Urlader/urlib.c

#include "urlib.h"

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#ifdef _WIN32

  #include <windows.h>
  //#include <winbase.h>
  #include <shlobj.h>
  #include <shlwapi.h>
  #include <wininet.h>

  static DWORD dword;

  #define u_handle HANDLE
  #define u_invalid_handle 0
  #define u_valid(handle) (!!handle)

  #define u_setenv(name,value) SetEnvironmentVariable (name, value)
  #define u_mkdir(path) !CreateDirectory (path, NULL)
  #define u_chdir(path) !SetCurrentDirectory (path)
  #define u_rename(fr,to) !MoveFile (fr, to)
  #define u_open(path) CreateFile (path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_close(handle) CloseHandle (handle)
  #define u_append(path,add) PathAppend (path, add)
  #define u_write(handle,data,len) (WriteFile (handle, data, len, &dword, 0) ? dword : -1)

  #define u_fsync(handle) FlushFileBuffers (handle)
  #define u_sync()

  #define u_lockfile(path) CreateFile (path, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)
  #define u_cloexec(handle)

#else

  #define _GNU_SOURCE 1
  #define _BSD_SOURCE 1
  // the above increases our chances of getting MAP_ANONYMOUS

  #include <sys/mman.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <pwd.h>

  #if defined (MAP_ANON) && !defined (MAP_ANONYMOUS)
    #define MAP_ANONYMOUS MAP_ANON
  #endif

  #ifdef PATH_MAX
    #define MAX_PATH (PATH_MAX < 4096 ? 4096 : PATH_MAX)
  #else
    #define MAX_PATH 4096
  #endif

  #define u_handle int
  #define u_invalid_handle -1
  #define u_valid(fd) ((fd) >= 0)

  #define u_setenv(name,value) setenv (name, value, 1)
  #define u_mkdir(path) mkdir (path, 0777)
  #define u_chdir(path) chdir (path)
  #define u_rename(fr,to) rename (fr, to)
  #define u_open(path) open (path, O_RDONLY)
  #define u_creat(path,exec) open (path, O_WRONLY | O_CREAT | O_TRUNC, (exec) ? 0777 : 0666)
  #define u_close(handle) close (handle)
  #define u_append(path,add) strcat (strcat (path, "/"), add)
  #define u_write(handle,data,len) write (handle, data, len)

  // on a mostly idle system, a sync at the end is certainly faster, hope for the best
  #define u_fsync(handle)
  #define u_sync() sync ()

  #define u_lockfile(path) open (path, O_RDWR | O_CREAT, 0666)
  #define u_cloexec(handle) fcntl (handle, F_SETFD, FD_CLOEXEC)

#endif

#define u_16(ptr) (((ptr)[0] << 8) | (ptr)[1])
#define u_32(ptr) (((ptr)[0] << 24) | ((ptr)[1] << 16) | ((ptr)[2] << 8) | (ptr)[3])

static char currdir[MAX_PATH];
static char datadir[MAX_PATH];  // %AppData%/urlader
static char exe_dir[MAX_PATH];  // %AppData%/urlader/EXE_ID
static char execdir[MAX_PATH];  // %AppData%/urlader/EXE_ID/EXE_VER
static char exe_id[MAX_PATH];
static char exe_ver[MAX_PATH];

/////////////////////////////////////////////////////////////////////////////

static void
u_fatal (const char *msg)
{
#ifdef _WIN32
  MessageBox (0, msg, URLADER, 0);
#else
  write (2, URLADER ": ", sizeof (URLADER ": ") - 1);
  write (2, msg, strlen (msg));
  write (2, "\n", 1);
#endif

  _exit (1);
}

static void *
u_malloc (unsigned int size)
{
  void *addr;

#ifdef _WIN32
  HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);

  if (!handle)
    return 0;

  addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);

  CloseHandle (handle);
#elif defined (MAP_ANONYMOUS)
  addr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);

  if (addr == (void *)-1)
    addr = 0;
#else
  addr = malloc (size);
#endif

  return addr;
}

static void
u_free (void *addr, unsigned int size)
{
#ifdef _WIN32
  UnmapViewOfFile (addr);
#elif defined (MAP_ANONYMOUS)
  munmap (addr, size);
#else
  free (addr);
#endif
}

static void *
u_mmap (u_handle h, unsigned int size)
{
  void *addr;

#ifdef _WIN32
  HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);

  if (!handle)
    return 0;

  addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);

  CloseHandle (handle);
#else
  addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);

  if (addr == (void *)-1)
    addr = 0;
#endif

  return addr;
}

static void
u_munmap (void *addr, unsigned int len)
{
#ifdef _WIN32
  UnmapViewOfFile (addr);
#else
  munmap (addr, len);
#endif
}

/////////////////////////////////////////////////////////////////////////////

static void
u_set_datadir (void)
{
#ifdef _WIN32
  if (SHGetFolderPath (0, CSIDL_APPDATA | CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
    u_fatal ("unable to find application data directory");

  u_mkdir (datadir);
  u_append (datadir, URLADER);

#else
  char *home = getenv ("HOME");

  if (!home)
    {
      struct passwd *pw;

      if ((pw = getpwuid (getuid ())))
        home = pw->pw_dir;
      else
        home = "/tmp";
    }

  u_mkdir (home);
  //strcat (strcat (strcpy (datadir, home), "/."), URLADER);
  sprintf (datadir, "%s/.%s", home, URLADER);
#endif

  u_setenv ("URLADER_DATADIR", datadir);
}

static void
u_set_exe_info (void)
{
  strcpy (exe_dir, datadir);
  u_append (exe_dir, exe_id);
  u_mkdir (exe_dir);

  strcpy (execdir, exe_dir);
  u_append (execdir, "i-");
  strcat (execdir, exe_ver);

  u_setenv ("URLADER_EXECDIR", execdir);
  u_setenv ("URLADER_EXE_ID" , exe_id);
  u_setenv ("URLADER_EXE_DIR", exe_dir);
  u_setenv ("URLADER_EXE_VER", exe_ver);
}

/////////////////////////////////////////////////////////////////////////////

static u_handle
u_lock (const char *path, int excl, int dowait)
{
  u_handle h;

  h = u_lockfile (path);
  if (!u_valid (h))
    return h;

  u_cloexec (h);

  for (;;)
    {
      int success;

      // acquire the lock
#ifdef _WIN32
      OVERLAPPED ov = { 0 };

      success = LockFileEx (h,
                            (excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
                            | (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
                            0,
                            1, 0,
                            &ov);
#else
      struct flock lck = { 0 };

      lck.l_type   = excl ? F_WRLCK : F_RDLCK;
      lck.l_whence = SEEK_SET;
      lck.l_len    = 1;

      success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
#endif

      if (!success)
        break;

      // we have the lock, now verify that the lockfile still exists

#ifdef _WIN32
      // apparently, we have to open the file to get its info :(
      {
        BY_HANDLE_FILE_INFORMATION s1, s2;
        u_handle h2 = u_lockfile (path);
        if (!u_valid (h))
          break;

        success = GetFileInformationByHandle (h, &s1)
                  && GetFileInformationByHandle (h2, &s2);

        u_close (h2);

        if (!success)
          break;

        success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
               && s1.nFileIndexHigh       == s2.nFileIndexHigh
               && s1.nFileIndexLow        == s2.nFileIndexLow;
      }
#else
      struct stat s1, s2;

      if (fstat (h, &s1) || stat (path, &s2))
        break;

      success = s1.st_dev == s2.st_dev
             && s1.st_ino == s2.st_ino;
#endif

      if (success)
        return h; // lock successfully acquired

      // files differ, close and retry - should be very rare
      u_close (h);
    }

  // failure
  u_close (h);
  return u_invalid_handle;
}

Revision:	1.2
Committed:	Mon Jan 2 09:23:04 2012 UTC (12 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.1:	+97 -16 lines
Log Message:	* empty log message *
#	Content
1	#include "urlib.h"
2
3	#include <fcntl.h>
4	#include <stdio.h>
5	#include <string.h>
6	#include <stdlib.h>
7
8	#ifdef _WIN32
9
10	#include <windows.h>
11	//#include <winbase.h>
12	#include <shlobj.h>
13	#include <shlwapi.h>
14	#include <wininet.h>
15
16	static DWORD dword;
17
18	#define u_handle HANDLE
19	#define u_invalid_handle 0
20	#define u_valid(handle) (!!handle)
21
22	#define u_setenv(name,value) SetEnvironmentVariable (name, value)
23	#define u_mkdir(path) !CreateDirectory (path, NULL)
24	#define u_chdir(path) !SetCurrentDirectory (path)
25	#define u_rename(fr,to) !MoveFile (fr, to)
26	#define u_open(path) CreateFile (path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
27	#define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
28	#define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
29	#define u_close(handle) CloseHandle (handle)
30	#define u_append(path,add) PathAppend (path, add)
31	#define u_write(handle,data,len) (WriteFile (handle, data, len, &dword, 0) ? dword : -1)
32
33	#define u_fsync(handle) FlushFileBuffers (handle)
34	#define u_sync()
35
36	#define u_lockfile(path) CreateFile (path, GENERIC_READ \| GENERIC_WRITE, FILE_SHARE_READ \| FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)
37	#define u_cloexec(handle)
38
39	#else
40
41	#define _GNU_SOURCE 1
42	#define _BSD_SOURCE 1
43	// the above increases our chances of getting MAP_ANONYMOUS
44
45	#include <sys/mman.h>
46	#include <sys/types.h>
47	#include <sys/stat.h>
48	#include <unistd.h>
49	#include <pwd.h>
50
51	#if defined (MAP_ANON) && !defined (MAP_ANONYMOUS)
52	#define MAP_ANONYMOUS MAP_ANON
53	#endif
54
55	#ifdef PATH_MAX
56	#define MAX_PATH (PATH_MAX < 4096 ? 4096 : PATH_MAX)
57	#else
58	#define MAX_PATH 4096
59	#endif
60
61	#define u_handle int
62	#define u_invalid_handle -1
63	#define u_valid(fd) ((fd) >= 0)
64
65	#define u_setenv(name,value) setenv (name, value, 1)
66	#define u_mkdir(path) mkdir (path, 0777)
67	#define u_chdir(path) chdir (path)
68	#define u_rename(fr,to) rename (fr, to)
69	#define u_open(path) open (path, O_RDONLY)
70	#define u_creat(path,exec) open (path, O_WRONLY \| O_CREAT \| O_TRUNC, (exec) ? 0777 : 0666)
71	#define u_close(handle) close (handle)
72	#define u_append(path,add) strcat (strcat (path, "/"), add)
73	#define u_write(handle,data,len) write (handle, data, len)
74
75	// on a mostly idle system, a sync at the end is certainly faster, hope for the best
76	#define u_fsync(handle)
77	#define u_sync() sync ()
78
79	#define u_lockfile(path) open (path, O_RDWR \| O_CREAT, 0666)
80	#define u_cloexec(handle) fcntl (handle, F_SETFD, FD_CLOEXEC)
81
82	#endif
83
84	#define u_16(ptr) (((ptr)[0] << 8) \| (ptr)[1])
85	#define u_32(ptr) (((ptr)[0] << 24) \| ((ptr)[1] << 16) \| ((ptr)[2] << 8) \| (ptr)[3])
86
87	static char currdir[MAX_PATH];
88	static char datadir[MAX_PATH]; // %AppData%/urlader
89	static char exe_dir[MAX_PATH]; // %AppData%/urlader/EXE_ID
90	static char execdir[MAX_PATH]; // %AppData%/urlader/EXE_ID/EXE_VER
91	static char exe_id[MAX_PATH];
92	static char exe_ver[MAX_PATH];
93
94	/////////////////////////////////////////////////////////////////////////////
95
96	static void
97	u_fatal (const char *msg)
98	{
99	#ifdef _WIN32
100	MessageBox (0, msg, URLADER, 0);
101	#else
102	write (2, URLADER ": ", sizeof (URLADER ": ") - 1);
103	write (2, msg, strlen (msg));
104	write (2, "\n", 1);
105	#endif
106
107	_exit (1);
108	}
109
110	static void *
111	u_malloc (unsigned int size)
112	{
113	void *addr;
114
115	#ifdef _WIN32
116	HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);
117
118	if (!handle)
119	return 0;
120
121	addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);
122
123	CloseHandle (handle);
124	#elif defined (MAP_ANONYMOUS)
125	addr = mmap (0, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANON, -1, 0);
126
127	if (addr == (void *)-1)
128	addr = 0;
129	#else
130	addr = malloc (size);
131	#endif
132
133	return addr;
134	}
135
136	static void
137	u_free (void *addr, unsigned int size)
138	{
139	#ifdef _WIN32
140	UnmapViewOfFile (addr);
141	#elif defined (MAP_ANONYMOUS)
142	munmap (addr, size);
143	#else
144	free (addr);
145	#endif
146	}
147
148	static void *
149	u_mmap (u_handle h, unsigned int size)
150	{
151	void *addr;
152
153	#ifdef _WIN32
154	HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);
155
156	if (!handle)
157	return 0;
158
159	addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);
160
161	CloseHandle (handle);
162	#else
163	addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);
164
165	if (addr == (void *)-1)
166	addr = 0;
167	#endif
168
169	return addr;
170	}
171
172	static void
173	u_munmap (void *addr, unsigned int len)
174	{
175	#ifdef _WIN32
176	UnmapViewOfFile (addr);
177	#else
178	munmap (addr, len);
179	#endif
180	}
181
182	/////////////////////////////////////////////////////////////////////////////
183
184	static void
185	u_set_datadir (void)
186	{
187	#ifdef _WIN32
188	if (SHGetFolderPath (0, CSIDL_APPDATA \| CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
189	u_fatal ("unable to find application data directory");
190
191	u_mkdir (datadir);
192	u_append (datadir, URLADER);
193
194	#else
195	char *home = getenv ("HOME");
196
197	if (!home)
198	{
199	struct passwd *pw;
200
201	if ((pw = getpwuid (getuid ())))
202	home = pw->pw_dir;
203	else
204	home = "/tmp";
205	}
206
207	u_mkdir (home);
208	//strcat (strcat (strcpy (datadir, home), "/."), URLADER);
209	sprintf (datadir, "%s/.%s", home, URLADER);
210	#endif
211
212	u_setenv ("URLADER_DATADIR", datadir);
213	}
214
215	static void
216	u_set_exe_info (void)
217	{
218	strcpy (exe_dir, datadir);
219	u_append (exe_dir, exe_id);
220	u_mkdir (exe_dir);
221
222	strcpy (execdir, exe_dir);
223	u_append (execdir, "i-");
224	strcat (execdir, exe_ver);
225
226	u_setenv ("URLADER_EXECDIR", execdir);
227	u_setenv ("URLADER_EXE_ID" , exe_id);
228	u_setenv ("URLADER_EXE_DIR", exe_dir);
229	u_setenv ("URLADER_EXE_VER", exe_ver);
230	}
231
232	/////////////////////////////////////////////////////////////////////////////
233
234	static u_handle
235	u_lock (const char *path, int excl, int dowait)
236	{
237	u_handle h;
238
239	h = u_lockfile (path);
240	if (!u_valid (h))
241	return h;
242
243	u_cloexec (h);
244
245	for (;;)
246	{
247	int success;
248
249	// acquire the lock
250	#ifdef _WIN32
251	OVERLAPPED ov = { 0 };
252
253	success = LockFileEx (h,
254	(excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
255	\| (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
256	0,
257	1, 0,
258	&ov);
259	#else
260	struct flock lck = { 0 };
261
262	lck.l_type = excl ? F_WRLCK : F_RDLCK;
263	lck.l_whence = SEEK_SET;
264	lck.l_len = 1;
265
266	success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
267	#endif
268
269	if (!success)
270	break;
271
272	// we have the lock, now verify that the lockfile still exists
273
274	#ifdef _WIN32
275	// apparently, we have to open the file to get its info :(
276	{
277	BY_HANDLE_FILE_INFORMATION s1, s2;
278	u_handle h2 = u_lockfile (path);
279	if (!u_valid (h))
280	break;
281
282	success = GetFileInformationByHandle (h, &s1)
283	&& GetFileInformationByHandle (h2, &s2);
284
285	u_close (h2);
286
287	if (!success)
288	break;
289
290	success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
291	&& s1.nFileIndexHigh == s2.nFileIndexHigh
292	&& s1.nFileIndexLow == s2.nFileIndexLow;
293	}
294	#else
295	struct stat s1, s2;
296
297	if (fstat (h, &s1) \|\| stat (path, &s2))
298	break;
299
300	success = s1.st_dev == s2.st_dev
301	&& s1.st_ino == s2.st_ino;
302	#endif
303
304	if (success)
305	return h; // lock successfully acquired
306
307	// files differ, close and retry - should be very rare
308	u_close (h);
309	}
310
311	// failure
312	u_close (h);
313	return u_invalid_handle;
314	}
315