summaryrefslogtreecommitdiff
path: root/lib/util/substitute.c
blob: 500d12777f9a5c908de5d6727839a0999d7f11cf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* 
   Unix SMB/CIFS implementation.
   Samba utility functions
   
   Copyright (C) Andrew Tridgell 1992-2001
   Copyright (C) Simo Sorce      2001-2002
   Copyright (C) Martin Pool     2003
   Copyright (C) James Peach	 2005
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"

/**
 * @file
 * @brief Substitute utilities.
 **/

/**
 Substitute a string for a pattern in another string. Make sure there is
 enough room!

 This routine looks for pattern in s and replaces it with
 insert. It may do multiple replacements or just one.

 Any of " ; ' $ or ` in the insert string are replaced with _
 if len==0 then the string cannot be extended. This is different from the old
 use of len==0 which was for no length checks to be done.
**/

static void string_sub2(char *s,const char *pattern, const char *insert, size_t len,
			bool remove_unsafe_characters, bool replace_once,
			bool allow_trailing_dollar)
{
	char *p;
	ssize_t ls, lp, li, i;

	if (!insert || !pattern || !*pattern || !s)
		return;

	ls = (ssize_t)strlen(s);
	lp = (ssize_t)strlen(pattern);
	li = (ssize_t)strlen(insert);

	if (len == 0)
		len = ls + 1; /* len is number of *bytes* */

	while (lp <= ls && (p = strstr_m(s,pattern))) {
		if (ls + (li-lp) >= len) {
			DEBUG(0,("ERROR: string overflow by "
				"%d in string_sub(%.50s, %d)\n",
				 (int)(ls + (li-lp) - len),
				 pattern, (int)len));
			break;
		}
		if (li != lp) {
			memmove(p+li,p+lp,strlen(p+lp)+1);
		}
		for (i=0;i<li;i++) {
			switch (insert[i]) {
			case '$':
				/* allow a trailing $
				 * (as in machine accounts) */
				if (allow_trailing_dollar && (i == li - 1 )) {
					p[i] = insert[i];
					break;
				}
			case '`':
			case '"':
			case '\'':
			case ';':
			case '%':
			case '\r':
			case '\n':
				if ( remove_unsafe_characters ) {
					p[i] = '_';
					/* yes this break should be here
					 * since we want to fall throw if
					 * not replacing unsafe chars */
					break;
				}
			default:
				p[i] = insert[i];
			}
		}
		s = p + li;
		ls += (li-lp);

		if (replace_once)
			break;
	}
}

void string_sub_once(char *s, const char *pattern,
		const char *insert, size_t len)
{
	string_sub2( s, pattern, insert, len, true, true, false );
}

void string_sub(char *s,const char *pattern, const char *insert, size_t len)
{
	string_sub2( s, pattern, insert, len, true, false, false );
}

/**
 * Talloc'ed version of string_sub
 */
_PUBLIC_ char *string_sub_talloc(TALLOC_CTX *mem_ctx, const char *s, 
				const char *pattern, const char *insert)
{
	const char *p;
	char *ret;
	size_t len, alloc_len;

	if (insert == NULL || pattern == NULL || !*pattern || s == NULL)
		return NULL;

	/* determine length needed */
	len = strlen(s);
	
	for (p = strstr(s, pattern); p != NULL; 
	     p = strstr(p+strlen(pattern), pattern)) {
		len += strlen(insert) - strlen(pattern);
	}

	alloc_len = MAX(len, strlen(s))+1;
	ret = talloc_array(mem_ctx, char, alloc_len);
	if (ret == NULL)
		return NULL;
	strncpy(ret, s, alloc_len);
	string_sub(ret, pattern, insert, alloc_len);

	ret = talloc_realloc(mem_ctx, ret, char, len+1);
	if (ret == NULL)
		return NULL;

	SMB_ASSERT(ret[len] == '\0');

	talloc_set_name_const(ret, ret);

	return ret;
}

/**
 Similar to string_sub() but allows for any character to be substituted. 
 Use with caution!
 if len==0 then the string cannot be extended. This is different from the old
 use of len==0 which was for no length checks to be done.
**/

_PUBLIC_ void all_string_sub(char *s,const char *pattern,const char *insert, size_t len)
{
	char *p;
	ssize_t ls,lp,li;

	if (!insert || !pattern || !s)
		return;

	ls = (ssize_t)strlen(s);
	lp = (ssize_t)strlen(pattern);
	li = (ssize_t)strlen(insert);

	if (!*pattern)
		return;

	if (len == 0)
		len = ls + 1; /* len is number of *bytes* */

	while (lp <= ls && (p = strstr_m(s,pattern))) {
		if (ls + (li-lp) >= len) {
			DEBUG(0,("ERROR: string overflow by "
				"%d in all_string_sub(%.50s, %d)\n",
				 (int)(ls + (li-lp) - len),
				 pattern, (int)len));
			break;
		}
		if (li != lp) {
			memmove(p+li,p+lp,strlen(p+lp)+1);
		}
		memcpy(p, insert, li);
		s = p + li;
		ls += (li-lp);
	}
}