1 | /* Common code for file-based database parsers in nss_files module. |
2 | Copyright (C) 1996-2017 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <ctype.h> |
20 | #include <errno.h> |
21 | #include <string.h> |
22 | #include <stdlib.h> |
23 | #include <stdint.h> |
24 | |
25 | /* These symbols are defined by the including source file: |
26 | |
27 | ENTNAME -- database name of the structure and functions (hostent, pwent). |
28 | STRUCTURE -- struct name, define only if not ENTNAME (passwd, group). |
29 | DATABASE -- string of the database file's name ("hosts", "passwd"). |
30 | |
31 | ENTDATA -- if defined, `struct ENTDATA' is used by the parser to store |
32 | things pointed to by the resultant `struct STRUCTURE'. |
33 | |
34 | NEED_H_ERRNO - defined iff an arg `int *herrnop' is used. |
35 | |
36 | EXTRA_ARGS -- defined iff extra parameters must be passed to the parser |
37 | EXTRA_ARGS_DECL -- declaration for these extra parameters |
38 | EXTRA_ARGS_VALUE -- values to be passed for these parameters |
39 | |
40 | Also see files-XXX.c. */ |
41 | |
42 | #ifndef EXTRA_ARGS |
43 | # define |
44 | # define |
45 | # define |
46 | #endif |
47 | |
48 | #define CONCAT(a,b) CONCAT1(a,b) |
49 | #define CONCAT1(a,b) a##b |
50 | |
51 | #ifndef STRUCTURE |
52 | # define STRUCTURE ENTNAME |
53 | #endif |
54 | |
55 | |
56 | struct parser_data |
57 | { |
58 | #ifdef ENTDATA |
59 | struct ENTDATA entdata; |
60 | # define ENTDATA_DECL(data) struct ENTDATA *const entdata = &data->entdata; |
61 | #else |
62 | # define ENTDATA_DECL(data) |
63 | #endif |
64 | char linebuffer[0]; |
65 | }; |
66 | |
67 | #ifdef ENTDATA |
68 | /* The function can't be exported, because the entdata structure |
69 | is defined only in files-foo.c. */ |
70 | # define parser_stclass static |
71 | # define nss_files_parse_hidden_def(name) |
72 | #else |
73 | /* Export the line parser function so it can be used in nss_db. */ |
74 | # define parser_stclass /* Global */ |
75 | # define parse_line CONCAT(_nss_files_parse_,ENTNAME) |
76 | # if IS_IN (libc) |
77 | /* We are defining one of the functions that actually lives in libc |
78 | because it is used to implement fget*ent and suchlike. */ |
79 | # define nss_files_parse_hidden_def(name) libc_hidden_def (name) |
80 | # else |
81 | # define nss_files_parse_hidden_def(name) libnss_files_hidden_def (name) |
82 | # endif |
83 | #endif |
84 | |
85 | |
86 | #ifdef EXTERN_PARSER |
87 | |
88 | /* The parser is defined in a different module. */ |
89 | extern int parse_line (char *line, struct STRUCTURE *result, |
90 | struct parser_data *data, size_t datalen, int *errnop |
91 | EXTRA_ARGS_DECL); |
92 | |
93 | # define LINE_PARSER(EOLSET, BODY) /* Do nothing */ |
94 | |
95 | #else |
96 | |
97 | /* Define a line parsing function. */ |
98 | |
99 | # define LINE_PARSER(EOLSET, BODY) \ |
100 | parser_stclass int \ |
101 | parse_line (char *line, struct STRUCTURE *result, \ |
102 | struct parser_data *data, size_t datalen, int *errnop \ |
103 | EXTRA_ARGS_DECL) \ |
104 | { \ |
105 | ENTDATA_DECL (data) \ |
106 | BUFFER_PREPARE \ |
107 | char *p = strpbrk (line, EOLSET "\n"); \ |
108 | if (p != NULL) \ |
109 | *p = '\0'; \ |
110 | BODY; \ |
111 | TRAILING_LIST_PARSER; \ |
112 | return 1; \ |
113 | } \ |
114 | nss_files_parse_hidden_def (parse_line) |
115 | |
116 | |
117 | # define STRING_FIELD(variable, terminator_p, swallow) \ |
118 | { \ |
119 | variable = line; \ |
120 | while (*line != '\0' && !terminator_p (*line)) \ |
121 | ++line; \ |
122 | if (*line != '\0') \ |
123 | { \ |
124 | *line = '\0'; \ |
125 | do \ |
126 | ++line; \ |
127 | while (swallow && terminator_p (*line)); \ |
128 | } \ |
129 | } |
130 | |
131 | # define STRING_LIST(variable, terminator_c) \ |
132 | { \ |
133 | char **list = parse_list (&line, buf_start, buf_end, terminator_c, \ |
134 | errnop); \ |
135 | if (list) \ |
136 | variable = list; \ |
137 | else \ |
138 | return -1; /* -1 indicates we ran out of space. */ \ |
139 | \ |
140 | /* Determine the new end of the buffer. */ \ |
141 | while (*list != NULL) \ |
142 | ++list; \ |
143 | buf_start = (char *) (list + 1); \ |
144 | } |
145 | |
146 | /* Helper function. */ |
147 | static inline uint32_t |
148 | __attribute__ ((always_inline)) |
149 | strtou32 (const char *nptr, char **endptr, int base) |
150 | { |
151 | unsigned long int val = strtoul (nptr, endptr, base); |
152 | |
153 | /* Match the 32-bit behavior on 64-bit platforms. */ |
154 | if (sizeof (long int) > 4 && val > 0xffffffff) |
155 | val = 0xffffffff; |
156 | |
157 | return val; |
158 | } |
159 | |
160 | # define INT_FIELD(variable, terminator_p, swallow, base, convert) \ |
161 | { \ |
162 | char *endp; \ |
163 | variable = convert (strtou32 (line, &endp, base)); \ |
164 | if (endp == line) \ |
165 | return 0; \ |
166 | else if (terminator_p (*endp)) \ |
167 | do \ |
168 | ++endp; \ |
169 | while (swallow && terminator_p (*endp)); \ |
170 | else if (*endp != '\0') \ |
171 | return 0; \ |
172 | line = endp; \ |
173 | } |
174 | |
175 | # define INT_FIELD_MAYBE_NULL(variable, terminator_p, swallow, base, convert, default) \ |
176 | { \ |
177 | char *endp; \ |
178 | if (*line == '\0') \ |
179 | /* We expect some more input, so don't allow the string to end here. */ \ |
180 | return 0; \ |
181 | variable = convert (strtou32 (line, &endp, base)); \ |
182 | if (endp == line) \ |
183 | variable = default; \ |
184 | if (terminator_p (*endp)) \ |
185 | do \ |
186 | ++endp; \ |
187 | while (swallow && terminator_p (*endp)); \ |
188 | else if (*endp != '\0') \ |
189 | return 0; \ |
190 | line = endp; \ |
191 | } |
192 | |
193 | # define ISCOLON(c) ((c) == ':') |
194 | |
195 | |
196 | # ifndef TRAILING_LIST_MEMBER |
197 | # define BUFFER_PREPARE /* Nothing to do. */ |
198 | # define TRAILING_LIST_PARSER /* Nothing to do. */ |
199 | # else |
200 | |
201 | # define BUFFER_PREPARE \ |
202 | char *buf_start = NULL; \ |
203 | char *buf_end = (char *) data + datalen; \ |
204 | if (line >= data->linebuffer && line < buf_end) \ |
205 | /* Find the end of the line buffer, we will use the space in \ |
206 | DATA after it for storing the vector of pointers. */ \ |
207 | buf_start = strchr (line, '\0') + 1; \ |
208 | else \ |
209 | /* LINE does not point within DATA->linebuffer, so that space is \ |
210 | not being used for scratch space right now. We can use all of \ |
211 | it for the pointer vector storage. */ \ |
212 | buf_start = data->linebuffer; \ |
213 | |
214 | # define TRAILING_LIST_PARSER \ |
215 | { \ |
216 | if (buf_start == NULL) \ |
217 | { \ |
218 | if (line >= data->linebuffer && line < buf_end) \ |
219 | /* Find the end of the line buffer, we will use the space in \ |
220 | DATA after it for storing the vector of pointers. */ \ |
221 | buf_start = strchr (line, '\0') + 1; \ |
222 | else \ |
223 | /* LINE does not point within DATA->linebuffer, so that space is \ |
224 | not being used for scratch space right now. We can use all of \ |
225 | it for the pointer vector storage. */ \ |
226 | buf_start = data->linebuffer; \ |
227 | } \ |
228 | \ |
229 | char **list = parse_list (&line, buf_start, buf_end, '\0', errnop); \ |
230 | if (list) \ |
231 | result->TRAILING_LIST_MEMBER = list; \ |
232 | else \ |
233 | return -1; /* -1 indicates we ran out of space. */ \ |
234 | } |
235 | |
236 | static inline char ** |
237 | __attribute ((always_inline)) |
238 | parse_list (char **linep, char *eol, char *buf_end, int terminator_c, |
239 | int *errnop) |
240 | { |
241 | char *line = *linep; |
242 | char **list, **p; |
243 | |
244 | /* Adjust the pointer so it is aligned for storing pointers. */ |
245 | eol += __alignof__ (char *) - 1; |
246 | eol -= (eol - (char *) 0) % __alignof__ (char *); |
247 | /* We will start the storage here for the vector of pointers. */ |
248 | list = (char **) eol; |
249 | |
250 | p = list; |
251 | while (1) |
252 | { |
253 | if ((char *) (p + 2) > buf_end) |
254 | { |
255 | /* We cannot fit another pointer in the buffer. */ |
256 | *errnop = ERANGE; |
257 | return NULL; |
258 | } |
259 | |
260 | if (*line == '\0') |
261 | break; |
262 | if (*line == terminator_c) |
263 | { |
264 | ++line; |
265 | break; |
266 | } |
267 | |
268 | /* Skip leading white space. This might not be portable but useful. */ |
269 | while (isspace (*line)) |
270 | ++line; |
271 | |
272 | char *elt = line; |
273 | while (1) |
274 | { |
275 | if (*line == '\0' || *line == terminator_c |
276 | || TRAILING_LIST_SEPARATOR_P (*line)) |
277 | { |
278 | /* End of the next entry. */ |
279 | if (line > elt) |
280 | /* We really found some data. */ |
281 | *p++ = elt; |
282 | |
283 | /* Terminate string if necessary. */ |
284 | if (*line != '\0') |
285 | { |
286 | char endc = *line; |
287 | *line++ = '\0'; |
288 | if (endc == terminator_c) |
289 | goto out; |
290 | } |
291 | break; |
292 | } |
293 | ++line; |
294 | } |
295 | } |
296 | out: |
297 | *p = NULL; |
298 | *linep = line; |
299 | |
300 | return list; |
301 | } |
302 | |
303 | # endif /* TRAILING_LIST_MEMBER */ |
304 | #endif /* EXTERN_PARSER */ |
305 | |
306 | |
307 | #define LOOKUP_NAME(nameelt, aliaselt) \ |
308 | { \ |
309 | char **ap; \ |
310 | if (! strcmp (name, result->nameelt)) \ |
311 | break; \ |
312 | for (ap = result->aliaselt; *ap; ++ap) \ |
313 | if (! strcmp (name, *ap)) \ |
314 | break; \ |
315 | if (*ap) \ |
316 | break; \ |
317 | } |
318 | |
319 | #define LOOKUP_NAME_CASE(nameelt, aliaselt) \ |
320 | { \ |
321 | char **ap; \ |
322 | if (! __strcasecmp (name, result->nameelt)) \ |
323 | break; \ |
324 | for (ap = result->aliaselt; *ap; ++ap) \ |
325 | if (! __strcasecmp (name, *ap)) \ |
326 | break; \ |
327 | if (*ap) \ |
328 | break; \ |
329 | } |
330 | |
331 | |
332 | /* This is defined by db-*.c to include "../nss_db/db-XXX.c" instead. */ |
333 | #ifndef GENERIC |
334 | # define GENERIC "files-XXX.c" |
335 | #endif |
336 | |