xref: /pciutils/lib/init.c (revision 9611db3e) 
1 /*
2  *	The PCI Library -- Initialization and related things
3  *
4  *	Copyright (c) 1997--2024 Martin Mares <[email protected]>
5  *
6  *	Can be freely distributed and used under the terms of the GNU GPL v2+.
7  *
8  *	SPDX-License-Identifier: GPL-2.0-or-later
9  */
10 
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <stdarg.h>
14 #include <string.h>
15 
16 #include "internal.h"
17 
18 #ifdef PCI_OS_DJGPP
19 #include <crt0.h> /* for __dos_argv0 */
20 #endif
21 
22 #ifdef PCI_OS_WINDOWS
23 
24 #include <windows.h>
25 
26 /* Force usage of ANSI (char*) variant of GetModuleFileName() function */
27 #ifdef _WIN32
28 #ifdef GetModuleFileName
29 #undef GetModuleFileName
30 #endif
31 #define GetModuleFileName GetModuleFileNameA
32 #endif
33 
34 /* Define __ImageBase for all linkers */
35 #ifdef _WIN32
36 /* GNU LD provides __ImageBase symbol since 2.19, in previous versions it is
37  * under name _image_base__, so add weak alias for compatibility. */
38 #ifdef __GNUC__
39 asm(".weak\t" PCI_STRINGIFY(__MINGW_USYMBOL(__ImageBase)) "\n\t"
40     ".set\t"  PCI_STRINGIFY(__MINGW_USYMBOL(__ImageBase)) "," PCI_STRINGIFY(__MINGW_USYMBOL(_image_base__)));
41 #endif
42 /*
43  * MSVC link.exe provides __ImageBase symbol since 12.00 (MSVC 6.0), for
44  * previous versions resolve it at runtime via GetModuleHandleA() which
45  * returns base for main executable or via VirtualQuery() for DLL builds.
46  */
47 #if defined(_MSC_VER) && _MSC_VER < 1200
48 static HMODULE
49 get_current_module_handle(void)
50 {
51 #ifdef PCI_SHARED_LIB
52   MEMORY_BASIC_INFORMATION info;
53   size_t len = VirtualQuery(&get_current_module_handle, &info, sizeof(info));
54   if (len != sizeof(info))
55     return NULL;
56   return (HMODULE)info.AllocationBase;
57 #else
58   return GetModuleHandleA(NULL);
59 #endif
60 }
61 #define __ImageBase (*(IMAGE_DOS_HEADER *)get_current_module_handle())
62 #else
63 extern IMAGE_DOS_HEADER __ImageBase;
64 #endif
65 #endif
66 
67 #if defined(_WINDLL)
68 extern HINSTANCE _hModule;
69 #elif defined(_WINDOWS)
70 extern HINSTANCE _hInstance;
71 #endif
72 
73 #endif
74 
75 static struct pci_methods *pci_methods[PCI_ACCESS_MAX] = {
76   NULL,
77 #ifdef PCI_HAVE_PM_LINUX_SYSFS
78   &pm_linux_sysfs,
79 #else
80   NULL,
81 #endif
82 #ifdef PCI_HAVE_PM_LINUX_PROC
83   &pm_linux_proc,
84 #else
85   NULL,
86 #endif
87 #ifdef PCI_HAVE_PM_INTEL_CONF
88   &pm_intel_conf1,
89   &pm_intel_conf2,
90 #else
91   NULL,
92   NULL,
93 #endif
94 #ifdef PCI_HAVE_PM_FBSD_DEVICE
95   &pm_fbsd_device,
96 #else
97   NULL,
98 #endif
99 #ifdef PCI_HAVE_PM_AIX_DEVICE
100   &pm_aix_device,
101 #else
102   NULL,
103 #endif
104 #ifdef PCI_HAVE_PM_NBSD_LIBPCI
105   &pm_nbsd_libpci,
106 #else
107   NULL,
108 #endif
109 #ifdef PCI_HAVE_PM_OBSD_DEVICE
110   &pm_obsd_device,
111 #else
112   NULL,
113 #endif
114 #ifdef PCI_HAVE_PM_DUMP
115   &pm_dump,
116 #else
117   NULL,
118 #endif
119 #ifdef PCI_HAVE_PM_DARWIN_DEVICE
120   &pm_darwin,
121 #else
122   NULL,
123 #endif
124 #ifdef PCI_HAVE_PM_SYLIXOS_DEVICE
125   &pm_sylixos_device,
126 #else
127   NULL,
128 #endif
129 #ifdef PCI_HAVE_PM_HURD_CONF
130   &pm_hurd,
131 #else
132   NULL,
133 #endif
134 #ifdef PCI_HAVE_PM_WIN32_CFGMGR32
135   &pm_win32_cfgmgr32,
136 #else
137   NULL,
138 #endif
139 #ifdef PCI_HAVE_PM_WIN32_KLDBG
140   &pm_win32_kldbg,
141 #else
142   NULL,
143 #endif
144 #ifdef PCI_HAVE_PM_WIN32_SYSDBG
145   &pm_win32_sysdbg,
146 #else
147   NULL,
148 #endif
149 #ifdef PCI_HAVE_PM_MMIO_CONF
150   &pm_mmio_conf1,
151   &pm_mmio_conf1_ext,
152 #else
153   NULL,
154   NULL,
155 #endif
156 #if defined(PCI_HAVE_PM_ECAM)
157   &pm_ecam,
158 #else
159   NULL,
160 #endif
161 #if defined(PCI_HAVE_PM_AOS_EXPANSION)
162   &pm_aos_expansion,
163 #else
164   NULL,
165 #endif
166 #ifdef PCI_HAVE_PM_RT_THREAD_SMART_DM
167   &pm_rt_thread_smart_dm,
168 #else
169   NULL,
170 #endif
171 };
172 
173 // If PCI_ACCESS_AUTO is selected, we probe the access methods in this order
174 static int probe_sequence[] = {
175   // System-specific methods
176   PCI_ACCESS_SYS_BUS_PCI,
177   PCI_ACCESS_PROC_BUS_PCI,
178   PCI_ACCESS_FBSD_DEVICE,
179   PCI_ACCESS_AIX_DEVICE,
180   PCI_ACCESS_NBSD_LIBPCI,
181   PCI_ACCESS_OBSD_DEVICE,
182   PCI_ACCESS_DARWIN,
183   PCI_ACCESS_SYLIXOS_DEVICE,
184   PCI_ACCESS_HURD,
185   PCI_ACCESS_WIN32_CFGMGR32,
186   PCI_ACCESS_WIN32_KLDBG,
187   PCI_ACCESS_WIN32_SYSDBG,
188   PCI_ACCESS_AOS_EXPANSION,
189   PCI_ACCESS_RT_THREAD_SMART_DM,
190   // Low-level methods poking the hardware directly
191   PCI_ACCESS_ECAM,
192   PCI_ACCESS_I386_TYPE1,
193   PCI_ACCESS_I386_TYPE2,
194   PCI_ACCESS_MMIO_TYPE1_EXT,
195   PCI_ACCESS_MMIO_TYPE1,
196   -1,
197 };
198 
199 static void PCI_NONRET
200 pci_generic_error(char *msg, ...)
201 {
202   va_list args;
203 
204   va_start(args, msg);
205   fputs("pcilib: ", stderr);
206   vfprintf(stderr, msg, args);
207   va_end(args);
208   fputc('\n', stderr);
209   exit(1);
210 }
211 
212 static void
213 pci_generic_warn(char *msg, ...)
214 {
215   va_list args;
216 
217   va_start(args, msg);
218   fputs("pcilib: ", stderr);
219   vfprintf(stderr, msg, args);
220   va_end(args);
221   fputc('\n', stderr);
222 }
223 
224 static void
225 pci_generic_debug(char *msg, ...)
226 {
227   va_list args;
228 
229   va_start(args, msg);
230   vfprintf(stdout, msg, args);
231   va_end(args);
232 }
233 
234 static void
235 pci_null_debug(char *msg UNUSED, ...)
236 {
237 }
238 
239 // Memory allocation functions are safe to call if pci_access is not fully initalized or even NULL
240 
241 void *
242 pci_malloc(struct pci_access *a, int size)
243 {
244   void *x = malloc(size);
245 
246   if (!x)
247     (a && a->error ? a->error : pci_generic_error)("Out of memory (allocation of %d bytes failed)", size);
248   return x;
249 }
250 
251 void
252 pci_mfree(void *x)
253 {
254   if (x)
255     free(x);
256 }
257 
258 char *
259 pci_strdup(struct pci_access *a, const char *s)
260 {
261   int len = strlen(s) + 1;
262   char *t = pci_malloc(a, len);
263   memcpy(t, s, len);
264   return t;
265 }
266 
267 int
268 pci_lookup_method(char *name)
269 {
270   int i;
271 
272   for (i=0; i<PCI_ACCESS_MAX; i++)
273     if (pci_methods[i] && !strcmp(pci_methods[i]->name, name))
274       return i;
275   return -1;
276 }
277 
278 char *
279 pci_get_method_name(int index)
280 {
281   if (index < 0 || index >= PCI_ACCESS_MAX)
282     return NULL;
283   else if (!pci_methods[index])
284     return "";
285   else
286     return pci_methods[index]->name;
287 }
288 
289 #if defined(PCI_OS_WINDOWS) || defined(PCI_OS_DJGPP)
290 
291 static void
292 pci_init_name_list_path(struct pci_access *a)
293 {
294   if ((PCI_PATH_IDS_DIR)[0])
295     pci_set_name_list_path(a, PCI_PATH_IDS_DIR "\\" PCI_IDS, 0);
296   else
297     {
298       char *path, *sep;
299       size_t len;
300 
301 #if defined(PCI_OS_WINDOWS) && (defined(_WIN32) || defined(_WINDLL) || defined(_WINDOWS))
302 
303       HMODULE module;
304       size_t size;
305 
306 #if defined(_WIN32)
307       module = (HINSTANCE)&__ImageBase;
308 #elif defined(_WINDLL)
309       module = _hModule;
310 #elif defined(_WINDOWS)
311       module = _hInstance;
312 #endif
313 
314       /*
315        * Module file name can have arbitrary length despite all MS examples say
316        * about MAX_PATH upper limit. This limit does not apply for example when
317        * executable is running from network disk with very long UNC paths or
318        * when using "\\??\\" prefix for specifying executable binary path.
319        * Function GetModuleFileName() returns passed size argument when passed
320        * buffer is too small and does not signal any error. In this case retry
321        * again with larger buffer.
322        */
323       size = 256; /* initial buffer size (more than sizeof(PCI_IDS)-4) */
324 retry:
325       path = pci_malloc(a, size);
326       len = GetModuleFileName(module, path, size-sizeof(PCI_IDS)-4); /* 4 for "\\\\?\\" */
327       if (len >= size-sizeof(PCI_IDS)-4)
328         {
329           free(path);
330           size *= 2;
331           goto retry;
332         }
333       else if (len == 0)
334         path[0] = '\0';
335 
336       /*
337        * GetModuleFileName() has bugs. On Windows 10 it prepends current drive
338        * letter if path is just pure NT namespace (with "\\??\\" prefix). Such
339        * extra drive letter makes path fully invalid and unusable. So remove
340        * extra drive letter to make path valid again.
341        * Reproduce: CreateProcessW("\\??\\C:\\lspci.exe", ...)
342        */
343       if (((path[0] >= 'a' && path[0] <= 'z') ||
344            (path[0] >= 'A' && path[0] <= 'Z')) &&
345           strncmp(path+1, ":\\??\\", 5) == 0)
346         {
347           memmove(path, path+2, len-2);
348           len -= 2;
349           path[len] = '\0';
350         }
351 
352       /*
353        * GetModuleFileName() has bugs. On Windows 10 it does not add "\\\\?\\"
354        * prefix when path is in native NT UNC namespace. Such path is treated by
355        * WinAPI/DOS functions as standard DOS path relative to the current
356        * directory, hence something completely different. So prepend missing
357        * "\\\\?\\" prefix to make path valid again.
358        * Reproduce: CreateProcessW("\\??\\UNC\\10.0.2.4\\qemu\\lspci.exe", ...)
359        *
360        * If path starts with DOS drive letter and with appended PCI_IDS is
361        * longer than 260 bytes and is without "\\\\?\\" prefix then append it.
362        * This prefix is required for paths and file names with DOS drive letter
363        * longer than 260 bytes.
364        */
365       if (strncmp(path, "\\UNC\\", 5) == 0 ||
366           strncmp(path, "UNC\\", 4) == 0 ||
367           (((path[0] >= 'a' && path[0] <= 'z') || (path[0] >= 'A' && path[0] <= 'Z')) &&
368            len + sizeof(PCI_IDS) >= 260))
369         {
370           memmove(path+4, path, len);
371           memcpy(path, "\\\\?\\", 4);
372           len += 4;
373           path[len] = '\0';
374         }
375 
376 #elif defined(PCI_OS_DJGPP) || defined(PCI_OS_WINDOWS)
377 
378       const char *exe_path;
379 
380 #ifdef PCI_OS_DJGPP
381       exe_path = __dos_argv0;
382 #else
383       exe_path = _pgmptr;
384 #endif
385 
386       len = strlen(exe_path);
387       path = pci_malloc(a, len+sizeof(PCI_IDS));
388       memcpy(path, exe_path, len+1);
389 
390 #endif
391 
392       sep = strrchr(path, '\\');
393       if (!sep)
394         {
395           /*
396            * If current module path (current executable for static builds or
397            * current DLL library for shared build) cannot be determined then
398            * fallback to the current directory.
399            */
400           free(path);
401           pci_set_name_list_path(a, PCI_IDS, 0);
402         }
403       else
404         {
405           memcpy(sep+1, PCI_IDS, sizeof(PCI_IDS));
406           pci_set_name_list_path(a, path, 1);
407         }
408     }
409 }
410 
411 #elif defined PCI_OS_AMIGAOS
412 
413 static void
414 pci_init_name_list_path(struct pci_access *a)
415 {
416   int len = strlen(PCI_PATH_IDS_DIR);
417 
418   if (!len)
419     pci_set_name_list_path(a, PCI_IDS, 0);
420   else
421     {
422       char last_char = PCI_PATH_IDS_DIR[len - 1];
423       if (last_char == ':' || last_char == '/')  // root or parent char
424 	pci_set_name_list_path(a, PCI_PATH_IDS_DIR PCI_IDS, 0);
425       else
426 	pci_set_name_list_path(a, PCI_PATH_IDS_DIR "/" PCI_IDS, 0);
427     }
428 }
429 
430 #else
431 
432 static void
433 pci_init_name_list_path(struct pci_access *a)
434 {
435   pci_set_name_list_path(a, PCI_PATH_IDS_DIR "/" PCI_IDS, 0);
436 }
437 
438 #endif
439 
440 #ifdef PCI_USE_DNS
441 
442 static void
443 pci_init_dns(struct pci_access *a)
444 {
445   pci_define_param(a, "net.domain", PCI_ID_DOMAIN, "DNS domain used for resolving of ID's");
446   a->id_lookup_mode = PCI_LOOKUP_CACHE;
447 
448   char *cache_dir = getenv("XDG_CACHE_HOME");
449   if (!cache_dir)
450     cache_dir = "~/.cache";
451 
452   int name_len = strlen(cache_dir) + 32;
453   char *cache_name = pci_malloc(NULL, name_len);
454   snprintf(cache_name, name_len, "%s/pci-ids", cache_dir);
455   struct pci_param *param = pci_define_param(a, "net.cache_name", cache_name, "Name of the ID cache file");
456   param->value_malloced = 1;
457 }
458 
459 #endif
460 
461 struct pci_access *
462 pci_alloc(void)
463 {
464   struct pci_access *a = pci_malloc(NULL, sizeof(struct pci_access));
465   int i;
466 
467   memset(a, 0, sizeof(*a));
468   pci_init_name_list_path(a);
469 #ifdef PCI_USE_DNS
470   pci_init_dns(a);
471 #endif
472 #ifdef PCI_HAVE_HWDB
473   pci_define_param(a, "hwdb.disable", "0", "Do not look up names in UDEV's HWDB if non-zero");
474 #endif
475   for (i=0; i<PCI_ACCESS_MAX; i++)
476     if (pci_methods[i] && pci_methods[i]->config)
477       pci_methods[i]->config(a);
478   return a;
479 }
480 
481 int
482 pci_init_internal(struct pci_access *a, int skip_method)
483 {
484   if (!a->error)
485     a->error = pci_generic_error;
486   if (!a->warning)
487     a->warning = pci_generic_warn;
488   if (!a->debug)
489     a->debug = pci_generic_debug;
490   if (!a->debugging)
491     a->debug = pci_null_debug;
492 
493   if (a->method != PCI_ACCESS_AUTO)
494     {
495       if (a->method >= PCI_ACCESS_MAX || !pci_methods[a->method])
496 	a->error("This access method is not supported.");
497       a->methods = pci_methods[a->method];
498     }
499   else
500     {
501       unsigned int i;
502       for (i=0; probe_sequence[i] >= 0; i++)
503 	{
504 	  struct pci_methods *m = pci_methods[probe_sequence[i]];
505 	  if (!m)
506 	    continue;
507 	  if (skip_method == probe_sequence[i])
508 	    continue;
509 	  a->debug("Trying method %s...", m->name);
510 	  if (m->detect(a))
511 	    {
512 	      a->debug("...OK\n");
513 	      a->methods = m;
514 	      a->method = probe_sequence[i];
515 	      break;
516 	    }
517 	  a->debug("...No.\n");
518 	}
519       if (!a->methods)
520 	return 0;
521     }
522   a->debug("Decided to use %s\n", a->methods->name);
523   a->methods->init(a);
524   return 1;
525 }
526 
527 void
528 pci_init_v35(struct pci_access *a)
529 {
530   if (!pci_init_internal(a, -1))
531     a->error("Cannot find any working access method.");
532 }
533 
534 STATIC_ALIAS(void pci_init(struct pci_access *a), pci_init_v35(a));
535 DEFINE_ALIAS(void pci_init_v30(struct pci_access *a), pci_init_v35);
536 SYMBOL_VERSION(pci_init_v30, pci_init@LIBPCI_3.0);
537 SYMBOL_VERSION(pci_init_v35, pci_init@@LIBPCI_3.5);
538 
539 struct pci_access *
540 pci_clone_access(struct pci_access *a)
541 {
542   struct pci_access *b = pci_alloc();
543 
544   b->writeable = a->writeable;
545   b->buscentric = a->buscentric;
546   b->debugging = a->debugging;
547   b->error = a->error;
548   b->warning = a->warning;
549   b->debug = a->debug;
550 
551   return b;
552 }
553 
554 void
555 pci_cleanup(struct pci_access *a)
556 {
557   struct pci_dev *d, *e;
558 
559   for (d=a->devices; d; d=e)
560     {
561       e = d->next;
562       pci_free_dev(d);
563     }
564   if (a->methods)
565     a->methods->cleanup(a);
566   pci_free_name_list(a);
567   pci_free_params(a);
568   pci_set_name_list_path(a, NULL, 0);
569   pci_mfree(a);
570 }
571