aboutsummaryrefslogtreecommitdiffstats
path: root/tools/xenstore/utils.c
blob: 2bc40e009b3079324503c6d3e0c26a46839103c9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
#define _GNU_SOURCE
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <signal.h>

#include "utils.h"

void xprintf(const char *fmt, ...)
{
	static FILE *out = NULL;
	va_list args;
	if (!out)
		out = stderr;

	va_start(args, fmt);
	vfprintf(out, fmt, args);
	va_end(args);
	fflush(out);
}

void barf(const char *fmt, ...)
{
	char *str;
	va_list arglist;

	xprintf("FATAL: ");

	va_start(arglist, fmt);
	vasprintf(&str, fmt, arglist);
	va_end(arglist);

	xprintf("%s\n", str);
	free(str);
	exit(1);
}

void barf_perror(const char *fmt, ...)
{
	char *str;
	int err = errno;
	va_list arglist;

	xprintf("FATAL: ");

	va_start(arglist, fmt);
	vasprintf(&str, fmt, arglist);
	va_end(arglist);

	xprintf("%s: %s\n", str, strerror(err));
	free(str);
	exit(1);
}

void *_realloc_array(void *ptr, size_t size, size_t num)
{
	if (num >= SIZE_MAX/size)
		return NULL;
	return realloc_nofail(ptr, size * num);
}

void *realloc_nofail(void *ptr, size_t size)
{
	ptr = realloc(ptr, size);
	if (ptr)
		return ptr;
	barf("realloc of %zu failed", size);
}

void *malloc_nofail(size_t size)
{
	void *ptr = malloc(size);
	if (ptr)
		return ptr;
	barf("malloc of %zu failed", size);
}

/* This version adds one byte (for nul term) */
void *grab_file(const char *filename, unsigned long *size)
{
	unsigned int max = 16384;
	int ret, fd;
	void *buffer;

	if (streq(filename, "-"))
		fd = dup(STDIN_FILENO);
	else
		fd = open(filename, O_RDONLY, 0);

	if (fd < 0)
		return NULL;

	buffer = malloc(max+1);
	*size = 0;
	while ((ret = read(fd, buffer + *size, max - *size)) > 0) {
		*size += ret;
		if (*size == max)
			buffer = realloc(buffer, max *= 2 + 1);
	}
	if (ret < 0) {
		free(buffer);
		buffer = NULL;
	} else
		((char *)buffer)[*size] = '\0';
	close(fd);
	return buffer;
}

void release_file(void *data, unsigned long size __attribute__((unused)))
{
	free(data);
}