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;

  if (!size)
    return 0;

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

  addr = 0;
  if (handle)
    {
      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

  if (!addr)
    u_fatal ("memory allocation failure, aborting.");

  return addr;
}

static void
u_free (void *addr, unsigned int size)
{
  if (!addr)
    return;

#ifdef _WIN32
  UnmapViewOfFile (addr);
#elif defined (MAP_ANONYMOUS)
  munmap (addr, size);
#else
  free (addr);
#endif
}

static void *
u_realloc (void *addr, unsigned int old_size, unsigned int new_size)
{
  void *addr2 = u_malloc (new_size);
  memcpy (addr2, addr, (new_size < old_size ? new_size : old_size));
  u_free (addr, old_size);

  return addr2;
}

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
}

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

typedef struct
{
  char *addr;
  unsigned int used;
  unsigned int size;
} u_dynbuf;

static void *
u_dynbuf_append (u_dynbuf *dynbuf, void *data, unsigned int len)
{
  char *dest;

  if ((dynbuf->used += len) > dynbuf->size)
    {
      unsigned int new_size = dynbuf->size ? dynbuf->size * 2 : 4096;
      dynbuf->addr = u_realloc (dynbuf->addr, dynbuf->size, new_size);
      dynbuf->size = new_size;
    }

  dest = dynbuf->addr + dynbuf->used - len;

  if (data)
    memcpy (dest, data, len);

  return dest;
}

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

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:	1.3
Committed:	Fri Jan 6 07:56:36 2012 UTC (12 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+54 -6 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "urlib.h"
2
3			#include <fcntl.h>
4	root	1.2	#include <stdio.h>
5			#include <string.h>
6			#include <stdlib.h>
7	root	1.1
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	root	1.2	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	root	1.1	static void *
111			u_malloc (unsigned int size)
112			{
113			void *addr;
114
115	root	1.3	if (!size)
116			return 0;
117
118	root	1.1	#ifdef _WIN32
119			HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);
120
121	root	1.3	addr = 0;
122			if (handle)
123			{
124			addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);
125			CloseHandle (handle);
126			}
127	root	1.1	#elif defined (MAP_ANONYMOUS)
128			addr = mmap (0, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANON, -1, 0);
129
130			if (addr == (void *)-1)
131			addr = 0;
132			#else
133			addr = malloc (size);
134			#endif
135
136	root	1.3	if (!addr)
137			u_fatal ("memory allocation failure, aborting.");
138
139	root	1.1	return addr;
140			}
141
142			static void
143			u_free (void *addr, unsigned int size)
144			{
145	root	1.3	if (!addr)
146			return;
147
148	root	1.1	#ifdef _WIN32
149			UnmapViewOfFile (addr);
150			#elif defined (MAP_ANONYMOUS)
151			munmap (addr, size);
152			#else
153			free (addr);
154			#endif
155			}
156
157			static void *
158	root	1.3	u_realloc (void *addr, unsigned int old_size, unsigned int new_size)
159			{
160			void *addr2 = u_malloc (new_size);
161			memcpy (addr2, addr, (new_size < old_size ? new_size : old_size));
162			u_free (addr, old_size);
163
164			return addr2;
165			}
166
167			static void *
168	root	1.1	u_mmap (u_handle h, unsigned int size)
169			{
170			void *addr;
171
172			#ifdef _WIN32
173			HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);
174
175			if (!handle)
176			return 0;
177
178			addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);
179
180			CloseHandle (handle);
181			#else
182			addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);
183
184			if (addr == (void *)-1)
185			addr = 0;
186			#endif
187
188			return addr;
189			}
190
191			static void
192			u_munmap (void *addr, unsigned int len)
193			{
194			#ifdef _WIN32
195			UnmapViewOfFile (addr);
196			#else
197			munmap (addr, len);
198			#endif
199			}
200	root	1.2
201			/////////////////////////////////////////////////////////////////////////////
202
203	root	1.3	typedef struct
204			{
205			char *addr;
206			unsigned int used;
207			unsigned int size;
208			} u_dynbuf;
209
210			static void *
211			u_dynbuf_append (u_dynbuf dynbuf, void data, unsigned int len)
212			{
213			char *dest;
214
215			if ((dynbuf->used += len) > dynbuf->size)
216			{
217			unsigned int new_size = dynbuf->size ? dynbuf->size * 2 : 4096;
218			dynbuf->addr = u_realloc (dynbuf->addr, dynbuf->size, new_size);
219			dynbuf->size = new_size;
220			}
221
222			dest = dynbuf->addr + dynbuf->used - len;
223
224			if (data)
225			memcpy (dest, data, len);
226
227			return dest;
228			}
229
230			/////////////////////////////////////////////////////////////////////////////
231
232	root	1.2	static void
233			u_set_datadir (void)
234			{
235			#ifdef _WIN32
236			if (SHGetFolderPath (0, CSIDL_APPDATA \| CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
237			u_fatal ("unable to find application data directory");
238
239			u_mkdir (datadir);
240			u_append (datadir, URLADER);
241
242			#else
243			char *home = getenv ("HOME");
244
245			if (!home)
246			{
247			struct passwd *pw;
248
249			if ((pw = getpwuid (getuid ())))
250			home = pw->pw_dir;
251			else
252			home = "/tmp";
253			}
254
255			u_mkdir (home);
256			//strcat (strcat (strcpy (datadir, home), "/."), URLADER);
257			sprintf (datadir, "%s/.%s", home, URLADER);
258			#endif
259
260			u_setenv ("URLADER_DATADIR", datadir);
261			}
262
263			static void
264			u_set_exe_info (void)
265			{
266			strcpy (exe_dir, datadir);
267			u_append (exe_dir, exe_id);
268			u_mkdir (exe_dir);
269
270			strcpy (execdir, exe_dir);
271			u_append (execdir, "i-");
272			strcat (execdir, exe_ver);
273
274			u_setenv ("URLADER_EXECDIR", execdir);
275			u_setenv ("URLADER_EXE_ID" , exe_id);
276			u_setenv ("URLADER_EXE_DIR", exe_dir);
277			u_setenv ("URLADER_EXE_VER", exe_ver);
278			}
279
280			/////////////////////////////////////////////////////////////////////////////
281
282	root	1.1	static u_handle
283			u_lock (const char *path, int excl, int dowait)
284			{
285			u_handle h;
286
287			h = u_lockfile (path);
288			if (!u_valid (h))
289			return h;
290
291			u_cloexec (h);
292
293			for (;;)
294			{
295			int success;
296
297			// acquire the lock
298			#ifdef _WIN32
299			OVERLAPPED ov = { 0 };
300
301			success = LockFileEx (h,
302			(excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
303			\| (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
304			0,
305			1, 0,
306			&ov);
307			#else
308			struct flock lck = { 0 };
309
310			lck.l_type = excl ? F_WRLCK : F_RDLCK;
311			lck.l_whence = SEEK_SET;
312			lck.l_len = 1;
313
314			success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
315			#endif
316
317			if (!success)
318			break;
319
320			// we have the lock, now verify that the lockfile still exists
321
322			#ifdef _WIN32
323			// apparently, we have to open the file to get its info :(
324	root	1.2	{
325			BY_HANDLE_FILE_INFORMATION s1, s2;
326			u_handle h2 = u_lockfile (path);
327			if (!u_valid (h))
328			break;
329
330			success = GetFileInformationByHandle (h, &s1)
331			&& GetFileInformationByHandle (h2, &s2);
332
333			u_close (h2);
334
335			if (!success)
336			break;
337
338			success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
339			&& s1.nFileIndexHigh == s2.nFileIndexHigh
340			&& s1.nFileIndexLow == s2.nFileIndexLow;
341			}
342	root	1.1	#else
343			struct stat s1, s2;
344
345			if (fstat (h, &s1) \|\| stat (path, &s2))
346			break;
347
348			success = s1.st_dev == s2.st_dev
349			&& s1.st_ino == s2.st_ino;
350			#endif
351
352			if (success)
353			return h; // lock successfully acquired
354
355			// files differ, close and retry - should be very rare
356			u_close (h);
357			}
358
359			// failure
360			u_close (h);
361			return u_invalid_handle;
362			}
363