xref: /pciutils/lib/init.c (revision fafca2cb) 
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 };
162 
163 // If PCI_ACCESS_AUTO is selected, we probe the access methods in this order
164 static int probe_sequence[] = {
165   // System-specific methods
166   PCI_ACCESS_SYS_BUS_PCI,
167   PCI_ACCESS_PROC_BUS_PCI,
168   PCI_ACCESS_FBSD_DEVICE,
169   PCI_ACCESS_AIX_DEVICE,
170   PCI_ACCESS_NBSD_LIBPCI,
171   PCI_ACCESS_OBSD_DEVICE,
172   PCI_ACCESS_DARWIN,
173   PCI_ACCESS_SYLIXOS_DEVICE,
174   PCI_ACCESS_HURD,
175   PCI_ACCESS_WIN32_CFGMGR32,
176   PCI_ACCESS_WIN32_KLDBG,
177   PCI_ACCESS_WIN32_SYSDBG,
178   // Low-level methods poking the hardware directly
179   PCI_ACCESS_ECAM,
180   PCI_ACCESS_I386_TYPE1,
181   PCI_ACCESS_I386_TYPE2,
182   PCI_ACCESS_MMIO_TYPE1_EXT,
183   PCI_ACCESS_MMIO_TYPE1,
184   -1,
185 };
186 
187 static void PCI_NONRET
188 pci_generic_error(char *msg, ...)
189 {
190   va_list args;
191 
192   va_start(args, msg);
193   fputs("pcilib: ", stderr);
194   vfprintf(stderr, msg, args);
195   va_end(args);
196   fputc('\n', stderr);
197   exit(1);
198 }
199 
200 static void
201 pci_generic_warn(char *msg, ...)
202 {
203   va_list args;
204 
205   va_start(args, msg);
206   fputs("pcilib: ", stderr);
207   vfprintf(stderr, msg, args);
208   va_end(args);
209   fputc('\n', stderr);
210 }
211 
212 static void
213 pci_generic_debug(char *msg, ...)
214 {
215   va_list args;
216 
217   va_start(args, msg);
218   vfprintf(stdout, msg, args);
219   va_end(args);
220 }
221 
222 static void
223 pci_null_debug(char *msg UNUSED, ...)
224 {
225 }
226 
227 // Memory allocation functions are safe to call if pci_access is not fully initalized or even NULL
228 
229 void *
230 pci_malloc(struct pci_access *a, int size)
231 {
232   void *x = malloc(size);
233 
234   if (!x)
235     (a && a->error ? a->error : pci_generic_error)("Out of memory (allocation of %d bytes failed)", size);
236   return x;
237 }
238 
239 void
240 pci_mfree(void *x)
241 {
242   if (x)
243     free(x);
244 }
245 
246 char *
247 pci_strdup(struct pci_access *a, const char *s)
248 {
249   int len = strlen(s) + 1;
250   char *t = pci_malloc(a, len);
251   memcpy(t, s, len);
252   return t;
253 }
254 
255 int
256 pci_lookup_method(char *name)
257 {
258   int i;
259 
260   for (i=0; i<PCI_ACCESS_MAX; i++)
261     if (pci_methods[i] && !strcmp(pci_methods[i]->name, name))
262       return i;
263   return -1;
264 }
265 
266 char *
267 pci_get_method_name(int index)
268 {
269   if (index < 0 || index >= PCI_ACCESS_MAX)
270     return NULL;
271   else if (!pci_methods[index])
272     return "";
273   else
274     return pci_methods[index]->name;
275 }
276 
277 #if defined(PCI_OS_WINDOWS) || defined(PCI_OS_DJGPP)
278 
279 static void
280 pci_init_name_list_path(struct pci_access *a)
281 {
282   if ((PCI_PATH_IDS_DIR)[0])
283     pci_set_name_list_path(a, PCI_PATH_IDS_DIR "\\" PCI_IDS, 0);
284   else
285     {
286       char *path, *sep;
287       size_t len;
288 
289 #if defined(PCI_OS_WINDOWS) && (defined(_WIN32) || defined(_WINDLL) || defined(_WINDOWS))
290 
291       HMODULE module;
292       size_t size;
293 
294 #if defined(_WIN32)
295       module = (HINSTANCE)&__ImageBase;
296 #elif defined(_WINDLL)
297       module = _hModule;
298 #elif defined(_WINDOWS)
299       module = _hInstance;
300 #endif
301 
302       /*
303        * Module file name can have arbitrary length despite all MS examples say
304        * about MAX_PATH upper limit. This limit does not apply for example when
305        * executable is running from network disk with very long UNC paths or
306        * when using "\\??\\" prefix for specifying executable binary path.
307        * Function GetModuleFileName() returns passed size argument when passed
308        * buffer is too small and does not signal any error. In this case retry
309        * again with larger buffer.
310        */
311       size = 256; /* initial buffer size (more than sizeof(PCI_IDS)-4) */
312 retry:
313       path = pci_malloc(a, size);
314       len = GetModuleFileName(module, path, size-sizeof(PCI_IDS)-4); /* 4 for "\\\\?\\" */
315       if (len >= size-sizeof(PCI_IDS)-4)
316         {
317           free(path);
318           size *= 2;
319           goto retry;
320         }
321       else if (len == 0)
322         path[0] = '\0';
323 
324       /*
325        * GetModuleFileName() has bugs. On Windows 10 it prepends current drive
326        * letter if path is just pure NT namespace (with "\\??\\" prefix). Such
327        * extra drive letter makes path fully invalid and unusable. So remove
328        * extra drive letter to make path valid again.
329        * Reproduce: CreateProcessW("\\??\\C:\\lspci.exe", ...)
330        */
331       if (((path[0] >= 'a' && path[0] <= 'z') ||
332            (path[0] >= 'A' && path[0] <= 'Z')) &&
333           strncmp(path+1, ":\\??\\", 5) == 0)
334         {
335           memmove(path, path+2, len-2);
336           len -= 2;
337           path[len] = '\0';
338         }
339 
340       /*
341        * GetModuleFileName() has bugs. On Windows 10 it does not add "\\\\?\\"
342        * prefix when path is in native NT UNC namespace. Such path is treated by
343        * WinAPI/DOS functions as standard DOS path relative to the current
344        * directory, hence something completely different. So prepend missing
345        * "\\\\?\\" prefix to make path valid again.
346        * Reproduce: CreateProcessW("\\??\\UNC\\10.0.2.4\\qemu\\lspci.exe", ...)
347        *
348        * If path starts with DOS drive letter and with appended PCI_IDS is
349        * longer than 260 bytes and is without "\\\\?\\" prefix then append it.
350        * This prefix is required for paths and file names with DOS drive letter
351        * longer than 260 bytes.
352        */
353       if (strncmp(path, "\\UNC\\", 5) == 0 ||
354           strncmp(path, "UNC\\", 4) == 0 ||
355           (((path[0] >= 'a' && path[0] <= 'z') || (path[0] >= 'A' && path[0] <= 'Z')) &&
356            len + sizeof(PCI_IDS) >= 260))
357         {
358           memmove(path+4, path, len);
359           memcpy(path, "\\\\?\\", 4);
360           len += 4;
361           path[len] = '\0';
362         }
363 
364 #elif defined(PCI_OS_DJGPP) || defined(PCI_OS_WINDOWS)
365 
366       const char *exe_path;
367 
368 #ifdef PCI_OS_DJGPP
369       exe_path = __dos_argv0;
370 #else
371       exe_path = _pgmptr;
372 #endif
373 
374       len = strlen(exe_path);
375       path = pci_malloc(a, len+sizeof(PCI_IDS));
376       memcpy(path, exe_path, len+1);
377 
378 #endif
379 
380       sep = strrchr(path, '\\');
381       if (!sep)
382         {
383           /*
384            * If current module path (current executable for static builds or
385            * current DLL library for shared build) cannot be determined then
386            * fallback to the current directory.
387            */
388           free(path);
389           pci_set_name_list_path(a, PCI_IDS, 0);
390         }
391       else
392         {
393           memcpy(sep+1, PCI_IDS, sizeof(PCI_IDS));
394           pci_set_name_list_path(a, path, 1);
395         }
396     }
397 }
398 
399 #else
400 
401 static void
402 pci_init_name_list_path(struct pci_access *a)
403 {
404   pci_set_name_list_path(a, PCI_PATH_IDS_DIR "/" PCI_IDS, 0);
405 }
406 
407 #endif
408 
409 #ifdef PCI_USE_DNS
410 
411 static void
412 pci_init_dns(struct pci_access *a)
413 {
414   pci_define_param(a, "net.domain", PCI_ID_DOMAIN, "DNS domain used for resolving of ID's");
415   a->id_lookup_mode = PCI_LOOKUP_CACHE;
416 
417   char *cache_dir = getenv("XDG_CACHE_HOME");
418   if (!cache_dir)
419     cache_dir = "~/.cache";
420 
421   int name_len = strlen(cache_dir) + 32;
422   char *cache_name = pci_malloc(NULL, name_len);
423   snprintf(cache_name, name_len, "%s/pci-ids", cache_dir);
424   struct pci_param *param = pci_define_param(a, "net.cache_name", cache_name, "Name of the ID cache file");
425   param->value_malloced = 1;
426 }
427 
428 #endif
429 
430 struct pci_access *
431 pci_alloc(void)
432 {
433   struct pci_access *a = pci_malloc(NULL, sizeof(struct pci_access));
434   int i;
435 
436   memset(a, 0, sizeof(*a));
437   pci_init_name_list_path(a);
438 #ifdef PCI_USE_DNS
439   pci_init_dns(a);
440 #endif
441 #ifdef PCI_HAVE_HWDB
442   pci_define_param(a, "hwdb.disable", "0", "Do not look up names in UDEV's HWDB if non-zero");
443 #endif
444   for (i=0; i<PCI_ACCESS_MAX; i++)
445     if (pci_methods[i] && pci_methods[i]->config)
446       pci_methods[i]->config(a);
447   return a;
448 }
449 
450 int
451 pci_init_internal(struct pci_access *a, int skip_method)
452 {
453   if (!a->error)
454     a->error = pci_generic_error;
455   if (!a->warning)
456     a->warning = pci_generic_warn;
457   if (!a->debug)
458     a->debug = pci_generic_debug;
459   if (!a->debugging)
460     a->debug = pci_null_debug;
461 
462   if (a->method != PCI_ACCESS_AUTO)
463     {
464       if (a->method >= PCI_ACCESS_MAX || !pci_methods[a->method])
465 	a->error("This access method is not supported.");
466       a->methods = pci_methods[a->method];
467     }
468   else
469     {
470       unsigned int i;
471       for (i=0; probe_sequence[i] >= 0; i++)
472 	{
473 	  struct pci_methods *m = pci_methods[probe_sequence[i]];
474 	  if (!m)
475 	    continue;
476 	  if (skip_method == probe_sequence[i])
477 	    continue;
478 	  a->debug("Trying method %s...", m->name);
479 	  if (m->detect(a))
480 	    {
481 	      a->debug("...OK\n");
482 	      a->methods = m;
483 	      a->method = probe_sequence[i];
484 	      break;
485 	    }
486 	  a->debug("...No.\n");
487 	}
488       if (!a->methods)
489 	return 0;
490     }
491   a->debug("Decided to use %s\n", a->methods->name);
492   a->methods->init(a);
493   return 1;
494 }
495 
496 void
497 pci_init_v35(struct pci_access *a)
498 {
499   if (!pci_init_internal(a, -1))
500     a->error("Cannot find any working access method.");
501 }
502 
503 STATIC_ALIAS(void pci_init(struct pci_access *a), pci_init_v35(a));
504 DEFINE_ALIAS(void pci_init_v30(struct pci_access *a), pci_init_v35);
505 SYMBOL_VERSION(pci_init_v30, pci_init@LIBPCI_3.0);
506 SYMBOL_VERSION(pci_init_v35, pci_init@@LIBPCI_3.5);
507 
508 struct pci_access *
509 pci_clone_access(struct pci_access *a)
510 {
511   struct pci_access *b = pci_alloc();
512 
513   b->writeable = a->writeable;
514   b->buscentric = a->buscentric;
515   b->debugging = a->debugging;
516   b->error = a->error;
517   b->warning = a->warning;
518   b->debug = a->debug;
519 
520   return b;
521 }
522 
523 void
524 pci_cleanup(struct pci_access *a)
525 {
526   struct pci_dev *d, *e;
527 
528   for (d=a->devices; d; d=e)
529     {
530       e = d->next;
531       pci_free_dev(d);
532     }
533   if (a->methods)
534     a->methods->cleanup(a);
535   pci_free_name_list(a);
536   pci_free_params(a);
537   pci_set_name_list_path(a, NULL, 0);
538   pci_mfree(a);
539 }
540