aboutsummaryrefslogtreecommitdiff
path: root/url.c
blob: 2d89ad190cfe1c57cd20194661329551ff229993 (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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
#include "cache.h"
#include "url.h"

int is_urlschemechar(int first_flag, int ch)
{
	/*
	 * The set of valid URL schemes, as per STD66 (RFC3986) is
	 * '[A-Za-z][A-Za-z0-9+.-]*'. But use sightly looser check
	 * of '[A-Za-z0-9][A-Za-z0-9+.-]*' because earlier version
	 * of check used '[A-Za-z0-9]+' so not to break any remote
	 * helpers.
	 */
	int alphanumeric, special;
	alphanumeric = ch > 0 && isalnum(ch);
	special = ch == '+' || ch == '-' || ch == '.';
	return alphanumeric || (!first_flag && special);
}

int is_url(const char *url)
{
	/* Is "scheme" part reasonable? */
	if (!url || !is_urlschemechar(1, *url++))
		return 0;
	while (*url && *url != ':') {
		if (!is_urlschemechar(0, *url++))
			return 0;
	}
	/* We've seen "scheme"; we want colon-slash-slash */
	return (url[0] == ':' && url[1] == '/' && url[2] == '/');
}

static int url_decode_char(const char *q)
{
	int i;
	unsigned char val = 0;
	for (i = 0; i < 2; i++) {
		unsigned char c = *q++;
		val <<= 4;
		if (c >= '0' && c <= '9')
			val += c - '0';
		else if (c >= 'a' && c <= 'f')
			val += c - 'a' + 10;
		else if (c >= 'A' && c <= 'F')
			val += c - 'A' + 10;
		else
			return -1;
	}
	return val;
}

static char *url_decode_internal(const char **query, int len,
				 const char *stop_at, struct strbuf *out,
				 int decode_plus)
{
	const char *q = *query;

	while (len) {
		unsigned char c = *q;

		if (!c)
			break;
		if (stop_at && strchr(stop_at, c)) {
			q++;
			len--;
			break;
		}

		if (c == '%') {
			int val = url_decode_char(q + 1);
			if (0 <= val) {
				strbuf_addch(out, val);
				q += 3;
				len -= 3;
				continue;
			}
		}

		if (decode_plus && c == '+')
			strbuf_addch(out, ' ');
		else
			strbuf_addch(out, c);
		q++;
		len--;
	}
	*query = q;
	return strbuf_detach(out, NULL);
}

char *url_decode(const char *url)
{
	return url_decode_mem(url, strlen(url));
}

char *url_decode_mem(const char *url, int len)
{
	struct strbuf out = STRBUF_INIT;
	const char *colon = memchr(url, ':', len);

	/* Skip protocol part if present */
	if (colon && url < colon) {
		strbuf_add(&out, url, colon - url);
		len -= colon - url;
		url = colon;
	}
	return url_decode_internal(&url, len, NULL, &out, 0);
}

char *url_decode_parameter_name(const char **query)
{
	struct strbuf out = STRBUF_INIT;
	return url_decode_internal(query, -1, "&=", &out, 1);
}

char *url_decode_parameter_value(const char **query)
{
	struct strbuf out = STRBUF_INIT;
	return url_decode_internal(query, -1, "&", &out, 1);
}

void end_url_with_slash(struct strbuf *buf, const char *url)
{
	strbuf_addstr(buf, url);
	strbuf_complete(buf, '/');
}

void str_end_url_with_slash(const char *url, char **dest) {
	struct strbuf buf = STRBUF_INIT;
	end_url_with_slash(&buf, url);
	free(*dest);
	*dest = strbuf_detach(&buf, NULL);
}