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 *
#	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	if (!size)
116	return 0;
117
118	#ifdef _WIN32
119	HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);
120
121	addr = 0;
122	if (handle)
123	{
124	addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);
125	CloseHandle (handle);
126	}
127	#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	if (!addr)
137	u_fatal ("memory allocation failure, aborting.");
138
139	return addr;
140	}
141
142	static void
143	u_free (void *addr, unsigned int size)
144	{
145	if (!addr)
146	return;
147
148	#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	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	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
201	/////////////////////////////////////////////////////////////////////////////
202
203	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	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	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	{
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	#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