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1 /*
2  * Copyright (c) 2000 Wichert Akkerman <wakkerma@debian.org>
3  * Copyright (c) 2011 Denys Vlasenko <dvlasenk@redhat.com>
4  * Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
5  * Copyright (c) 2014-2017 The strace developers.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "defs.h"
32 
33 /* these constants are the same as in <linux/capability.h> */
34 enum {
35 #include "caps0.h"
36 };
37 
38 #include "xlat/cap_mask0.h"
39 
40 /* these constants are CAP_TO_INDEX'ed constants from <linux/capability.h> */
41 enum {
42 #include "caps1.h"
43 };
44 
45 #include "xlat/cap_mask1.h"
46 
47 /* these constants are the same as in <linux/capability.h> */
48 enum {
49 	_LINUX_CAPABILITY_VERSION_1 = 0x19980330,
50 	_LINUX_CAPABILITY_VERSION_2 = 0x20071026,
51 	_LINUX_CAPABILITY_VERSION_3 = 0x20080522
52 };
53 
54 #include "xlat/cap_version.h"
55 
56 struct user_cap_header_struct {
57 	uint32_t version;
58 	int pid;
59 };
60 
61 struct user_cap_data_struct {
62 	uint32_t effective;
63 	uint32_t permitted;
64 	uint32_t inheritable;
65 };
66 
67 static const struct user_cap_header_struct *
get_cap_header(struct tcb * const tcp,const kernel_ulong_t addr)68 get_cap_header(struct tcb *const tcp, const kernel_ulong_t addr)
69 {
70 	static struct user_cap_header_struct header;
71 
72 	if (!addr || !verbose(tcp))
73 		return NULL;
74 
75 	if (umove(tcp, addr, &header) < 0)
76 		return NULL;
77 
78 	return &header;
79 }
80 
81 static void
print_cap_header(struct tcb * const tcp,const kernel_ulong_t addr,const struct user_cap_header_struct * const h)82 print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
83 		 const struct user_cap_header_struct *const h)
84 {
85 	if (!addr || !h) {
86 		printaddr(addr);
87 		return;
88 	}
89 
90 	tprints("{version=");
91 	printxval(cap_version, h->version,
92 		  "_LINUX_CAPABILITY_VERSION_???");
93 	tprintf(", pid=%d}", h->pid);
94 }
95 
96 static void
print_cap_bits(const uint32_t lo,const uint32_t hi)97 print_cap_bits(const uint32_t lo, const uint32_t hi)
98 {
99 	if (lo || !hi)
100 		printflags(cap_mask0, lo, "CAP_???");
101 
102 	if (hi) {
103 		if (lo)
104 			tprints("|");
105 		printflags(cap_mask1, hi, "CAP_???");
106 	}
107 }
108 
109 static void
print_cap_data(struct tcb * const tcp,const kernel_ulong_t addr,const struct user_cap_header_struct * const h)110 print_cap_data(struct tcb *const tcp, const kernel_ulong_t addr,
111 	       const struct user_cap_header_struct *const h)
112 {
113 	struct user_cap_data_struct data[2];
114 	unsigned int len;
115 
116 	if (!addr || !h) {
117 		printaddr(addr);
118 		return;
119 	}
120 
121 	if (_LINUX_CAPABILITY_VERSION_2 == h->version ||
122 	    _LINUX_CAPABILITY_VERSION_3 == h->version)
123 		len = 2;
124 	else
125 		len = 1;
126 
127 	if (umoven_or_printaddr(tcp, addr, len * sizeof(data[0]), data))
128 		return;
129 
130 	tprints("{effective=");
131 	print_cap_bits(data[0].effective, len > 1 ? data[1].effective : 0);
132 	tprints(", permitted=");
133 	print_cap_bits(data[0].permitted, len > 1 ? data[1].permitted : 0);
134 	tprints(", inheritable=");
135 	print_cap_bits(data[0].inheritable, len > 1 ? data[1].inheritable : 0);
136 	tprints("}");
137 }
138 
SYS_FUNC(capget)139 SYS_FUNC(capget)
140 {
141 	const struct user_cap_header_struct *h;
142 
143 	if (entering(tcp)) {
144 		h = get_cap_header(tcp, tcp->u_arg[0]);
145 		print_cap_header(tcp, tcp->u_arg[0], h);
146 		tprints(", ");
147 	} else {
148 		h = syserror(tcp) ? NULL : get_cap_header(tcp, tcp->u_arg[0]);
149 		print_cap_data(tcp, tcp->u_arg[1], h);
150 	}
151 	return 0;
152 }
153 
SYS_FUNC(capset)154 SYS_FUNC(capset)
155 {
156 	const struct user_cap_header_struct *const h =
157 		get_cap_header(tcp, tcp->u_arg[0]);
158 	print_cap_header(tcp, tcp->u_arg[0], h);
159 	tprints(", ");
160 	print_cap_data(tcp, tcp->u_arg[1], h);
161 
162 	return RVAL_DECODED;
163 }
164