1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * System call table mapper
4  *
5  * (C) 2016 Arnaldo Carvalho de Melo <[email protected]>
6  */
7 
8 #include "syscalltbl.h"
9 #include <stdlib.h>
10 #include <linux/compiler.h>
11 #include <linux/zalloc.h>
12 
13 #include <string.h>
14 #include "string2.h"
15 
16 #include <syscall_table.h>
17 const int syscalltbl_native_max_id = SYSCALLTBL_MAX_ID;
18 static const char *const *syscalltbl_native = syscalltbl;
19 
20 struct syscall {
21 	int id;
22 	const char *name;
23 };
24 
syscallcmpname(const void * vkey,const void * ventry)25 static int syscallcmpname(const void *vkey, const void *ventry)
26 {
27 	const char *key = vkey;
28 	const struct syscall *entry = ventry;
29 
30 	return strcmp(key, entry->name);
31 }
32 
syscallcmp(const void * va,const void * vb)33 static int syscallcmp(const void *va, const void *vb)
34 {
35 	const struct syscall *a = va, *b = vb;
36 
37 	return strcmp(a->name, b->name);
38 }
39 
syscalltbl__init_native(struct syscalltbl * tbl)40 static int syscalltbl__init_native(struct syscalltbl *tbl)
41 {
42 	int nr_entries = 0, i, j;
43 	struct syscall *entries;
44 
45 	for (i = 0; i <= syscalltbl_native_max_id; ++i)
46 		if (syscalltbl_native[i])
47 			++nr_entries;
48 
49 	entries = tbl->syscalls.entries = malloc(sizeof(struct syscall) * nr_entries);
50 	if (tbl->syscalls.entries == NULL)
51 		return -1;
52 
53 	for (i = 0, j = 0; i <= syscalltbl_native_max_id; ++i) {
54 		if (syscalltbl_native[i]) {
55 			entries[j].name = syscalltbl_native[i];
56 			entries[j].id = i;
57 			++j;
58 		}
59 	}
60 
61 	qsort(tbl->syscalls.entries, nr_entries, sizeof(struct syscall), syscallcmp);
62 	tbl->syscalls.nr_entries = nr_entries;
63 	tbl->syscalls.max_id	 = syscalltbl_native_max_id;
64 	return 0;
65 }
66 
syscalltbl__new(void)67 struct syscalltbl *syscalltbl__new(void)
68 {
69 	struct syscalltbl *tbl = malloc(sizeof(*tbl));
70 	if (tbl) {
71 		if (syscalltbl__init_native(tbl)) {
72 			free(tbl);
73 			return NULL;
74 		}
75 	}
76 	return tbl;
77 }
78 
syscalltbl__delete(struct syscalltbl * tbl)79 void syscalltbl__delete(struct syscalltbl *tbl)
80 {
81 	zfree(&tbl->syscalls.entries);
82 	free(tbl);
83 }
84 
syscalltbl__name(const struct syscalltbl * tbl __maybe_unused,int id)85 const char *syscalltbl__name(const struct syscalltbl *tbl __maybe_unused, int id)
86 {
87 	return id <= syscalltbl_native_max_id ? syscalltbl_native[id]: NULL;
88 }
89 
syscalltbl__id(struct syscalltbl * tbl,const char * name)90 int syscalltbl__id(struct syscalltbl *tbl, const char *name)
91 {
92 	struct syscall *sc = bsearch(name, tbl->syscalls.entries,
93 				     tbl->syscalls.nr_entries, sizeof(*sc),
94 				     syscallcmpname);
95 
96 	return sc ? sc->id : -1;
97 }
98 
syscalltbl__id_at_idx(struct syscalltbl * tbl,int idx)99 int syscalltbl__id_at_idx(struct syscalltbl *tbl, int idx)
100 {
101 	struct syscall *syscalls = tbl->syscalls.entries;
102 
103 	return idx < tbl->syscalls.nr_entries ? syscalls[idx].id : -1;
104 }
105 
syscalltbl__strglobmatch_next(struct syscalltbl * tbl,const char * syscall_glob,int * idx)106 int syscalltbl__strglobmatch_next(struct syscalltbl *tbl, const char *syscall_glob, int *idx)
107 {
108 	int i;
109 	struct syscall *syscalls = tbl->syscalls.entries;
110 
111 	for (i = *idx + 1; i < tbl->syscalls.nr_entries; ++i) {
112 		if (strglobmatch(syscalls[i].name, syscall_glob)) {
113 			*idx = i;
114 			return syscalls[i].id;
115 		}
116 	}
117 
118 	return -1;
119 }
120 
syscalltbl__strglobmatch_first(struct syscalltbl * tbl,const char * syscall_glob,int * idx)121 int syscalltbl__strglobmatch_first(struct syscalltbl *tbl, const char *syscall_glob, int *idx)
122 {
123 	*idx = -1;
124 	return syscalltbl__strglobmatch_next(tbl, syscall_glob, idx);
125 }
126