((struct sockaddr *) sin)) == 0) {
|
249 |
|
|
error = EADDRNOTAVAIL;
|
250 |
|
|
goto cantsend;
|
251 |
|
|
}
|
252 |
|
|
m->m_pkthdr.rcvif = ifa->ifa_ifp;
|
253 |
|
|
|
254 |
|
|
/* Send packet to input processing */
|
255 |
|
|
ip_input(m);
|
256 |
|
|
}
|
257 |
|
|
|
258 |
|
|
/* Reset for next time (and other packets) */
|
259 |
|
|
ip_divert_ignore = 0;
|
260 |
|
|
return error;
|
261 |
|
|
|
262 |
|
|
cantsend:
|
263 |
|
|
ip_divert_ignore = 0;
|
264 |
|
|
m_freem(m);
|
265 |
|
|
return error;
|
266 |
|
|
}
|
267 |
|
|
|
268 |
|
|
/*ARGSUSED*/
|
269 |
|
|
int
|
270 |
|
|
div_usrreq(so, req, m, nam, control)
|
271 |
|
|
register struct socket *so;
|
272 |
|
|
int req;
|
273 |
|
|
struct mbuf *m, *nam, *control;
|
274 |
|
|
{
|
275 |
|
|
register int error = 0;
|
276 |
|
|
register struct inpcb *inp = sotoinpcb(so);
|
277 |
|
|
int s;
|
278 |
|
|
|
279 |
|
|
if (inp == NULL && req != PRU_ATTACH) {
|
280 |
|
|
error = EINVAL;
|
281 |
|
|
goto release;
|
282 |
|
|
}
|
283 |
|
|
switch (req) {
|
284 |
|
|
|
285 |
|
|
case PRU_ATTACH:
|
286 |
|
|
if (inp)
|
287 |
|
|
panic("div_attach");
|
288 |
|
|
if ((so->so_state & SS_PRIV) == 0) {
|
289 |
|
|
error = EACCES;
|
290 |
|
|
break;
|
291 |
|
|
}
|
292 |
|
|
s = splnet();
|
293 |
|
|
error = in_pcballoc(so, &divcbinfo);
|
294 |
|
|
splx(s);
|
295 |
|
|
if (error)
|
296 |
|
|
break;
|
297 |
|
|
error = soreserve(so, div_sendspace, div_recvspace);
|
298 |
|
|
if (error)
|
299 |
|
|
break;
|
300 |
|
|
inp = (struct inpcb *)so->so_pcb;
|
301 |
|
|
inp->inp_ip_p = (int)nam; /* XXX */
|
302 |
|
|
inp->inp_flags |= INP_HDRINCL;
|
303 |
|
|
/* The socket is always "connected" because
|
304 |
|
|
we always know "where" to send the packet */
|
305 |
|
|
so->so_state |= SS_ISCONNECTED;
|
306 |
|
|
break;
|
307 |
|
|
|
308 |
|
|
case PRU_DISCONNECT:
|
309 |
|
|
if ((so->so_state & SS_ISCONNECTED) == 0) {
|
310 |
|
|
error = ENOTCONN;
|
311 |
|
|
break;
|
312 |
|
|
}
|
313 |
|
|
/* FALLTHROUGH */
|
314 |
|
|
case PRU_ABORT:
|
315 |
|
|
soisdisconnected(so);
|
316 |
|
|
/* FALLTHROUGH */
|
317 |
|
|
case PRU_DETACH:
|
318 |
|
|
if (inp == 0)
|
319 |
|
|
panic("div_detach");
|
320 |
|
|
in_pcbdetach(inp);
|
321 |
|
|
break;
|
322 |
|
|
|
323 |
|
|
case PRU_BIND:
|
324 |
|
|
s = splnet();
|
325 |
|
|
error = in_pcbbind(inp, nam);
|
326 |
|
|
splx(s);
|
327 |
|
|
break;
|
328 |
|
|
|
329 |
|
|
/*
|
330 |
|
|
* Mark the connection as being incapable of further input.
|
331 |
|
|
*/
|
332 |
|
|
case PRU_SHUTDOWN:
|
333 |
|
|
socantsendmore(so);
|
334 |
|
|
break;
|
335 |
|
|
|
336 |
|
|
case PRU_SEND:
|
337 |
|
|
/* Packet must have a header (but that's about it) */
|
338 |
|
|
if (m->m_len < sizeof (struct ip) ||
|
339 |
|
|
(m = m_pullup(m, sizeof (struct ip))) == 0) {
|
340 |
|
|
ipstat.ips_toosmall++;
|
341 |
|
|
error = EINVAL;
|
342 |
|
|
break;
|
343 |
|
|
}
|
344 |
|
|
|
345 |
|
|
/* Send packet */
|
346 |
|
|
error = div_output(so, m, nam, control);
|
347 |
|
|
m = NULL;
|
348 |
|
|
break;
|
349 |
|
|
|
350 |
|
|
case PRU_SOCKADDR:
|
351 |
|
|
in_setsockaddr(inp, nam);
|
352 |
|
|
break;
|
353 |
|
|
|
354 |
|
|
case PRU_SENSE:
|
355 |
|
|
/*
|
356 |
|
|
* stat: don't bother with a blocksize.
|
357 |
|
|
*/
|
358 |
|
|
return (0);
|
359 |
|
|
|
360 |
|
|
/*
|
361 |
|
|
* Not supported.
|
362 |
|
|
*/
|
363 |
|
|
case PRU_CONNECT:
|
364 |
|
|
case PRU_CONNECT2:
|
365 |
|
|
case PRU_CONTROL:
|
366 |
|
|
case PRU_RCVOOB:
|
367 |
|
|
case PRU_RCVD:
|
368 |
|
|
case PRU_LISTEN:
|
369 |
|
|
case PRU_ACCEPT:
|
370 |
|
|
case PRU_SENDOOB:
|
371 |
|
|
case PRU_PEERADDR:
|
372 |
|
|
error = EOPNOTSUPP;
|
373 |
|
|
break;
|
374 |
|
|
|
375 |
|
|
default:
|
376 |
|
|
panic("div_usrreq");
|
377 |
|
|
}
|
378 |
|
|
release:
|
379 |
|
|
if (m)
|
380 |
|
|
m_freem(m);
|
381 |
|
|
return (error);
|
382 |
|
|
}
|