url.con commit glossary: improve description of SHA-1 related topics (3ab5012)
   1#include "cache.h"
   2#include "url.h"
   3
   4int is_urlschemechar(int first_flag, int ch)
   5{
   6        /*
   7         * The set of valid URL schemes, as per STD66 (RFC3986) is
   8         * '[A-Za-z][A-Za-z0-9+.-]*'. But use sightly looser check
   9         * of '[A-Za-z0-9][A-Za-z0-9+.-]*' because earlier version
  10         * of check used '[A-Za-z0-9]+' so not to break any remote
  11         * helpers.
  12         */
  13        int alphanumeric, special;
  14        alphanumeric = ch > 0 && isalnum(ch);
  15        special = ch == '+' || ch == '-' || ch == '.';
  16        return alphanumeric || (!first_flag && special);
  17}
  18
  19int is_url(const char *url)
  20{
  21        /* Is "scheme" part reasonable? */
  22        if (!url || !is_urlschemechar(1, *url++))
  23                return 0;
  24        while (*url && *url != ':') {
  25                if (!is_urlschemechar(0, *url++))
  26                        return 0;
  27        }
  28        /* We've seen "scheme"; we want colon-slash-slash */
  29        return (url[0] == ':' && url[1] == '/' && url[2] == '/');
  30}
  31
  32static int url_decode_char(const char *q)
  33{
  34        int i;
  35        unsigned char val = 0;
  36        for (i = 0; i < 2; i++) {
  37                unsigned char c = *q++;
  38                val <<= 4;
  39                if (c >= '0' && c <= '9')
  40                        val += c - '0';
  41                else if (c >= 'a' && c <= 'f')
  42                        val += c - 'a' + 10;
  43                else if (c >= 'A' && c <= 'F')
  44                        val += c - 'A' + 10;
  45                else
  46                        return -1;
  47        }
  48        return val;
  49}
  50
  51static char *url_decode_internal(const char **query, int len,
  52                                 const char *stop_at, struct strbuf *out,
  53                                 int decode_plus)
  54{
  55        const char *q = *query;
  56
  57        while (len) {
  58                unsigned char c = *q;
  59
  60                if (!c)
  61                        break;
  62                if (stop_at && strchr(stop_at, c)) {
  63                        q++;
  64                        len--;
  65                        break;
  66                }
  67
  68                if (c == '%') {
  69                        int val = url_decode_char(q + 1);
  70                        if (0 <= val) {
  71                                strbuf_addch(out, val);
  72                                q += 3;
  73                                len -= 3;
  74                                continue;
  75                        }
  76                }
  77
  78                if (decode_plus && c == '+')
  79                        strbuf_addch(out, ' ');
  80                else
  81                        strbuf_addch(out, c);
  82                q++;
  83                len--;
  84        }
  85        *query = q;
  86        return strbuf_detach(out, NULL);
  87}
  88
  89char *url_decode(const char *url)
  90{
  91        return url_decode_mem(url, strlen(url));
  92}
  93
  94char *url_decode_mem(const char *url, int len)
  95{
  96        struct strbuf out = STRBUF_INIT;
  97        const char *colon = memchr(url, ':', len);
  98
  99        /* Skip protocol part if present */
 100        if (colon && url < colon) {
 101                strbuf_add(&out, url, colon - url);
 102                len -= colon - url;
 103                url = colon;
 104        }
 105        return url_decode_internal(&url, len, NULL, &out, 0);
 106}
 107
 108char *url_decode_parameter_name(const char **query)
 109{
 110        struct strbuf out = STRBUF_INIT;
 111        return url_decode_internal(query, -1, "&=", &out, 1);
 112}
 113
 114char *url_decode_parameter_value(const char **query)
 115{
 116        struct strbuf out = STRBUF_INIT;
 117        return url_decode_internal(query, -1, "&", &out, 1);
 118}
 119
 120void end_url_with_slash(struct strbuf *buf, const char *url)
 121{
 122        strbuf_addstr(buf, url);
 123        if (buf->len && buf->buf[buf->len - 1] != '/')
 124                strbuf_addstr(buf, "/");
 125}
 126
 127void str_end_url_with_slash(const char *url, char **dest) {
 128        struct strbuf buf = STRBUF_INIT;
 129        end_url_with_slash(&buf, url);
 130        free(*dest);
 131        *dest = strbuf_detach(&buf, NULL);
 132}