xref: /pciutils/lib/init.c (revision 42fc4263) 
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 };
167 
168 // If PCI_ACCESS_AUTO is selected, we probe the access methods in this order
169 static int probe_sequence[] = {
170   // System-specific methods
171   PCI_ACCESS_SYS_BUS_PCI,
172   PCI_ACCESS_PROC_BUS_PCI,
173   PCI_ACCESS_FBSD_DEVICE,
174   PCI_ACCESS_AIX_DEVICE,
175   PCI_ACCESS_NBSD_LIBPCI,
176   PCI_ACCESS_OBSD_DEVICE,
177   PCI_ACCESS_DARWIN,
178   PCI_ACCESS_SYLIXOS_DEVICE,
179   PCI_ACCESS_HURD,
180   PCI_ACCESS_WIN32_CFGMGR32,
181   PCI_ACCESS_WIN32_KLDBG,
182   PCI_ACCESS_WIN32_SYSDBG,
183   PCI_ACCESS_AOS_EXPANSION,
184   // Low-level methods poking the hardware directly
185   PCI_ACCESS_ECAM,
186   PCI_ACCESS_I386_TYPE1,
187   PCI_ACCESS_I386_TYPE2,
188   PCI_ACCESS_MMIO_TYPE1_EXT,
189   PCI_ACCESS_MMIO_TYPE1,
190   -1,
191 };
192 
193 static void PCI_NONRET
194 pci_generic_error(char *msg, ...)
195 {
196   va_list args;
197 
198   va_start(args, msg);
199   fputs("pcilib: ", stderr);
200   vfprintf(stderr, msg, args);
201   va_end(args);
202   fputc('\n', stderr);
203   exit(1);
204 }
205 
206 static void
207 pci_generic_warn(char *msg, ...)
208 {
209   va_list args;
210 
211   va_start(args, msg);
212   fputs("pcilib: ", stderr);
213   vfprintf(stderr, msg, args);
214   va_end(args);
215   fputc('\n', stderr);
216 }
217 
218 static void
219 pci_generic_debug(char *msg, ...)
220 {
221   va_list args;
222 
223   va_start(args, msg);
224   vfprintf(stdout, msg, args);
225   va_end(args);
226 }
227 
228 static void
229 pci_null_debug(char *msg UNUSED, ...)
230 {
231 }
232 
233 // Memory allocation functions are safe to call if pci_access is not fully initalized or even NULL
234 
235 void *
236 pci_malloc(struct pci_access *a, int size)
237 {
238   void *x = malloc(size);
239 
240   if (!x)
241     (a && a->error ? a->error : pci_generic_error)("Out of memory (allocation of %d bytes failed)", size);
242   return x;
243 }
244 
245 void
246 pci_mfree(void *x)
247 {
248   if (x)
249     free(x);
250 }
251 
252 char *
253 pci_strdup(struct pci_access *a, const char *s)
254 {
255   int len = strlen(s) + 1;
256   char *t = pci_malloc(a, len);
257   memcpy(t, s, len);
258   return t;
259 }
260 
261 int
262 pci_lookup_method(char *name)
263 {
264   int i;
265 
266   for (i=0; i<PCI_ACCESS_MAX; i++)
267     if (pci_methods[i] && !strcmp(pci_methods[i]->name, name))
268       return i;
269   return -1;
270 }
271 
272 char *
273 pci_get_method_name(int index)
274 {
275   if (index < 0 || index >= PCI_ACCESS_MAX)
276     return NULL;
277   else if (!pci_methods[index])
278     return "";
279   else
280     return pci_methods[index]->name;
281 }
282 
283 #if defined(PCI_OS_WINDOWS) || defined(PCI_OS_DJGPP)
284 
285 static void
286 pci_init_name_list_path(struct pci_access *a)
287 {
288   if ((PCI_PATH_IDS_DIR)[0])
289     pci_set_name_list_path(a, PCI_PATH_IDS_DIR "\\" PCI_IDS, 0);
290   else
291     {
292       char *path, *sep;
293       size_t len;
294 
295 #if defined(PCI_OS_WINDOWS) && (defined(_WIN32) || defined(_WINDLL) || defined(_WINDOWS))
296 
297       HMODULE module;
298       size_t size;
299 
300 #if defined(_WIN32)
301       module = (HINSTANCE)&__ImageBase;
302 #elif defined(_WINDLL)
303       module = _hModule;
304 #elif defined(_WINDOWS)
305       module = _hInstance;
306 #endif
307 
308       /*
309        * Module file name can have arbitrary length despite all MS examples say
310        * about MAX_PATH upper limit. This limit does not apply for example when
311        * executable is running from network disk with very long UNC paths or
312        * when using "\\??\\" prefix for specifying executable binary path.
313        * Function GetModuleFileName() returns passed size argument when passed
314        * buffer is too small and does not signal any error. In this case retry
315        * again with larger buffer.
316        */
317       size = 256; /* initial buffer size (more than sizeof(PCI_IDS)-4) */
318 retry:
319       path = pci_malloc(a, size);
320       len = GetModuleFileName(module, path, size-sizeof(PCI_IDS)-4); /* 4 for "\\\\?\\" */
321       if (len >= size-sizeof(PCI_IDS)-4)
322         {
323           free(path);
324           size *= 2;
325           goto retry;
326         }
327       else if (len == 0)
328         path[0] = '\0';
329 
330       /*
331        * GetModuleFileName() has bugs. On Windows 10 it prepends current drive
332        * letter if path is just pure NT namespace (with "\\??\\" prefix). Such
333        * extra drive letter makes path fully invalid and unusable. So remove
334        * extra drive letter to make path valid again.
335        * Reproduce: CreateProcessW("\\??\\C:\\lspci.exe", ...)
336        */
337       if (((path[0] >= 'a' && path[0] <= 'z') ||
338            (path[0] >= 'A' && path[0] <= 'Z')) &&
339           strncmp(path+1, ":\\??\\", 5) == 0)
340         {
341           memmove(path, path+2, len-2);
342           len -= 2;
343           path[len] = '\0';
344         }
345 
346       /*
347        * GetModuleFileName() has bugs. On Windows 10 it does not add "\\\\?\\"
348        * prefix when path is in native NT UNC namespace. Such path is treated by
349        * WinAPI/DOS functions as standard DOS path relative to the current
350        * directory, hence something completely different. So prepend missing
351        * "\\\\?\\" prefix to make path valid again.
352        * Reproduce: CreateProcessW("\\??\\UNC\\10.0.2.4\\qemu\\lspci.exe", ...)
353        *
354        * If path starts with DOS drive letter and with appended PCI_IDS is
355        * longer than 260 bytes and is without "\\\\?\\" prefix then append it.
356        * This prefix is required for paths and file names with DOS drive letter
357        * longer than 260 bytes.
358        */
359       if (strncmp(path, "\\UNC\\", 5) == 0 ||
360           strncmp(path, "UNC\\", 4) == 0 ||
361           (((path[0] >= 'a' && path[0] <= 'z') || (path[0] >= 'A' && path[0] <= 'Z')) &&
362            len + sizeof(PCI_IDS) >= 260))
363         {
364           memmove(path+4, path, len);
365           memcpy(path, "\\\\?\\", 4);
366           len += 4;
367           path[len] = '\0';
368         }
369 
370 #elif defined(PCI_OS_DJGPP) || defined(PCI_OS_WINDOWS)
371 
372       const char *exe_path;
373 
374 #ifdef PCI_OS_DJGPP
375       exe_path = __dos_argv0;
376 #else
377       exe_path = _pgmptr;
378 #endif
379 
380       len = strlen(exe_path);
381       path = pci_malloc(a, len+sizeof(PCI_IDS));
382       memcpy(path, exe_path, len+1);
383 
384 #endif
385 
386       sep = strrchr(path, '\\');
387       if (!sep)
388         {
389           /*
390            * If current module path (current executable for static builds or
391            * current DLL library for shared build) cannot be determined then
392            * fallback to the current directory.
393            */
394           free(path);
395           pci_set_name_list_path(a, PCI_IDS, 0);
396         }
397       else
398         {
399           memcpy(sep+1, PCI_IDS, sizeof(PCI_IDS));
400           pci_set_name_list_path(a, path, 1);
401         }
402     }
403 }
404 
405 #elif defined PCI_OS_AMIGAOS
406 
407 static void
408 pci_init_name_list_path(struct pci_access *a)
409 {
410   int len = strlen(PCI_PATH_IDS_DIR);
411 
412   if (!len)
413     pci_set_name_list_path(a, PCI_IDS, 0);
414   else
415     {
416       char last_char = PCI_PATH_IDS_DIR[len - 1];
417       if (last_char == ':' || last_char == '/')  // root or parent char
418 	pci_set_name_list_path(a, PCI_PATH_IDS_DIR PCI_IDS, 0);
419       else
420 	pci_set_name_list_path(a, PCI_PATH_IDS_DIR "/" PCI_IDS, 0);
421     }
422 }
423 
424 #else
425 
426 static void
427 pci_init_name_list_path(struct pci_access *a)
428 {
429   pci_set_name_list_path(a, PCI_PATH_IDS_DIR "/" PCI_IDS, 0);
430 }
431 
432 #endif
433 
434 #ifdef PCI_USE_DNS
435 
436 static void
437 pci_init_dns(struct pci_access *a)
438 {
439   pci_define_param(a, "net.domain", PCI_ID_DOMAIN, "DNS domain used for resolving of ID's");
440   a->id_lookup_mode = PCI_LOOKUP_CACHE;
441 
442   char *cache_dir = getenv("XDG_CACHE_HOME");
443   if (!cache_dir)
444     cache_dir = "~/.cache";
445 
446   int name_len = strlen(cache_dir) + 32;
447   char *cache_name = pci_malloc(NULL, name_len);
448   snprintf(cache_name, name_len, "%s/pci-ids", cache_dir);
449   struct pci_param *param = pci_define_param(a, "net.cache_name", cache_name, "Name of the ID cache file");
450   param->value_malloced = 1;
451 }
452 
453 #endif
454 
455 struct pci_access *
456 pci_alloc(void)
457 {
458   struct pci_access *a = pci_malloc(NULL, sizeof(struct pci_access));
459   int i;
460 
461   memset(a, 0, sizeof(*a));
462   pci_init_name_list_path(a);
463 #ifdef PCI_USE_DNS
464   pci_init_dns(a);
465 #endif
466 #ifdef PCI_HAVE_HWDB
467   pci_define_param(a, "hwdb.disable", "0", "Do not look up names in UDEV's HWDB if non-zero");
468 #endif
469   for (i=0; i<PCI_ACCESS_MAX; i++)
470     if (pci_methods[i] && pci_methods[i]->config)
471       pci_methods[i]->config(a);
472   return a;
473 }
474 
475 int
476 pci_init_internal(struct pci_access *a, int skip_method)
477 {
478   if (!a->error)
479     a->error = pci_generic_error;
480   if (!a->warning)
481     a->warning = pci_generic_warn;
482   if (!a->debug)
483     a->debug = pci_generic_debug;
484   if (!a->debugging)
485     a->debug = pci_null_debug;
486 
487   if (a->method != PCI_ACCESS_AUTO)
488     {
489       if (a->method >= PCI_ACCESS_MAX || !pci_methods[a->method])
490 	a->error("This access method is not supported.");
491       a->methods = pci_methods[a->method];
492     }
493   else
494     {
495       unsigned int i;
496       for (i=0; probe_sequence[i] >= 0; i++)
497 	{
498 	  struct pci_methods *m = pci_methods[probe_sequence[i]];
499 	  if (!m)
500 	    continue;
501 	  if (skip_method == probe_sequence[i])
502 	    continue;
503 	  a->debug("Trying method %s...", m->name);
504 	  if (m->detect(a))
505 	    {
506 	      a->debug("...OK\n");
507 	      a->methods = m;
508 	      a->method = probe_sequence[i];
509 	      break;
510 	    }
511 	  a->debug("...No.\n");
512 	}
513       if (!a->methods)
514 	return 0;
515     }
516   a->debug("Decided to use %s\n", a->methods->name);
517   a->methods->init(a);
518   return 1;
519 }
520 
521 void
522 pci_init_v35(struct pci_access *a)
523 {
524   if (!pci_init_internal(a, -1))
525     a->error("Cannot find any working access method.");
526 }
527 
528 STATIC_ALIAS(void pci_init(struct pci_access *a), pci_init_v35(a));
529 DEFINE_ALIAS(void pci_init_v30(struct pci_access *a), pci_init_v35);
530 SYMBOL_VERSION(pci_init_v30, pci_init@LIBPCI_3.0);
531 SYMBOL_VERSION(pci_init_v35, pci_init@@LIBPCI_3.5);
532 
533 struct pci_access *
534 pci_clone_access(struct pci_access *a)
535 {
536   struct pci_access *b = pci_alloc();
537 
538   b->writeable = a->writeable;
539   b->buscentric = a->buscentric;
540   b->debugging = a->debugging;
541   b->error = a->error;
542   b->warning = a->warning;
543   b->debug = a->debug;
544 
545   return b;
546 }
547 
548 void
549 pci_cleanup(struct pci_access *a)
550 {
551   struct pci_dev *d, *e;
552 
553   for (d=a->devices; d; d=e)
554     {
555       e = d->next;
556       pci_free_dev(d);
557     }
558   if (a->methods)
559     a->methods->cleanup(a);
560   pci_free_name_list(a);
561   pci_free_params(a);
562   pci_set_name_list_path(a, NULL, 0);
563   pci_mfree(a);
564 }
565