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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/* Copyright (c) 1999 Anthony Towns
* Copyright (c) 2000 Matthias Klose
*
* You may freely use, distribute, and modify this program.
*/
// Don't rely on /bin/sh and popen!
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/wait.h>
/* XXX: evil kludge, deal with arbitrary name lengths */
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
int myexec(char *cmd, ...)
{
va_list ap;
pid_t child;
char *new_argv[10];
int new_argc = 0, i;
new_argv[new_argc++] = cmd;
va_start(ap, cmd);
while ((new_argv[new_argc++] = va_arg(ap, char *)));
va_end(ap);
switch(child = fork()) {
case -1:
/* fork failed */
return EXIT_FAILURE;
case 0:
/* i'm the child */
{
execv(cmd, new_argv);
_exit(127);
}
default:
/* i'm the parent */
{
int status;
pid_t pid;
pid = wait(&status);
if (pid == child) {
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
return EXIT_SUCCESS;
}
}
}
}
return EXIT_FAILURE;
}
int check_predepends(void)
{
return myexec("/usr/bin/dpkg", "--assert-support-predepends", NULL);
}
int dpkg_compare_versions(char *v1, char *op, char *v2)
{
return myexec("/usr/bin/dpkg", "--compare-versions", v1, op, v2, NULL);
}
int dpkg_divert_add(char *pkg, char *file)
{
return myexec("/usr/sbin/dpkg-divert", "--package", pkg, "--add", file, NULL);
}
char *check_diversion(char *diversion_name)
{
pid_t child;
int pipedes[2];
if (pipe(pipedes))
return NULL;
switch(child = fork()) {
case -1:
/* fork failed */
close(pipedes[0]);
close(pipedes[1]);
return NULL;
case 0:
/* i'm the child */
{
if (dup2(pipedes[STDOUT_FILENO], STDOUT_FILENO) < 0)
_exit(127);
close(pipedes[STDIN_FILENO]);
close(pipedes[STDOUT_FILENO]);
execl( "/usr/sbin/dpkg-divert", "/usr/sbin/dpkg-divert",
"--list", diversion_name, NULL );
_exit(127);
}
default:
/* i'm the parent */
{
static char line[1024];
FILE *fd;
close (pipedes[STDOUT_FILENO]);
fcntl (pipedes[STDIN_FILENO], F_SETFD, FD_CLOEXEC);
fd = fdopen (pipedes[STDIN_FILENO], "r");
while (fgets(line, 1024, fd) != NULL) {
line[strlen(line)-1] = '\0';
break;
}
fclose(fd);
return line;
}
}
return NULL;
}
#define FIRST_WITHOUT_SHLINK "2.05b-4"
const char *msg =
"As bash for Debian is destined to provide a working /bin/sh (pointing to\n"
"/bin/bash) your link will be overwritten by a default link.\n\n"
"If you don't want further upgrades to overwrite your customization,\n"
"please read /usr/share/doc/bash/README.Debian for a more permanent solution.\n\n"
"[Press RETURN to continue]";
int main(int argc, char *argv[]) {
int targetlen;
char target[PATH_MAX+1], answer[1024];
if (argc < 2) {
printf("\nbash/preinst: expected at least one argument\n\n");
return EXIT_FAILURE;
}
if (check_predepends() != EXIT_SUCCESS) {
printf("\nPlease upgrade to a new version of dpkg\n\n");
return EXIT_FAILURE;
}
/*
if [ "$1" = upgrade ] && dpkg --compare-versions "$2" lt FIRST_WITHOUT_SHLINK; then
div=$(dpkg-divert --list /bin/sh)
if [ -z "$div" ]; then
dpkg-divert --package bash --add /bin/sh
ln -sf dash /bin/sh
fi
div=$(dpkg-divert --list /usr/share/man/man1/sh.1.gz)
if [ -z "$div" ]; then
dpkg-divert --package bash --add /usr/share/man/man1/sh.1.gz
ln -sf dash.1.gz /usr/share/man/man1/sh.1.gz
fi
fi
*/
if (strcmp(argv[1], "upgrade") == 0) {
if (argc < 3) {
printf("\nbash/preinst upgrade: expected at least two arguments\n\n");
return EXIT_FAILURE;
}
if (dpkg_compare_versions(argv[2], "lt", FIRST_WITHOUT_SHLINK) == EXIT_SUCCESS) {
char *diversion = check_diversion("/bin/sh");
if (diversion == NULL)
return EXIT_FAILURE;
// printf("diversion: /%s/\n", diversion);
if (strcmp(diversion, "") == 0) {
// link is not diverted
dpkg_divert_add("bash", "/bin/sh");
unlink("/bin/sh");
symlink("dash", "/bin/sh");
}
diversion = check_diversion("/usr/share/man/man1/sh.1.gz");
if (diversion == NULL)
return EXIT_FAILURE;
// printf("diversion: /%s/\n", diversion);
if (strcmp(diversion, "") == 0) {
// link is not diverted
dpkg_divert_add("bash", "/usr/share/man/man1/sh.1.gz");
unlink("/usr/share/man/man1/sh.1.gz");
symlink("dash.1.gz", "/usr/share/man/man1/sh.1.gz");
}
}
}
#if 0
targetlen = readlink("/bin/sh", target, PATH_MAX);
if (targetlen == -1) {
// error reading link. Will be overwritten.
puts("The bash upgrade discovered that something is wrong with your /bin/sh link.");
puts(msg);
fgets(answer, 1024, stdin);
return EXIT_SUCCESS;
}
target[targetlen] = '\0';
if (strcmp(target, "bash") != 0 && strcmp(target, "/bin/bash") != 0) {
char *diversion = check_diversion("/bin/sh");
if (diversion == NULL)
return EXIT_FAILURE;
// printf("diversion: /%s/\n", diversion);
if (strcmp(diversion, "") != 0)
// link is diverted
return EXIT_SUCCESS;
printf("The bash upgrade discovered that your /bin/sh link points to %s.\n", target);
puts(msg);
fgets(answer, 1024, stdin);
return EXIT_SUCCESS;
}
#endif
return EXIT_SUCCESS;
}
|
