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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: fattr.c,v 1.4 2004/04/08 01:36:25 mdw Exp $ |
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4 | * |
5 | * Handling of file attributes |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the `fw' port forwarder. |
13 | * |
14 | * `fw' is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * `fw' is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with `fw'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
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29 | /*----- Header files ------------------------------------------------------*/ |
30 | |
31 | #include "config.h" |
32 | |
33 | #include <ctype.h> |
34 | #include <errno.h> |
35 | #include <stdio.h> |
36 | #include <stdlib.h> |
37 | #include <string.h> |
38 | |
39 | #include <sys/types.h> |
40 | #include <sys/stat.h> |
41 | #include <unistd.h> |
42 | |
43 | #include <pwd.h> |
44 | #include <grp.h> |
45 | |
46 | #include "conf.h" |
47 | #include "fattr.h" |
48 | #include "scan.h" |
49 | |
50 | /*----- Global variables --------------------------------------------------*/ |
51 | |
52 | fattr fattr_global; |
53 | |
54 | /*----- Main code ---------------------------------------------------------*/ |
55 | |
56 | /* --- @fattr_init@ --- * |
57 | * |
58 | * Arguments: @fattr *f@ = pointer to file attributes |
59 | * |
60 | * Returns: --- |
61 | * |
62 | * Use: Initializes a set of file attributes to default values. |
63 | */ |
64 | |
65 | void fattr_init(fattr *f) |
66 | { |
67 | unsigned um = umask(0); |
68 | umask(um); |
69 | f->mode = 0666 & ~um; |
70 | f->uid = -1; |
71 | f->gid = -1; |
72 | } |
73 | |
74 | /* --- @fattr_option@ --- * |
75 | * |
76 | * Arguments: @scanner *sc@ = pointer to scanner to read |
77 | * @fattr *f@ = pointer to file attributes to set |
78 | * |
79 | * Returns: Whether the option was claimed. |
80 | * |
81 | * Use: Reads file attributes from a scanner. |
82 | */ |
83 | |
84 | int fattr_option(scanner *sc, fattr *f) |
85 | { |
86 | CONF_BEGIN(sc, "fattr", "file attribute") |
87 | |
88 | /* --- Read a file mode specification --- */ |
89 | |
90 | if (strcmp(sc->d.buf, "mode") == 0) { |
91 | unsigned mode = 0; |
92 | |
93 | /* --- Gobble an optional `=' sign --- */ |
94 | |
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95 | conf_undelim(sc, 0, ",=+-"); |
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96 | token(sc); |
97 | if (sc->t == '=') |
98 | token(sc); |
99 | |
100 | if (sc->t != CTOK_WORD) |
101 | error(sc, "parse error, expected file mode"); |
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102 | conf_undelim(sc, 0, 0); |
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103 | |
104 | /* --- If it looks digitlike, read as octal --- */ |
105 | |
106 | if (isdigit((unsigned char)*sc->d.buf)) |
107 | mode = strtoul(sc->d.buf, 0, 8) & 07777; |
108 | |
109 | /* --- Otherise read as chmod-like characters --- */ |
110 | |
111 | else { |
112 | const char *p; |
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113 | unsigned mask = 04700; |
114 | unsigned state = 0; |
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115 | unsigned or = 1; |
116 | |
117 | /* --- Set the default from the umask --- */ |
118 | |
119 | { |
120 | unsigned um = umask(0); |
121 | umask(um); |
122 | mode = 0666 & ~um; |
123 | } |
124 | |
125 | /* --- Parse the characters --- * |
126 | * |
127 | * This is a particularly lenient implementation of the usual chmod- |
128 | * style mode language. |
129 | */ |
130 | |
131 | for (p = sc->d.buf; *p; p++) { |
132 | switch (*p) { |
133 | case ',': break; |
134 | |
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135 | case 'a': mask = (mask & state) | 07777; state = 07777; break; |
136 | case 'u': mask = (mask & state) | 04700; state = 07777; break; |
137 | case 'g': mask = (mask & state) | 02070; state = 07777; break; |
138 | case 'o': mask = (mask & state) | 01007; state = 07777; break; |
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139 | |
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140 | case '=': mode &= ~mask; /* Drop through */ |
141 | case '+': state = 0; or = 1; break; |
142 | case '-': state = 0; or = 0; break; |
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143 | |
144 | #define APPLY(m) if (or) mode |= ((m) & mask); else mode &= ~((m) & mask); |
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145 | case 'r': state = 0; APPLY(00444); break; |
146 | case 'w': state = 0; APPLY(00222); break; |
147 | case 'x': state = 0; APPLY(00111); break; |
148 | case 's': state = 0; APPLY(06000); break; |
149 | case 't': state = 0; APPLY(01000); break; |
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150 | #undef APPLY |
151 | |
152 | default: error(sc, "unknown mode character `%c'", *p); |
153 | } |
154 | } |
155 | } |
156 | |
157 | token(sc); |
158 | f->mode = mode; |
159 | CONF_ACCEPT; |
160 | } |
161 | |
162 | /* --- Read a file uid specification --- */ |
163 | |
164 | if (strcmp(sc->d.buf, "uid") == 0 || |
165 | strcmp(sc->d.buf, "user") == 0 || |
166 | strcmp(sc->d.buf, "owner") == 0) { |
167 | token(sc); |
168 | if (sc->t == '=') |
169 | token(sc); |
170 | if (sc->t != CTOK_WORD) |
171 | error(sc, "parse error, expected user name or uid"); |
172 | if (isdigit((unsigned char)*sc->d.buf)) |
173 | f->uid = atoi(sc->d.buf); |
174 | else { |
175 | struct passwd *pw = getpwnam(sc->d.buf); |
176 | if (!pw) |
177 | error(sc, "unknown user name `%s'", sc->d.buf); |
178 | f->uid = pw->pw_uid; |
179 | } |
180 | token(sc); |
181 | CONF_ACCEPT; |
182 | } |
183 | |
184 | /* --- Read a file gid specification --- */ |
185 | |
186 | if (strcmp(sc->d.buf, "gid") == 0 || |
187 | strcmp(sc->d.buf, "group") == 0) { |
188 | token(sc); |
189 | if (sc->t == '=') |
190 | token(sc); |
191 | if (sc->t != CTOK_WORD) |
192 | error(sc, "parse error, expected group name or gid"); |
193 | if (isdigit((unsigned char)*sc->d.buf)) |
194 | f->gid = atoi(sc->d.buf); |
195 | else { |
196 | struct group *gr = getgrnam(sc->d.buf); |
197 | if (!gr) |
198 | error(sc, "unknown user name `%s'", sc->d.buf); |
199 | f->gid = gr->gr_gid; |
200 | } |
201 | token(sc); |
202 | CONF_ACCEPT; |
203 | } |
204 | |
205 | /* --- Nothing here for me --- */ |
206 | |
207 | CONF_END; |
208 | } |
209 | |
210 | /* --- @fattr_apply@ --- * |
211 | * |
212 | * Arguments: @const char *file@ = pointer to filename |
213 | * @fattr *f@ = pointer to attribute set |
214 | * |
215 | * Returns: @-1@ if it failed. |
216 | * |
217 | * Use: Applies file attributes to a file. For best results, try to |
218 | * create the file with the right permissions and so on. This |
219 | * call will fix everything up, but there are potential races |
220 | * which might catch you out if you're not careful. |
221 | */ |
222 | |
223 | int fattr_apply(const char *file, fattr *f) |
224 | { |
225 | if (chown(file, f->uid, f->gid) == -1 || |
226 | chmod(file, f->mode) == -1) |
227 | return (-1); |
228 | return (0); |
229 | } |
230 | |
231 | /*----- That's all, folks -------------------------------------------------*/ |