1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * System call table mapper
4  *
5  * (C) 2016 Arnaldo Carvalho de Melo <acme@redhat.com>
6  */
7 
8 #include "syscalltbl.h"
9 #include <stdlib.h>
10 #include <linux/compiler.h>
11 #include <linux/zalloc.h>
12 
13 #ifdef HAVE_SYSCALL_TABLE_SUPPORT
14 #include <string.h>
15 #include "string2.h"
16 
17 #if defined(__x86_64__)
18 #include <asm/syscalls_64.c>
19 const int syscalltbl_native_max_id = SYSCALLTBL_x86_64_MAX_ID;
20 static const char **syscalltbl_native = syscalltbl_x86_64;
21 #elif defined(__s390x__)
22 #include <asm/syscalls_64.c>
23 const int syscalltbl_native_max_id = SYSCALLTBL_S390_64_MAX_ID;
24 static const char **syscalltbl_native = syscalltbl_s390_64;
25 #elif defined(__powerpc64__)
26 #include <asm/syscalls_64.c>
27 const int syscalltbl_native_max_id = SYSCALLTBL_POWERPC_64_MAX_ID;
28 static const char **syscalltbl_native = syscalltbl_powerpc_64;
29 #elif defined(__powerpc__)
30 #include <asm/syscalls_32.c>
31 const int syscalltbl_native_max_id = SYSCALLTBL_POWERPC_32_MAX_ID;
32 static const char **syscalltbl_native = syscalltbl_powerpc_32;
33 #elif defined(__aarch64__)
34 #include <asm/syscalls.c>
35 const int syscalltbl_native_max_id = SYSCALLTBL_ARM64_MAX_ID;
36 static const char **syscalltbl_native = syscalltbl_arm64;
37 #elif defined(__mips__)
38 #include <asm/syscalls_n64.c>
39 const int syscalltbl_native_max_id = SYSCALLTBL_MIPS_N64_MAX_ID;
40 static const char **syscalltbl_native = syscalltbl_mips_n64;
41 #endif
42 
43 struct syscall {
44 	int id;
45 	const char *name;
46 };
47 
syscallcmpname(const void * vkey,const void * ventry)48 static int syscallcmpname(const void *vkey, const void *ventry)
49 {
50 	const char *key = vkey;
51 	const struct syscall *entry = ventry;
52 
53 	return strcmp(key, entry->name);
54 }
55 
syscallcmp(const void * va,const void * vb)56 static int syscallcmp(const void *va, const void *vb)
57 {
58 	const struct syscall *a = va, *b = vb;
59 
60 	return strcmp(a->name, b->name);
61 }
62 
syscalltbl__init_native(struct syscalltbl * tbl)63 static int syscalltbl__init_native(struct syscalltbl *tbl)
64 {
65 	int nr_entries = 0, i, j;
66 	struct syscall *entries;
67 
68 	for (i = 0; i <= syscalltbl_native_max_id; ++i)
69 		if (syscalltbl_native[i])
70 			++nr_entries;
71 
72 	entries = tbl->syscalls.entries = malloc(sizeof(struct syscall) * nr_entries);
73 	if (tbl->syscalls.entries == NULL)
74 		return -1;
75 
76 	for (i = 0, j = 0; i <= syscalltbl_native_max_id; ++i) {
77 		if (syscalltbl_native[i]) {
78 			entries[j].name = syscalltbl_native[i];
79 			entries[j].id = i;
80 			++j;
81 		}
82 	}
83 
84 	qsort(tbl->syscalls.entries, nr_entries, sizeof(struct syscall), syscallcmp);
85 	tbl->syscalls.nr_entries = nr_entries;
86 	tbl->syscalls.max_id	 = syscalltbl_native_max_id;
87 	return 0;
88 }
89 
syscalltbl__new(void)90 struct syscalltbl *syscalltbl__new(void)
91 {
92 	struct syscalltbl *tbl = malloc(sizeof(*tbl));
93 	if (tbl) {
94 		if (syscalltbl__init_native(tbl)) {
95 			free(tbl);
96 			return NULL;
97 		}
98 	}
99 	return tbl;
100 }
101 
syscalltbl__delete(struct syscalltbl * tbl)102 void syscalltbl__delete(struct syscalltbl *tbl)
103 {
104 	zfree(&tbl->syscalls.entries);
105 	free(tbl);
106 }
107 
syscalltbl__name(const struct syscalltbl * tbl __maybe_unused,int id)108 const char *syscalltbl__name(const struct syscalltbl *tbl __maybe_unused, int id)
109 {
110 	return id <= syscalltbl_native_max_id ? syscalltbl_native[id]: NULL;
111 }
112 
syscalltbl__id(struct syscalltbl * tbl,const char * name)113 int syscalltbl__id(struct syscalltbl *tbl, const char *name)
114 {
115 	struct syscall *sc = bsearch(name, tbl->syscalls.entries,
116 				     tbl->syscalls.nr_entries, sizeof(*sc),
117 				     syscallcmpname);
118 
119 	return sc ? sc->id : -1;
120 }
121 
syscalltbl__strglobmatch_next(struct syscalltbl * tbl,const char * syscall_glob,int * idx)122 int syscalltbl__strglobmatch_next(struct syscalltbl *tbl, const char *syscall_glob, int *idx)
123 {
124 	int i;
125 	struct syscall *syscalls = tbl->syscalls.entries;
126 
127 	for (i = *idx + 1; i < tbl->syscalls.nr_entries; ++i) {
128 		if (strglobmatch(syscalls[i].name, syscall_glob)) {
129 			*idx = i;
130 			return syscalls[i].id;
131 		}
132 	}
133 
134 	return -1;
135 }
136 
syscalltbl__strglobmatch_first(struct syscalltbl * tbl,const char * syscall_glob,int * idx)137 int syscalltbl__strglobmatch_first(struct syscalltbl *tbl, const char *syscall_glob, int *idx)
138 {
139 	*idx = -1;
140 	return syscalltbl__strglobmatch_next(tbl, syscall_glob, idx);
141 }
142 
143 #else /* HAVE_SYSCALL_TABLE_SUPPORT */
144 
145 #include <libaudit.h>
146 
syscalltbl__new(void)147 struct syscalltbl *syscalltbl__new(void)
148 {
149 	struct syscalltbl *tbl = zalloc(sizeof(*tbl));
150 	if (tbl)
151 		tbl->audit_machine = audit_detect_machine();
152 	return tbl;
153 }
154 
syscalltbl__delete(struct syscalltbl * tbl)155 void syscalltbl__delete(struct syscalltbl *tbl)
156 {
157 	free(tbl);
158 }
159 
syscalltbl__name(const struct syscalltbl * tbl,int id)160 const char *syscalltbl__name(const struct syscalltbl *tbl, int id)
161 {
162 	return audit_syscall_to_name(id, tbl->audit_machine);
163 }
164 
syscalltbl__id(struct syscalltbl * tbl,const char * name)165 int syscalltbl__id(struct syscalltbl *tbl, const char *name)
166 {
167 	return audit_name_to_syscall(name, tbl->audit_machine);
168 }
169 
syscalltbl__strglobmatch_next(struct syscalltbl * tbl __maybe_unused,const char * syscall_glob __maybe_unused,int * idx __maybe_unused)170 int syscalltbl__strglobmatch_next(struct syscalltbl *tbl __maybe_unused,
171 				  const char *syscall_glob __maybe_unused, int *idx __maybe_unused)
172 {
173 	return -1;
174 }
175 
syscalltbl__strglobmatch_first(struct syscalltbl * tbl,const char * syscall_glob,int * idx)176 int syscalltbl__strglobmatch_first(struct syscalltbl *tbl, const char *syscall_glob, int *idx)
177 {
178 	return syscalltbl__strglobmatch_next(tbl, syscall_glob, idx);
179 }
180 #endif /* HAVE_SYSCALL_TABLE_SUPPORT */
181