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
|
#include "actual_function.h"
#include "utility/io.h"
#include "utility/logger.h"
#include "tracking/path_matcher.h"
#include "tracking/change_tracker.h"
// `true` signals the interposed functions to execute tracking logic
// `false` signals the interposed functions to do plain forwarding
static bool enabled = false;
static std::unique_ptr<utility::FileDescriptorGuard> fd_guard;
static std::unique_ptr<utility::Logger> logger;
static std::unique_ptr<tracking::PathMatcher> matcher;
static std::unique_ptr<tracking::ChangeTracker> tracker;
void init() __attribute__ ((constructor));
void init() {
if ( getenv("CHANGE_LOG_TARGET") != NULL ) {
fd_guard = std::make_unique<utility::FileDescriptorGuard>(
getenv("CHANGE_LOG_TARGET")
);
logger = std::make_unique<utility::Logger>(*fd_guard);
} else {
logger = std::make_unique<utility::Logger>(STDERR_FILENO);
}
if ( getenv("CHANGE_LOG_DIFF_CMD") != NULL ) {
tracker = std::make_unique<tracking::ChangeTracker>(
logger.get(), getenv("CHANGE_LOG_DIFF_CMD")
);
} else {
tracker = std::make_unique<tracking::ChangeTracker>(logger.get());
}
if ( getenv("CHANGE_LOG_IGNORE_PATTERN_PATH") != NULL ) {
matcher = std::make_unique<tracking::PathMatcher>(
getenv("CHANGE_LOG_IGNORE_PATTERN_PATH")
);
} else {
matcher = std::make_unique<tracking::PathMatcher>();
}
// tracking is only enabled when everything is initialized as both
// the actual tracking and the decision if a event should be tracked
// depend on `logger` and `tracker` being fully instantiated.
// In most cases this library will work correctly without delayed
// activation but e.g. `nvim` crashes as it performs tracked syscalls
// before `init` has been called.
enabled = true;
}
inline void track_write(const int fd) {
if ( enabled && fd != *fd_guard && utility::is_regular_file(fd) ) {
const auto path = utility::get_file_path(fd);
if ( !matcher->isMatching(path) ) {
tracker->track(path);
}
}
}
inline void track_rename(
const std::string& old_path, const std::string& new_path) {
if ( enabled ) {
if ( !matcher->isMatching(old_path) ) {
tracker->track(old_path);
if ( !matcher->isMatching(new_path) ) {
logger->append("renamed '", old_path, "' to '", new_path, "'");
}
}
}
}
inline void track_remove(const std::string& path) {
if ( enabled && utility::is_regular_file(path.c_str()) ) {
if ( !matcher->isMatching(path) ) {
logger->append("removed '", path, "'");
}
}
}
ssize_t write(int fd, const void* buffer, size_t count) {
track_write(fd);
return actual::write(fd, buffer, count);
}
ssize_t writev(int fd, const iovec* iov, int iovcnt) {
track_write(fd);
return actual::writev(fd, iov, iovcnt);
}
void* mmap(void* addr, size_t length, int prot, int flags, int fd, off_t offset) {
if ( prot & PROT_WRITE ) {
track_write(fd);
}
return actual::mmap(addr, length, prot, flags, fd, offset);
}
int rename(const char* old_path, const char* new_path) {
track_rename(old_path, new_path);
return actual::rename(old_path, new_path);
}
int rmdir(const char* path) {
track_remove(path);
return actual::rmdir(path);
}
int unlink(const char* path) {
track_remove(path);
return actual::unlink(path);
}
int unlinkat(int dirfd, const char* path, int flags) {
if ( dirfd == AT_FDCWD ) {
track_remove(path);
} else {
track_remove(utility::get_file_path(dirfd) + path);
}
return actual::unlinkat(dirfd, path, flags);
}
|
