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/cvs/Urlader/urlib.c
Revision: 1.3
Committed: Fri Jan 6 07:56:36 2012 UTC (12 years, 9 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.2: +54 -6 lines
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File Contents

# 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