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1 /*
2  * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
3  * Copyright (c) 2017 JingPiao Chen <chenjingpiao@gmail.com>
4  * Copyright (c) 2016-2018 The strace developers.
5  * 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. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "defs.h"
31 
32 #include "netlink_route.h"
33 #include "nlattr.h"
34 #include "print_fields.h"
35 
36 #include "netlink.h"
37 #include <linux/rtnetlink.h>
38 #ifdef HAVE_LINUX_FIB_RULES_H
39 # include <linux/fib_rules.h>
40 #endif
41 
42 #include "xlat/fib_rule_actions.h"
43 #include "xlat/fib_rule_flags.h"
44 #include "xlat/rtnl_rule_attrs.h"
45 
46 static bool
decode_rule_addr(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)47 decode_rule_addr(struct tcb *const tcp,
48 		 const kernel_ulong_t addr,
49 		 const unsigned int len,
50 		 const void *const opaque_data)
51 {
52 	const struct rtmsg *const rtmsg = opaque_data;
53 
54 	decode_inet_addr(tcp, addr, len, rtmsg->rtm_family, NULL);
55 
56 	return true;
57 }
58 
59 static bool
decode_fib_rule_uid_range(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)60 decode_fib_rule_uid_range(struct tcb *const tcp,
61 			  const kernel_ulong_t addr,
62 			  const unsigned int len,
63 			  const void *const opaque_data)
64 {
65 #ifdef HAVE_STRUCT_FIB_RULE_UID_RANGE
66 	struct fib_rule_uid_range range;
67 
68 	if (len < sizeof(range))
69 		return false;
70 	else if (!umove_or_printaddr(tcp, addr, &range)) {
71 		PRINT_FIELD_U("{", range, start);
72 		PRINT_FIELD_U(", ", range, end);
73 		tprints("}");
74 	}
75 
76 	return true;
77 #else
78 	return false;
79 #endif
80 }
81 
82 static bool
decode_rule_port_range(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)83 decode_rule_port_range(struct tcb *const tcp,
84 		       const kernel_ulong_t addr,
85 		       const unsigned int len,
86 		       const void *const opaque_data)
87 {
88 	struct /* fib_rule_port_range */ {
89 		uint16_t start;
90 		uint16_t end;
91 	} range;
92 
93 	if (len < sizeof(range))
94 		return false;
95 	else if (!umove_or_printaddr(tcp, addr, &range)) {
96 		PRINT_FIELD_U("{", range, start);
97 		PRINT_FIELD_U(", ", range, end);
98 		tprints("}");
99 	}
100 
101 	return true;
102 }
103 
104 static const nla_decoder_t fib_rule_hdr_nla_decoders[] = {
105 	[FRA_DST]			= decode_rule_addr,
106 	[FRA_SRC]			= decode_rule_addr,
107 	[FRA_IIFNAME]			= decode_nla_str,
108 	[FRA_GOTO]			= decode_nla_u32,
109 	[FRA_PRIORITY]			= decode_nla_u32,
110 	[FRA_FWMARK]			= decode_nla_u32,
111 	[FRA_FLOW]			= decode_nla_u32,
112 	[FRA_TUN_ID]			= decode_nla_be64,
113 	[FRA_SUPPRESS_IFGROUP]		= decode_nla_u32,
114 	[FRA_SUPPRESS_PREFIXLEN]	= decode_nla_u32,
115 	[FRA_TABLE]			= decode_nla_rt_class,
116 	[FRA_FWMASK]			= decode_nla_u32,
117 	[FRA_OIFNAME]			= decode_nla_str,
118 	[FRA_PAD]			= NULL,
119 	[FRA_L3MDEV]			= decode_nla_u8,
120 	[FRA_UID_RANGE]			= decode_fib_rule_uid_range,
121 	[FRA_PROTOCOL]			= decode_nla_rt_proto,
122 	[FRA_IP_PROTO]			= decode_nla_ip_proto,
123 	[FRA_SPORT_RANGE]		= decode_rule_port_range,
124 	[FRA_DPORT_RANGE]		= decode_rule_port_range,
125 };
126 
DECL_NETLINK_ROUTE_DECODER(decode_fib_rule_hdr)127 DECL_NETLINK_ROUTE_DECODER(decode_fib_rule_hdr)
128 {
129 	/*
130 	 * struct rtmsg and struct fib_rule_hdr are essentially
131 	 * the same structure, use struct rtmsg but treat it as
132 	 * struct fib_rule_hdr.
133 	 */
134 	struct rtmsg msg = { .rtm_family = family };
135 	size_t offset = sizeof(msg.rtm_family);
136 	bool decode_nla = false;
137 
138 	tprints("{family=");
139 	printxval(addrfams, msg.rtm_family, "AF_???");
140 
141 	tprints(", ");
142 	if (len >= sizeof(msg)) {
143 		if (!umoven_or_printaddr(tcp, addr + offset,
144 					 sizeof(msg) - offset,
145 					 (char *) &msg + offset)) {
146 			tprintf("dst_len=%u, src_len=%u",
147 				msg.rtm_dst_len, msg.rtm_src_len);
148 			tprints(", tos=");
149 			printflags(ip_type_of_services, msg.rtm_tos,
150 				   "IPTOS_TOS_???");
151 			tprints(", table=");
152 			printxval(routing_table_ids, msg.rtm_table, NULL);
153 			tprints(", action=");
154 			printxval(fib_rule_actions, msg.rtm_type, "FR_ACT_???");
155 			tprints(", flags=");
156 			printflags(fib_rule_flags, msg.rtm_flags,
157 				   "FIB_RULE_???");
158 			decode_nla = true;
159 		}
160 	} else
161 		tprints("...");
162 	tprints("}");
163 
164 	offset = NLMSG_ALIGN(sizeof(msg));
165 	if (decode_nla && len > offset) {
166 		tprints(", ");
167 		decode_nlattr(tcp, addr + offset, len - offset,
168 			      rtnl_rule_attrs, "FRA_???",
169 			      fib_rule_hdr_nla_decoders,
170 			      ARRAY_SIZE(fib_rule_hdr_nla_decoders), &msg);
171 	}
172 }
173