1  /* SPDX-License-Identifier: GPL-2.0-or-later */
  2  
  3  #include "utils.h"
  4  
  5  #include <sys/mman.h>
  6  #include <sys/stat.h>
  7  #include <fcntl.h>
  8  #include <unistd.h>
  9  
 10  #include <errno.h>
 11  #include <limits.h>
 12  #include <stdbool.h>
 13  #include <stddef.h>
 14  #include <stdio.h>
 15  #include <stdlib.h>
 16  #include <string.h>
 17  
 18  void *xmalloc(size_t size)
 19  {
 20  	void *p = malloc(size);
 21  	if (p == NULL) {
 22  		fprintf(stderr, "Failed to allocate memory\n");
 23  		abort();
 24  	}
 25  	return p;
 26  }
 27  
 28  char *to_chars(const CHAR16 uchars[], size_t size)
 29  {
 30  	char *chars = xmalloc(size / 2 + 1);
 31  
 32  	const CHAR16 *from = uchars;
 33  	char *to = chars;
 34  	while (*from != 0) {
 35  		CHAR16 uc = *from++;
 36  		if (uc < CHAR_MAX)
 37  			*to++ = uc;
 38  		else
 39  			*to++ = '?';
 40  	}
 41  
 42  	// In case there was no terminating NUL.
 43  	if (to != chars && to[-1] != '\0')
 44  		*to = '\0';
 45  
 46  	return chars;
 47  }
 48  
 49  CHAR16 *to_uchars(const char chars[], size_t *size)
 50  {
 51  	*size = (strlen(chars) + 1) * 2;
 52  	CHAR16 *uchars = xmalloc(*size);
 53  
 54  	const char *from = chars;
 55  	CHAR16 *to = uchars;
 56  	while (*from != '\0')
 57  		*to++ = *from++;
 58  	*to = 0;
 59  
 60  	return uchars;
 61  }
 62  
 63  bool str_eq(const char lhs[], const char rhs[])
 64  {
 65  	return strcmp(lhs, rhs) == 0;
 66  }
 67  
 68  struct mem_range_t map_file(const char path[], bool rw)
 69  {
 70  	struct mem_range_t range = {0};
 71  
 72  	int open_flags = rw ? O_RDWR : O_RDONLY;
 73  	int mmap_flags = rw ? PROT_READ | PROT_WRITE : PROT_READ;
 74  
 75  	int fd = open(path, open_flags);
 76  	if (fd == -1) {
 77  		fprintf(stderr, "Failed to open(): %s\n", strerror(errno));
 78  		return range;
 79  	}
 80  
 81  	struct stat stat_buf;
 82  	if (fstat(fd, &stat_buf) != 0) {
 83  		(void)close(fd);
 84  		fprintf(stderr, "Failed to fstat(): %s\n", strerror(errno));
 85  		return range;
 86  	}
 87  
 88  	if (stat_buf.st_size == 0) {
 89  		(void)close(fd);
 90  		fprintf(stderr, "Can't map an empty \"%s\" file\n", path);
 91  		return range;
 92  	}
 93  
 94  	uint8_t *mem = mmap(/*addr=*/NULL, stat_buf.st_size, mmap_flags,
 95  			    MAP_SHARED | MAP_POPULATE, fd, /*offset=*/0);
 96  	(void)close(fd);
 97  	if (mem == MAP_FAILED) {
 98  		fprintf(stderr, "Failed to mmap(): %s\n", strerror(errno));
 99  		return range;
100  	}
101  
102  	range.start = mem;
103  	range.length = stat_buf.st_size;
104  	return range;
105  }
106  
107  void unmap_file(struct mem_range_t store)
108  {
109  	if (munmap(store.start, store.length) != 0)
110  		fprintf(stderr, "Failed to munmap(): %s\n", strerror(errno));
111  }