tos_values.c revision 4ded0f11d382c37a57c04077f453b3978eeded17 
1#include <stdbool.h>
2#include <stdint.h>
3#include <stdio.h>
4
5struct tos_value_mask {
6	uint8_t value, mask;
7};
8
9static const struct tos_symbol_info {
10	unsigned char value;
11	const char *name;
12} tos_symbol_names[] = {
13	{IPTOS_LOWDELAY,    "Minimize-Delay"},
14	{IPTOS_THROUGHPUT,  "Maximize-Throughput"},
15	{IPTOS_RELIABILITY, "Maximize-Reliability"},
16	{IPTOS_MINCOST,     "Minimize-Cost"},
17	{IPTOS_NORMALSVC,   "Normal-Service"},
18	{ .name = NULL }
19};
20
21/*
22 * tos_parse_numeric - parse sth. like "15/255"
23 *
24 * @s:		input string
25 * @info:	accompanying structure
26 * @bits:	number of bits that are allowed
27 *		(8 for IPv4 TOS field, 4 for IPv6 Priority Field)
28 */
29static bool tos_parse_numeric(const char *str, struct tos_value_mask *tvm,
30                              unsigned int bits)
31{
32	const unsigned int max = (1 << bits) - 1;
33	unsigned int value;
34	char *end;
35
36	strtonum(str, &end, &value, 0, max);
37	tvm->value = value;
38	tvm->mask  = max;
39
40	if (*end == '/') {
41		const char *p = end + 1;
42
43		if (!strtonum(p, &end, &value, 0, max))
44			exit_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"",
45			           str);
46		tvm->mask = value;
47	}
48
49	if (*end != '\0')
50		exit_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"", str);
51	return true;
52}
53
54static bool tos_parse_symbolic(const char *str, struct tos_value_mask *tvm,
55    unsigned int def_mask)
56{
57	const unsigned int max = 255;
58	const struct tos_symbol_info *symbol;
59	char *tmp;
60
61	if (strtonum(str, &tmp, NULL, 0, max))
62		return tos_parse_numeric(str, tvm, max);
63
64	/* Do not consider ECN bits */
65	tvm->mask = def_mask;
66	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
67		if (strcasecmp(str, symbol->name) == 0) {
68			tvm->value = symbol->value;
69			return true;
70		}
71
72	exit_error(PARAMETER_PROBLEM, "Symbolic name \"%s\" is unknown", str);
73	return false;
74}
75
76static bool tos_try_print_symbolic(const char *prefix,
77    u_int8_t value, u_int8_t mask)
78{
79	const struct tos_symbol_info *symbol;
80
81	if (mask != 0x3F)
82		return false;
83
84	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
85		if (value == symbol->value) {
86			printf("%s%s ", prefix, symbol->name);
87			return true;
88		}
89
90	return false;
91}
92