/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>


#if (NGX_HAVE_INET6)
static size_t ngx_inet6_ntop(u_char *p, u_char *text, size_t len);
#endif
static ngx_int_t ngx_parse_unix_domain_url(ngx_pool_t *pool, ngx_url_t *u);
static ngx_int_t ngx_parse_inet_url(ngx_pool_t *pool, ngx_url_t *u);
static ngx_int_t ngx_parse_inet6_url(ngx_pool_t *pool, ngx_url_t *u);


in_addr_t
ngx_inet_addr(u_char *text, size_t len)
{
    u_char      *p, c;
    in_addr_t    addr;
    ngx_uint_t   octet, n;

    addr = 0;
    octet = 0;
    n = 0;

    for (p = text; p < text + len; p++) {

        c = *p;

        if (c >= '0' && c <= '9') {
            octet = octet * 10 + (c - '0');
            continue;
        }

        if (c == '.' && octet < 256) {
            addr = (addr << 8) + octet;
            octet = 0;
            n++;
            continue;
        }

        return INADDR_NONE;
    }

    if (n != 3) {
        return INADDR_NONE;
    }

    if (octet < 256) {
        addr = (addr << 8) + octet;
        return htonl(addr);
    }

    return INADDR_NONE;
}


size_t
ngx_sock_ntop(struct sockaddr *sa, u_char *text, size_t len, ngx_uint_t port)
{
    u_char               *p;
    struct sockaddr_in   *sin;
#if (NGX_HAVE_INET6)
    size_t                n;
    struct sockaddr_in6  *sin6;
#endif

    switch (sa->sa_family) {

    case AF_INET:

        sin = (struct sockaddr_in *) sa;
        p = (u_char *) &sin->sin_addr;

        if (port) {
            p = ngx_snprintf(text, len, "%ud.%ud.%ud.%ud:%d",
                             p[0], p[1], p[2], p[3], ntohs(sin->sin_port));
        } else {
            p = ngx_snprintf(text, len, "%ud.%ud.%ud.%ud",
                             p[0], p[1], p[2], p[3]);
        }

        return (p - text);

#if (NGX_HAVE_INET6)

    case AF_INET6:

        sin6 = (struct sockaddr_in6 *) sa;

        n = 0;

        if (port) {
            text[n++] = '[';
        }

        n = ngx_inet6_ntop((u_char *) &sin6->sin6_addr, &text[n], len);

        if (port) {
            n = ngx_sprintf(&text[1 + n], "]:%d",
                            ntohs(sin6->sin6_port)) - text;
        }

        return n;
#endif

    default:
        return 0;
    }
}


size_t
ngx_inet_ntop(int family, void *addr, u_char *text, size_t len)
{
    u_char  *p;

    switch (family) {

    case AF_INET:

        p = addr;

        return ngx_snprintf(text, len, "%ud.%ud.%ud.%ud",
                            p[0], p[1], p[2], p[3])
               - text;

#if (NGX_HAVE_INET6)

    case AF_INET6:
        return ngx_inet6_ntop(addr, text, len);

#endif

    default:
        return 0;
    }
}


#if (NGX_HAVE_INET6)

static size_t
ngx_inet6_ntop(u_char *p, u_char *text, size_t len)
{
    u_char      *dst;
    size_t       max, n;
    ngx_uint_t   i, zero, last;

    if (len < NGX_INET6_ADDRSTRLEN) {
        return 0;
    }

    zero = (ngx_uint_t) -1;
    last = (ngx_uint_t) -1;
    max = 1;
    n = 0;

    for (i = 0; i < 16; i += 2) {

        if (p[i] || p[i + 1]) {

            if (max < n) {
                zero = last;
                max = n;
            }

            n = 0;
            continue;
        }

        if (n++ == 0) {
            last = i;
        }
    }

    if (max < n) {
        zero = last;
        max = n;
    }

    dst = text;
    n = 16;

    if (zero == 0) {

        if ((max == 5 && p[10] == 0xff && p[11] == 0xff)
            || (max == 6)
            || (max == 7 && p[14] != 0 && p[15] != 1))
        {
            n = 12;
        }

        *dst++ = ':';
    }

    for (i = 0; i < n; i += 2) {

        if (i == zero) {
            *dst++ = ':';
            i += (max - 1) * 2;
            continue;
        }

        dst = ngx_sprintf(dst, "%uxi", p[i] * 256 + p[i + 1]);

        if (i < 14) {
            *dst++ = ':';
        }
    }

    if (n == 12) {
        dst = ngx_sprintf(dst, "%ud.%ud.%ud.%ud", p[12], p[13], p[14], p[15]);
    }

    return dst - text;
}

#endif


/* AF_INET only */

ngx_int_t
ngx_ptocidr(ngx_str_t *text, ngx_cidr_t *cidr)
{
    u_char     *addr, *mask, *last;
    ngx_int_t   shift;

    addr = text->data;
    last = addr + text->len;

    mask = ngx_strlchr(addr, last, '/');

    cidr->u.in.addr = ngx_inet_addr(addr, (mask ? mask : last) - addr);

    if (cidr->u.in.addr == INADDR_NONE) {
        return NGX_ERROR;
    }

    if (mask == NULL) {
        cidr->family = AF_INET;
        cidr->u.in.mask = 0xffffffff;
        return NGX_OK;
    }

    mask++;

    shift = ngx_atoi(mask, last - mask);
    if (shift == NGX_ERROR) {
        return NGX_ERROR;
    }

    cidr->family = AF_INET;

    if (shift == 0) {

        /* the x86 compilers use the shl instruction that shifts by modulo 32 */

        cidr->u.in.mask = 0;

        if (cidr->u.in.addr == 0) {
            return NGX_OK;
        }

        return NGX_DONE;
    }

    cidr->u.in.mask = htonl((ngx_uint_t) (0 - (1 << (32 - shift))));

    if (cidr->u.in.addr == (cidr->u.in.addr & cidr->u.in.mask)) {
        return NGX_OK;
    }

    cidr->u.in.addr &= cidr->u.in.mask;

    return NGX_DONE;
}


ngx_int_t
ngx_parse_url(ngx_pool_t *pool, ngx_url_t *u)
{
    u_char  *p;

    p = u->url.data;

    if (ngx_strncasecmp(p, (u_char *) "unix:", 5) == 0) {
        return ngx_parse_unix_domain_url(pool, u);
    }

    if ((p[0] == ':' || p[0] == '/') && !u->listen) {
        u->err = "invalid host";
        return NGX_ERROR;
    }

    if (p[0] == '[') {
        return ngx_parse_inet6_url(pool, u);
    }

    return ngx_parse_inet_url(pool, u);
}


static ngx_int_t
ngx_parse_unix_domain_url(ngx_pool_t *pool, ngx_url_t *u)
{
#if (NGX_HAVE_UNIX_DOMAIN)
    u_char              *path, *uri, *last;
    size_t               len;
    struct sockaddr_un  *saun;

    len = u->url.len;
    path = u->url.data;

    path += 5;
    len -= 5;

    if (u->uri_part) {

        last = path + len;
        uri = ngx_strlchr(path, last, ':');

        if (uri) {
            len = uri - path;
            uri++;
            u->uri.len = last - uri;
            u->uri.data = uri;
        }
    }

    if (len == 0) {
        u->err = "no path in the unix domain socket";
        return NGX_ERROR;
    }

    u->host.len = len++;
    u->host.data = path;

    if (len > sizeof(saun->sun_path)) {
        u->err = "too long path in the unix domain socket";
        return NGX_ERROR;
    }

    u->socklen = sizeof(struct sockaddr_un);
    saun = (struct sockaddr_un *) &u->sockaddr;
    saun->sun_family = AF_UNIX;
    (void) ngx_cpystrn((u_char *) saun->sun_path, path, len);

    u->addrs = ngx_pcalloc(pool, sizeof(ngx_peer_addr_t));
    if (u->addrs == NULL) {
        return NGX_ERROR;
    }

    saun = ngx_pcalloc(pool, sizeof(struct sockaddr_un));
    if (saun == NULL) {
        return NGX_ERROR;
    }

    u->family = AF_UNIX;
    u->naddrs = 1;

    saun->sun_family = AF_UNIX;
    (void) ngx_cpystrn((u_char *) saun->sun_path, path, len);

    u->addrs[0].sockaddr = (struct sockaddr *) saun;
    u->addrs[0].socklen = sizeof(struct sockaddr_un);
    u->addrs[0].name.len = len + 4;
    u->addrs[0].name.data = u->url.data;

    return NGX_OK;

#else

    u->err = "the unix domain sockets are not supported on this platform";

    return NGX_ERROR;

#endif
}


static ngx_int_t
ngx_parse_inet_url(ngx_pool_t *pool, ngx_url_t *u)
{
    u_char              *p, *host, *port, *last, *uri, *args;
    size_t               len;
    ngx_int_t            n;
    struct hostent      *h;
    struct sockaddr_in  *sin;

    u->socklen = sizeof(struct sockaddr_in);
    sin = (struct sockaddr_in *) &u->sockaddr;
    sin->sin_family = AF_INET;

    u->family = AF_INET;

    host = u->url.data;

    last = host + u->url.len;

    port = ngx_strlchr(host, last, ':');

    uri = ngx_strlchr(host, last, '/');

    args = ngx_strlchr(host, last, '?');

    if (args) {
        if (uri == NULL) {
            uri = args;

        } else if (args < uri) {
            uri = args;
        }
    }

    if (uri) {
        if (u->listen || !u->uri_part) {
            u->err = "invalid host";
            return NGX_ERROR;
        }

        u->uri.len = last - uri;
        u->uri.data = uri;

        last = uri;

        if (uri < port) {
            port = NULL;
        }
    }

    if (port) {
        port++;

        len = last - port;

        if (len == 0) {
            u->err = "invalid port";
            return NGX_ERROR;
        }

        n = ngx_atoi(port, len);

        if (n < 1 || n > 65536) {
            u->err = "invalid port";
            return NGX_ERROR;
        }

        u->port = (in_port_t) n;
        sin->sin_port = htons((in_port_t) n);

        u->port_text.len = len;
        u->port_text.data = port;

        last = port - 1;

    } else {
        if (uri == NULL) {

            if (u->listen) {

                /* test value as port only */

                n = ngx_atoi(host, last - host);

                if (n != NGX_ERROR) {

                    if (n < 1 || n > 65536) {
                        u->err = "invalid port";
                        return NGX_ERROR;
                    }

                    u->port = (in_port_t) n;
                    sin->sin_port = htons((in_port_t) n);

                    u->port_text.len = last - host;
                    u->port_text.data = host;

                    u->wildcard = 1;

                    return NGX_OK;
                }
            }
        }

        u->no_port = 1;
    }

    len = last - host;

    if (len == 0) {
        u->err = "no host";
        return NGX_ERROR;
    }

    if (len == 1 && *host == '*') {
        len = 0;
    }

    u->host.len = len;
    u->host.data = host;

    if (u->no_resolve) {
        return NGX_OK;
    }

    if (len++) {

        p = ngx_alloc(len, pool->log);
        if (p == NULL) {
            return NGX_ERROR;
        }

        (void) ngx_cpystrn(p, host, len);

        sin->sin_addr.s_addr = inet_addr((const char *) p);

        if (sin->sin_addr.s_addr == INADDR_NONE) {
            h = gethostbyname((const char *) p);

            if (h == NULL || h->h_addr_list[0] == NULL) {
                ngx_free(p);
                u->err = "host not found";
                return NGX_ERROR;
            }

            sin->sin_addr.s_addr = *(in_addr_t *) (h->h_addr_list[0]);
        }

        if (sin->sin_addr.s_addr == INADDR_ANY) {
            u->wildcard = 1;
        }

        ngx_free(p);

    } else {
        sin->sin_addr.s_addr = INADDR_ANY;
        u->wildcard = 1;
    }

    if (u->no_port) {
        u->port = u->default_port;
        sin->sin_port = htons(u->default_port);
    }

    if (u->listen) {
        return NGX_OK;
    }

    if (ngx_inet_resolve_host(pool, u) != NGX_OK) {
        return NGX_ERROR;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_parse_inet6_url(ngx_pool_t *pool, ngx_url_t *u)
{
#if (NGX_HAVE_INET6)
    int                   rc;
    u_char               *p, *host, *port, *last, *uri;
    size_t                len;
    ngx_int_t             n;
    struct sockaddr_in6  *sin6;

    u->socklen = sizeof(struct sockaddr_in6);
    sin6 = (struct sockaddr_in6 *) &u->sockaddr;
    sin6->sin6_family = AF_INET6;

    host = u->url.data + 1;

    last = u->url.data + u->url.len;

    p = ngx_strlchr(host, last, ']');

    if (p == NULL) {
        u->err = "invalid host";
        return NGX_ERROR;
    }

    if (last - p) {

        port = p + 1;

        uri = ngx_strlchr(port, last, '/');

        if (uri) {
            if (u->listen || !u->uri_part) {
                u->err = "invalid host";
                return NGX_ERROR;
            }

            u->uri.len = last - uri;
            u->uri.data = uri;
        }

        if (*port == ':') {
            port++;

            len = last - port;

            if (len == 0) {
                u->err = "invalid port";
                return NGX_ERROR;
            }

            n = ngx_atoi(port, len);

            if (n < 1 || n > 65536) {
                u->err = "invalid port";
                return NGX_ERROR;
            }

            u->port = (in_port_t) n;
            sin6->sin6_port = htons((in_port_t) n);

            u->port_text.len = len;
            u->port_text.data = port;

        } else {
            u->no_port = 1;
        }
    }

    len = p - host;

    if (len == 0) {
        u->err = "no host";
        return NGX_ERROR;
    }

    u->host.len = len++;
    u->host.data = host;

    p = ngx_alloc(len, pool->log);
    if (p == NULL) {
        return NGX_ERROR;
    }

    (void) ngx_cpystrn(p, host, len);

#if (NGX_WIN32)

    rc = WSAStringToAddress((char *) p, AF_INET6, NULL,
                            (SOCKADDR *) sin6, &u->socklen);
    rc = !rc;

    if (u->port) {
        sin6->sin6_port = htons(u->port);
    }

#else

    rc = inet_pton(AF_INET6, (const char *) p, &sin6->sin6_addr);

#endif

    ngx_free(p);

    if (rc == 0) {
        u->err = "invalid IPv6 address";
        return NGX_ERROR;
    }

    if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
        u->wildcard = 1;
    }

    u->family = AF_INET6;

    if (u->no_resolve) {
        return NGX_OK;
    }

    if (u->no_port) {
        u->port = u->default_port;
        sin6->sin6_port = htons(u->default_port);
    }

    return NGX_OK;

#else

    u->err = "the INET6 sockets are not supported on this platform";

    return NGX_ERROR;

#endif
}


ngx_int_t
ngx_inet_resolve_host(ngx_pool_t *pool, ngx_url_t *u)
{
    u_char              *p, *host;
    size_t               len;
    in_port_t            port;
    in_addr_t            in_addr;
    ngx_uint_t           i;
    struct hostent      *h;
    struct sockaddr_in  *sin;

    host = ngx_alloc(u->host.len + 1, pool->log);
    if (host == NULL) {
        return NGX_ERROR;
    }

    (void) ngx_cpystrn(host, u->host.data, u->host.len + 1);

    /* AF_INET only */

    port = htons(u->port);

    in_addr = inet_addr((char *) host);

    if (in_addr == INADDR_NONE) {
        h = gethostbyname((char *) host);

        ngx_free(host);

        if (h == NULL || h->h_addr_list[0] == NULL) {
            u->err = "host not found";
            return NGX_ERROR;
        }

        if (u->one_addr == 0) {
            for (i = 0; h->h_addr_list[i] != NULL; i++) { /* void */ }

        } else {
            i = 1;
        }

        /* MP: ngx_shared_palloc() */

        u->addrs = ngx_pcalloc(pool, i * sizeof(ngx_peer_addr_t));
        if (u->addrs == NULL) {
            return NGX_ERROR;
        }

        u->naddrs = i;

        for (i = 0; h->h_addr_list[i] != NULL; i++) {

            sin = ngx_pcalloc(pool, sizeof(struct sockaddr_in));
            if (sin == NULL) {
                return NGX_ERROR;
            }

            sin->sin_family = AF_INET;
            sin->sin_port = port;
            sin->sin_addr.s_addr = *(in_addr_t *) (h->h_addr_list[i]);

            u->addrs[i].sockaddr = (struct sockaddr *) sin;
            u->addrs[i].socklen = sizeof(struct sockaddr_in);

            len = NGX_INET_ADDRSTRLEN + sizeof(":65535") - 1;

            p = ngx_pnalloc(pool, len);
            if (p == NULL) {
                return NGX_ERROR;
            }

            len = ngx_sock_ntop((struct sockaddr *) sin, p, len, 1);

            u->addrs[i].name.len = len;
            u->addrs[i].name.data = p;
        }

    } else {

        ngx_free(host);

        /* MP: ngx_shared_palloc() */

        u->addrs = ngx_pcalloc(pool, sizeof(ngx_peer_addr_t));
        if (u->addrs == NULL) {
            return NGX_ERROR;
        }

        sin = ngx_pcalloc(pool, sizeof(struct sockaddr_in));
        if (sin == NULL) {
            return NGX_ERROR;
        }

        u->naddrs = 1;

        sin->sin_family = AF_INET;
        sin->sin_port = port;
        sin->sin_addr.s_addr = in_addr;

        u->addrs[0].sockaddr = (struct sockaddr *) sin;
        u->addrs[0].socklen = sizeof(struct sockaddr_in);

        p = ngx_pnalloc(pool, u->host.len + sizeof(":65535") - 1);
        if (p == NULL) {
            return NGX_ERROR;
        }

        u->addrs[0].name.len = ngx_sprintf(p, "%V:%d",
                                           &u->host, ntohs(port)) - p;
        u->addrs[0].name.data = p;
    }

    return NGX_OK;
}