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
|
/*******************************************************************/
/* slibtool: a skinny libtool implementation, written in C */
/* Copyright (C) 2016--2018 Z. Gilboa */
/* Released under the Standard MIT License; see COPYING.SLIBTOOL. */
/*******************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include "slibtool_driver_impl.h"
#include "slibtool_errinfo_impl.h"
#include "slibtool_symlink_impl.h"
#include "slibtool_readlink_impl.h"
#define SLBT_DEV_NULL_FLAGS (SLBT_DRIVER_ALL_STATIC \
| SLBT_DRIVER_DISABLE_SHARED \
| SLBT_DRIVER_DISABLE_STATIC)
int slbt_create_symlink(
const struct slbt_driver_ctx * dctx,
struct slbt_exec_ctx * ectx,
const char * target,
const char * lnkname,
bool flawrapper)
{
int fdcwd;
char ** oargv;
const char * slash;
char * ln[5];
char * dotdot;
char tmplnk [PATH_MAX];
char lnkarg [PATH_MAX];
char alnkarg[PATH_MAX];
char atarget[PATH_MAX];
char * suffix = 0;
/* symlink is a placeholder? */
if ((dctx->cctx->drvflags & SLBT_DEV_NULL_FLAGS)
&& !strcmp(target,"/dev/null")) {
slash = target;
suffix = ".disabled";
/* symlink target contains a dirname? */
} else if ((slash = strrchr(target,'/'))) {
slash++;
/* symlink target is a basename */
} else {
slash = target;
}
/* .la wrapper? */
dotdot = flawrapper ? "../" : "";
/* atarget */
if ((size_t)snprintf(atarget,sizeof(atarget),"%s%s",
dotdot,slash) >= sizeof(atarget))
return SLBT_BUFFER_ERROR(dctx);
/* tmplnk */
if ((size_t)snprintf(tmplnk,sizeof(tmplnk),"%s.symlink.tmp",
lnkname) >= sizeof(tmplnk))
return SLBT_BUFFER_ERROR(dctx);
/* placeholder? */
if (suffix) {
sprintf(alnkarg,"%s%s",lnkname,suffix);
lnkname = alnkarg;
}
/* lnkarg */
strcpy(lnkarg,lnkname);
/* ln argv (fake) */
ln[0] = "ln";
ln[1] = "-s";
ln[2] = atarget;
ln[3] = lnkarg;
ln[4] = 0;
oargv = ectx->argv;
ectx->argv = ln;
/* step output */
if (!(dctx->cctx->drvflags & SLBT_DRIVER_SILENT)) {
if (dctx->cctx->mode == SLBT_MODE_LINK) {
if (slbt_output_link(dctx,ectx)) {
ectx->argv = oargv;
return SLBT_NESTED_ERROR(dctx);
}
} else {
if (slbt_output_install(dctx,ectx)) {
ectx->argv = oargv;
return SLBT_NESTED_ERROR(dctx);
}
}
}
/* restore execution context */
ectx->argv = oargv;
/* fdcwd */
fdcwd = slbt_driver_fdcwd(dctx);
/* create symlink */
if (symlinkat(atarget,fdcwd,tmplnk))
return SLBT_SYSTEM_ERROR(dctx,tmplnk);
return renameat(fdcwd,tmplnk,fdcwd,lnkname)
? SLBT_SYSTEM_ERROR(dctx,lnkname)
: 0;
}
int slbt_symlink_is_a_placeholder(int fdcwd, char * lnkpath)
{
size_t len;
char slink [PATH_MAX];
char target[PATH_MAX];
const char suffix[] = ".disabled";
if ((sizeof(slink)-sizeof(suffix)) < (len=strlen(lnkpath)))
return 0;
memcpy(slink,lnkpath,len);
memcpy(&slink[len],suffix,sizeof(suffix));
return (!slbt_readlinkat(fdcwd,slink,target,sizeof(target)))
&& (!strcmp(target,"/dev/null"));
}
|
