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1 | /* -*-c-*- |
2 | * |
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3 | * Handling of file attributes |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
10 | * This file is part of the `fw' port forwarder. |
11 | * |
12 | * `fw' is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License as published by |
14 | * the Free Software Foundation; either version 2 of the License, or |
15 | * (at your option) any later version. |
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16 | * |
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17 | * `fw' is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU General Public License |
23 | * along with `fw'; if not, write to the Free Software Foundation, |
24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
25 | */ |
26 | |
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27 | /*----- Header files ------------------------------------------------------*/ |
28 | |
29 | #include "config.h" |
30 | |
31 | #include <ctype.h> |
32 | #include <errno.h> |
33 | #include <stdio.h> |
34 | #include <stdlib.h> |
35 | #include <string.h> |
36 | |
37 | #include <sys/types.h> |
38 | #include <sys/stat.h> |
39 | #include <unistd.h> |
40 | |
41 | #include <pwd.h> |
42 | #include <grp.h> |
43 | |
44 | #include "conf.h" |
45 | #include "fattr.h" |
46 | #include "scan.h" |
47 | |
48 | /*----- Global variables --------------------------------------------------*/ |
49 | |
50 | fattr fattr_global; |
51 | |
52 | /*----- Main code ---------------------------------------------------------*/ |
53 | |
54 | /* --- @fattr_init@ --- * |
55 | * |
56 | * Arguments: @fattr *f@ = pointer to file attributes |
57 | * |
58 | * Returns: --- |
59 | * |
60 | * Use: Initializes a set of file attributes to default values. |
61 | */ |
62 | |
63 | void fattr_init(fattr *f) |
64 | { |
65 | unsigned um = umask(0); |
66 | umask(um); |
67 | f->mode = 0666 & ~um; |
68 | f->uid = -1; |
69 | f->gid = -1; |
70 | } |
71 | |
72 | /* --- @fattr_option@ --- * |
73 | * |
74 | * Arguments: @scanner *sc@ = pointer to scanner to read |
75 | * @fattr *f@ = pointer to file attributes to set |
76 | * |
77 | * Returns: Whether the option was claimed. |
78 | * |
79 | * Use: Reads file attributes from a scanner. |
80 | */ |
81 | |
82 | int fattr_option(scanner *sc, fattr *f) |
83 | { |
84 | CONF_BEGIN(sc, "fattr", "file attribute") |
85 | |
86 | /* --- Read a file mode specification --- */ |
87 | |
88 | if (strcmp(sc->d.buf, "mode") == 0) { |
89 | unsigned mode = 0; |
90 | |
91 | /* --- Gobble an optional `=' sign --- */ |
92 | |
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93 | conf_undelim(sc, 0, ",=+-"); |
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94 | token(sc); |
95 | if (sc->t == '=') |
96 | token(sc); |
97 | |
98 | if (sc->t != CTOK_WORD) |
99 | error(sc, "parse error, expected file mode"); |
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100 | conf_undelim(sc, 0, 0); |
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101 | |
102 | /* --- If it looks digitlike, read as octal --- */ |
103 | |
104 | if (isdigit((unsigned char)*sc->d.buf)) |
105 | mode = strtoul(sc->d.buf, 0, 8) & 07777; |
106 | |
107 | /* --- Otherise read as chmod-like characters --- */ |
108 | |
109 | else { |
110 | const char *p; |
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111 | unsigned mask = 04700; |
112 | unsigned state = 0; |
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113 | unsigned or = 1; |
114 | |
115 | /* --- Set the default from the umask --- */ |
116 | |
117 | { |
118 | unsigned um = umask(0); |
119 | umask(um); |
120 | mode = 0666 & ~um; |
121 | } |
122 | |
123 | /* --- Parse the characters --- * |
124 | * |
125 | * This is a particularly lenient implementation of the usual chmod- |
126 | * style mode language. |
127 | */ |
128 | |
129 | for (p = sc->d.buf; *p; p++) { |
130 | switch (*p) { |
131 | case ',': break; |
132 | |
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133 | case 'a': mask = (mask & state) | 07777; state = 07777; break; |
134 | case 'u': mask = (mask & state) | 04700; state = 07777; break; |
135 | case 'g': mask = (mask & state) | 02070; state = 07777; break; |
136 | case 'o': mask = (mask & state) | 01007; state = 07777; break; |
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137 | |
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138 | case '=': mode &= ~mask; /* Drop through */ |
139 | case '+': state = 0; or = 1; break; |
140 | case '-': state = 0; or = 0; break; |
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141 | |
142 | #define APPLY(m) if (or) mode |= ((m) & mask); else mode &= ~((m) & mask); |
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143 | case 'r': state = 0; APPLY(00444); break; |
144 | case 'w': state = 0; APPLY(00222); break; |
145 | case 'x': state = 0; APPLY(00111); break; |
146 | case 's': state = 0; APPLY(06000); break; |
147 | case 't': state = 0; APPLY(01000); break; |
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148 | #undef APPLY |
149 | |
150 | default: error(sc, "unknown mode character `%c'", *p); |
151 | } |
152 | } |
153 | } |
154 | |
155 | token(sc); |
156 | f->mode = mode; |
157 | CONF_ACCEPT; |
158 | } |
159 | |
160 | /* --- Read a file uid specification --- */ |
161 | |
162 | if (strcmp(sc->d.buf, "uid") == 0 || |
163 | strcmp(sc->d.buf, "user") == 0 || |
164 | strcmp(sc->d.buf, "owner") == 0) { |
165 | token(sc); |
166 | if (sc->t == '=') |
167 | token(sc); |
168 | if (sc->t != CTOK_WORD) |
169 | error(sc, "parse error, expected user name or uid"); |
170 | if (isdigit((unsigned char)*sc->d.buf)) |
171 | f->uid = atoi(sc->d.buf); |
172 | else { |
173 | struct passwd *pw = getpwnam(sc->d.buf); |
174 | if (!pw) |
175 | error(sc, "unknown user name `%s'", sc->d.buf); |
176 | f->uid = pw->pw_uid; |
177 | } |
178 | token(sc); |
179 | CONF_ACCEPT; |
180 | } |
181 | |
182 | /* --- Read a file gid specification --- */ |
183 | |
184 | if (strcmp(sc->d.buf, "gid") == 0 || |
185 | strcmp(sc->d.buf, "group") == 0) { |
186 | token(sc); |
187 | if (sc->t == '=') |
188 | token(sc); |
189 | if (sc->t != CTOK_WORD) |
190 | error(sc, "parse error, expected group name or gid"); |
191 | if (isdigit((unsigned char)*sc->d.buf)) |
192 | f->gid = atoi(sc->d.buf); |
193 | else { |
194 | struct group *gr = getgrnam(sc->d.buf); |
195 | if (!gr) |
196 | error(sc, "unknown user name `%s'", sc->d.buf); |
197 | f->gid = gr->gr_gid; |
198 | } |
199 | token(sc); |
200 | CONF_ACCEPT; |
201 | } |
202 | |
203 | /* --- Nothing here for me --- */ |
204 | |
205 | CONF_END; |
206 | } |
207 | |
208 | /* --- @fattr_apply@ --- * |
209 | * |
210 | * Arguments: @const char *file@ = pointer to filename |
211 | * @fattr *f@ = pointer to attribute set |
212 | * |
213 | * Returns: @-1@ if it failed. |
214 | * |
215 | * Use: Applies file attributes to a file. For best results, try to |
216 | * create the file with the right permissions and so on. This |
217 | * call will fix everything up, but there are potential races |
218 | * which might catch you out if you're not careful. |
219 | */ |
220 | |
221 | int fattr_apply(const char *file, fattr *f) |
222 | { |
223 | if (chown(file, f->uid, f->gid) == -1 || |
224 | chmod(file, f->mode) == -1) |
225 | return (-1); |
226 | return (0); |
227 | } |
228 | |
229 | /*----- That's all, folks -------------------------------------------------*/ |