root/url.c

DEFINITIONS

1. is_urlschemechar
2. is_url
3. url_decode_char
4. url_decode_internal
5. url_decode
6. url_decode_mem
7. url_decode_parameter_name
8. url_decode_parameter_value
9. end_url_with_slash
10. str_end_url_with_slash

#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);
        if (buf->len && buf->buf[buf->len - 1] != '/')
                strbuf_addch(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);
}