vhost.c

Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相兼容的web服务器.这里给出的是Apache HTTP服务器的源码。

    new->names = NULL;
    new->server = s;
    new->sar = sar;
    new->next = NULL;
    return new;
}


static name_chain *new_name_chain(apr_pool_t *p,
                                  server_rec *s, server_addr_rec *sar)
{
    name_chain *new;

    new = apr_palloc(p, sizeof(*new));
    new->server = s;
    new->sar = sar;
    new->next = NULL;
    return new;
}


static APR_INLINE ipaddr_chain *find_ipaddr(apr_sockaddr_t *sa)
{
    unsigned bucket;
    ipaddr_chain *trav;

    /* scan the hash apr_table_t for an exact match first */
    bucket = hash_addr(sa);
    for (trav = iphash_table[bucket]; trav; trav = trav->next) {
        server_addr_rec *sar = trav->sar;
        apr_sockaddr_t *cur = sar->host_addr;

        if (cur->port == 0 || sa->port == 0 || cur->port == sa->port) {
            if (apr_sockaddr_equal(cur, sa)) {
                return trav;
            }
        }    
    }
    return NULL;
}

static ipaddr_chain *find_default_server(apr_port_t port)
{
    server_addr_rec *sar;
    ipaddr_chain *trav;

    for (trav = default_list; trav; trav = trav->next) {
        sar = trav->sar;
        if (sar->host_port == 0 || sar->host_port == port) {
            /* match! */
            return trav;
        }
    }
    return NULL;
}

static void dump_a_vhost(apr_file_t *f, ipaddr_chain *ic)
{
    name_chain *nc;
    int len;
    char buf[MAX_STRING_LEN];
    apr_sockaddr_t *ha = ic->sar->host_addr;

    if (ha->family == APR_INET &&
        ha->sa.sin.sin_addr.s_addr == DEFAULT_VHOST_ADDR) {
        len = apr_snprintf(buf, sizeof(buf), "_default_:%u",
                           ic->sar->host_port);
    }
    else if (ha->family == APR_INET &&
             ha->sa.sin.sin_addr.s_addr == INADDR_ANY) {
        len = apr_snprintf(buf, sizeof(buf), "*:%u",
                           ic->sar->host_port);
    }
    else {
        len = apr_snprintf(buf, sizeof(buf), "%pI", ha);
    }
    if (ic->sar->host_port == 0) {
        buf[len-1] = '*';
    }
    if (ic->names == NULL) {
        apr_file_printf(f, "%-22s %s (%s:%u)\n", buf,
                        ic->server->server_hostname,
                        ic->server->defn_name, ic->server->defn_line_number);
        return;
    }
    apr_file_printf(f, "%-22s is a NameVirtualHost\n"
                    "%8s default server %s (%s:%u)\n",
                    buf, "", ic->server->server_hostname,
                    ic->server->defn_name, ic->server->defn_line_number);
    for (nc = ic->names; nc; nc = nc->next) {
        if (nc->sar->host_port) {
            apr_file_printf(f, "%8s port %u ", "", nc->sar->host_port);
        }
        else {
            apr_file_printf(f, "%8s port * ", "");
        }
        apr_file_printf(f, "namevhost %s (%s:%u)\n",
                        nc->server->server_hostname,
                        nc->server->defn_name, nc->server->defn_line_number);
    }
}

static void dump_vhost_config(apr_file_t *f)
{
    ipaddr_chain *ic;
    int i;

    apr_file_printf(f, "VirtualHost configuration:\n");
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        for (ic = iphash_table[i]; ic; ic = ic->next) {
            dump_a_vhost(f, ic);
        }
    }
    if (default_list) {
        apr_file_printf(f, "wildcard NameVirtualHosts and _default_ servers:\n");
        for (ic = default_list; ic; ic = ic->next) {
            dump_a_vhost(f, ic);
        }
    }
}

/*
 * Two helper functions for ap_fini_vhost_config()
 */
static int add_name_vhost_config(apr_pool_t *p, server_rec *main_s,
                                 server_rec *s, server_addr_rec *sar,
                                 ipaddr_chain *ic)
{
    /* the first time we encounter a NameVirtualHost address
     * ic->server will be NULL, on subsequent encounters
     * ic->names will be non-NULL.
     */
    if (ic->names || ic->server == NULL) {
        name_chain *nc = new_name_chain(p, s, sar);
        nc->next = ic->names;
        ic->names = nc;
        ic->server = s;
        if (sar->host_port != ic->sar->host_port) {
            /* one of the two is a * port, the other isn't */
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, main_s,
                         "VirtualHost %s:%u -- mixing * "
                         "ports and non-* ports with "
                         "a NameVirtualHost address is not supported,"
                         " proceeding with undefined results",
                         sar->virthost, sar->host_port);
        }
        return 1;
    }
    else {
        /* IP-based vhosts are handled by the caller */
        return 0;
    }
}

static void remove_unused_name_vhosts(server_rec *main_s, ipaddr_chain **pic)
{
    while (*pic) {
        ipaddr_chain *ic = *pic;
        
        if (ic->server == NULL) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_s,
                         "NameVirtualHost %s:%u has no VirtualHosts",
                         ic->sar->virthost, ic->sar->host_port);
            *pic = ic->next;
        }
        else if (ic->names == NULL) {
            /* if server != NULL and names == NULL then we're done
             * looking at NameVirtualHosts
             */
            break;
        }
        else {
            pic = &ic->next;
        }
    }
}

/* compile the tables and such we need to do the run-time vhost lookups */
AP_DECLARE(void) ap_fini_vhost_config(apr_pool_t *p, server_rec *main_s)
{
    server_addr_rec *sar;
    int has_default_vhost_addr;
    server_rec *s;
    int i;
    ipaddr_chain **iphash_table_tail[IPHASH_TABLE_SIZE];

    /* terminate the name_vhost list */
    *name_vhost_list_tail = NULL;

    /* Main host first */
    s = main_s;

    if (!s->server_hostname) {
        s->server_hostname = ap_get_local_host(p);
    }

    /* initialize the tails */
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        iphash_table_tail[i] = &iphash_table[i];
    }

    /* The first things to go into the hash apr_table_t are the NameVirtualHosts
     * Since name_vhost_list is in the same order that the directives
     * occured in the config file, we'll copy it in that order.
     */
    for (sar = name_vhost_list; sar; sar = sar->next) {
        char inaddr_any[16] = {0}; /* big enough to handle IPv4 or IPv6 */
        unsigned bucket = hash_addr(sar->host_addr);
        ipaddr_chain *ic = new_ipaddr_chain(p, NULL, sar);

        if (memcmp(sar->host_addr->ipaddr_ptr, inaddr_any, 
                   sar->host_addr->ipaddr_len)) { /* not IN[6]ADDR_ANY */
            *iphash_table_tail[bucket] = ic;
            iphash_table_tail[bucket] = &ic->next;
        }
        else {
            /* A wildcard NameVirtualHost goes on the default_list so
             * that it can catch incoming requests on any address.
             */
            ic->next = default_list;
            default_list = ic;
        }
        /* Notice that what we've done is insert an ipaddr_chain with
         * both server and names NULL. This fact is used to spot name-
         * based vhosts in add_name_vhost_config().
         */
    }

    /* The next things to go into the hash apr_table_t are the virtual hosts
     * themselves.  They're listed off of main_s->next in the reverse
     * order they occured in the config file, so we insert them at
     * the iphash_table_tail but don't advance the tail.
     */

    for (s = main_s->next; s; s = s->next) {
        has_default_vhost_addr = 0;
        for (sar = s->addrs; sar; sar = sar->next) {
            ipaddr_chain *ic;
            char inaddr_any[16] = {0}; /* big enough to handle IPv4 or IPv6 */

            if ((sar->host_addr->family == AF_INET &&
                 sar->host_addr->sa.sin.sin_addr.s_addr == DEFAULT_VHOST_ADDR)
                || !memcmp(sar->host_addr->ipaddr_ptr, inaddr_any, sar->host_addr->ipaddr_len)) {
                ic = find_default_server(sar->host_port);
                if (!ic || !add_name_vhost_config(p, main_s, s, sar, ic)) {
                    if (ic && ic->sar->host_port != 0) {
                        ap_log_error(APLOG_MARK, APLOG_WARNING,
                                     0, main_s, "_default_ VirtualHost "
                                     "overlap on port %u, the first has "
                                     "precedence", sar->host_port);
                    }
                    ic = new_ipaddr_chain(p, s, sar);
                    ic->next = default_list;
                    default_list = ic;
                }
                has_default_vhost_addr = 1;
            }
            else {
                /* see if it matches something we've already got */
                ic = find_ipaddr(sar->host_addr);

                if (!ic) {
                    unsigned bucket = hash_addr(sar->host_addr);

                    ic = new_ipaddr_chain(p, s, sar);
                    ic->next = *iphash_table_tail[bucket];
                    *iphash_table_tail[bucket] = ic;
                }
                else if (!add_name_vhost_config(p, main_s, s, sar, ic)) {
                    ap_log_error(APLOG_MARK, APLOG_WARNING,
                                 0, main_s, "VirtualHost %s:%u overlaps "
                                 "with VirtualHost %s:%u, the first has "
                                 "precedence, perhaps you need a "
                                 "NameVirtualHost directive",
                                 sar->virthost, sar->host_port,
                                 ic->sar->virthost, ic->sar->host_port);
                    ic->sar = sar;
                    ic->server = s;
                }
            }
        }

        /* Ok now we want to set up a server_hostname if the user was
         * silly enough to forget one.
         * XXX: This is silly we should just crash and burn.
         */
        if (!s->server_hostname) {
            if (has_default_vhost_addr) {
                s->server_hostname = main_s->server_hostname;
            }
            else if (!s->addrs) {
                /* what else can we do?  at this point this vhost has
                    no configured name, probably because they used
                    DNS in the VirtualHost statement.  It's disabled
                    anyhow by the host matching code.  -djg */
                s->server_hostname =
                    apr_pstrdup(p, "bogus_host_without_forward_dns");
            }
            else {
                apr_status_t rv;
                char *hostname;

                rv = apr_getnameinfo(&hostname, s->addrs->host_addr, 0);
                if (rv == APR_SUCCESS) {
                    s->server_hostname = apr_pstrdup(p, hostname);
                }
                else {
                    /* again, what can we do?  They didn't specify a
                       ServerName, and their DNS isn't working. -djg */
                    char *ipaddr_str;

                    apr_sockaddr_ip_get(&ipaddr_str, s->addrs->host_addr);
                    ap_log_error(APLOG_MARK, APLOG_ERR, rv, main_s,
                                 "Failed to resolve server name "
                                 "for %s (check DNS) -- or specify an explicit "
                                 "ServerName",
                                 ipaddr_str);
                    s->server_hostname =
                        apr_pstrdup(p, "bogus_host_without_reverse_dns");
                }
            }
        }
    }

    /* now go through and delete any NameVirtualHosts that didn't have any
     * hosts associated with them.  Lamers.
     */
    for (i = 0; i < IPHASH_TABLE_SIZE; ++i) {
        remove_unused_name_vhosts(main_s, &iphash_table[i]);
    }
    remove_unused_name_vhosts(main_s, &default_list);

#ifdef IPHASH_STATISTICS
    dump_iphash_statistics(main_s);
#endif
    if (ap_exists_config_define("DUMP_VHOSTS")) {
        apr_file_t *thefile = NULL;
        apr_file_open_stderr(&thefile, p);
        dump_vhost_config(thefile);
    }
}