/* writes <len> bytes from message <msg> to the channel's buffer. Returns -1 in
* case of success, -2 if the message is larger than the buffer size, or the
* number of bytes available otherwise. The send limit is automatically
* adjusted to the amount of data written. FIXME-20060521: handle unaligned
* data. Note: this function appends data to the buffer's output and possibly
* overwrites any pending input data which are assumed not to exist.
*/
int bo_inject(struct channel *chn, const char *msg, int len)
{
int max;
if (len == 0)
return -1;
if (len > chn->buf->size) {
/* we can't write this chunk and will never be able to, because
* it is larger than the buffer. This must be reported as an
* error. Then we return -2 so that writers that don't care can
* ignore it and go on, and others can check for this value.
*/
return -2;
}
max = buffer_realign(chn->buf);
if (len > max)
return max;
memcpy(chn->buf->p, msg, len);
chn->buf->o += len;
chn->buf->p = b_ptr(chn->buf, len);
chn->total += len;
return -1;
}
int assign_server(struct session *s)
{
struct connection *conn;
struct server *conn_slot;
struct server *srv, *prev_srv;
int err;
DPRINTF(stderr,"assign_server : s=%p\n",s);
err = SRV_STATUS_INTERNAL;
if (unlikely(s->pend_pos || s->flags & SN_ASSIGNED))
goto out_err;
prev_srv = objt_server(s->target);
conn_slot = s->srv_conn;
/* We have to release any connection slot before applying any LB algo,
* otherwise we may erroneously end up with no available slot.
*/
if (conn_slot)
sess_change_server(s, NULL);
/* We will now try to find the good server and store it into <objt_server(s->target)>.
* Note that <objt_server(s->target)> may be NULL in case of dispatch or proxy mode,
* as well as if no server is available (check error code).
*/
srv = NULL;
s->target = NULL;
conn = objt_conn(s->si[1].end);
if (conn &&
(conn->flags & CO_FL_CONNECTED) &&
objt_server(conn->target) && __objt_server(conn->target)->proxy == s->be &&
((s->txn.flags & TX_PREFER_LAST) ||
((s->be->options & PR_O_PREF_LAST) &&
(!s->be->max_ka_queue ||
server_has_room(__objt_server(conn->target)) ||
(__objt_server(conn->target)->nbpend + 1) < s->be->max_ka_queue))) &&
srv_is_usable(__objt_server(conn->target))) {
/* This session was relying on a server in a previous request
* and the proxy has "option prefer-last-server" set, so
* let's try to reuse the same server.
*/
srv = __objt_server(conn->target);
s->target = &srv->obj_type;
}
else if (s->be->lbprm.algo & BE_LB_KIND) {
/* we must check if we have at least one server available */
if (!s->be->lbprm.tot_weight) {
err = SRV_STATUS_NOSRV;
goto out;
}
/* First check whether we need to fetch some data or simply call
* the LB lookup function. Only the hashing functions will need
* some input data in fact, and will support multiple algorithms.
*/
switch (s->be->lbprm.algo & BE_LB_LKUP) {
case BE_LB_LKUP_RRTREE:
srv = fwrr_get_next_server(s->be, prev_srv);
break;
case BE_LB_LKUP_FSTREE:
srv = fas_get_next_server(s->be, prev_srv);
break;
case BE_LB_LKUP_LCTREE:
srv = fwlc_get_next_server(s->be, prev_srv);
break;
case BE_LB_LKUP_CHTREE:
case BE_LB_LKUP_MAP:
if ((s->be->lbprm.algo & BE_LB_KIND) == BE_LB_KIND_RR) {
if (s->be->lbprm.algo & BE_LB_LKUP_CHTREE)
srv = chash_get_next_server(s->be, prev_srv);
else
srv = map_get_server_rr(s->be, prev_srv);
break;
}
else if ((s->be->lbprm.algo & BE_LB_KIND) != BE_LB_KIND_HI) {
/* unknown balancing algorithm */
err = SRV_STATUS_INTERNAL;
goto out;
}
switch (s->be->lbprm.algo & BE_LB_PARM) {
case BE_LB_HASH_SRC:
conn = objt_conn(s->si[0].end);
if (conn && conn->addr.from.ss_family == AF_INET) {
srv = get_server_sh(s->be,
(void *)&((struct sockaddr_in *)&conn->addr.from)->sin_addr,
4);
}
else if (conn && conn->addr.from.ss_family == AF_INET6) {
srv = get_server_sh(s->be,
(void *)&((struct sockaddr_in6 *)&conn->addr.from)->sin6_addr,
16);
}
else {
/* unknown IP family */
err = SRV_STATUS_INTERNAL;
goto out;
}
break;
case BE_LB_HASH_URI:
/* URI hashing */
if (s->txn.req.msg_state < HTTP_MSG_BODY)
break;
srv = get_server_uh(s->be,
b_ptr(s->req.buf, -http_uri_rewind(&s->txn.req)),
s->txn.req.sl.rq.u_l);
break;
case BE_LB_HASH_PRM:
/* URL Parameter hashing */
if (s->txn.req.msg_state < HTTP_MSG_BODY)
break;
srv = get_server_ph(s->be,
b_ptr(s->req.buf, -http_uri_rewind(&s->txn.req)),
s->txn.req.sl.rq.u_l);
if (!srv && s->txn.meth == HTTP_METH_POST)
srv = get_server_ph_post(s);
break;
case BE_LB_HASH_HDR:
/* Header Parameter hashing */
if (s->txn.req.msg_state < HTTP_MSG_BODY)
break;
srv = get_server_hh(s);
break;
case BE_LB_HASH_RDP:
/* RDP Cookie hashing */
srv = get_server_rch(s);
break;
default:
/* unknown balancing algorithm */
err = SRV_STATUS_INTERNAL;
goto out;
}
/* If the hashing parameter was not found, let's fall
* back to round robin on the map.
*/
if (!srv) {
if (s->be->lbprm.algo & BE_LB_LKUP_CHTREE)
srv = chash_get_next_server(s->be, prev_srv);
else
srv = map_get_server_rr(s->be, prev_srv);
}
/* end of map-based LB */
break;
default:
/* unknown balancing algorithm */
err = SRV_STATUS_INTERNAL;
goto out;
}
if (!srv) {
err = SRV_STATUS_FULL;
goto out;
}
else if (srv != prev_srv) {
s->be->be_counters.cum_lbconn++;
srv->counters.cum_lbconn++;
}
s->target = &srv->obj_type;
}
else if (s->be->options & (PR_O_DISPATCH | PR_O_TRANSP)) {
s->target = &s->be->obj_type;
}
else if ((s->be->options & PR_O_HTTP_PROXY) &&
(conn = objt_conn(s->si[1].end)) &&
is_addr(&conn->addr.to)) {
/* in proxy mode, we need a valid destination address */
s->target = &s->be->obj_type;
}
else {
err = SRV_STATUS_NOSRV;
goto out;
}
s->flags |= SN_ASSIGNED;
err = SRV_STATUS_OK;
out:
/* Either we take back our connection slot, or we offer it to someone
* else if we don't need it anymore.
*/
if (conn_slot) {
if (conn_slot == srv) {
sess_change_server(s, srv);
} else {
if (may_dequeue_tasks(conn_slot, s->be))
process_srv_queue(conn_slot);
}
}
out_err:
return err;
}
/*
* This function tries to find a running server for the proxy <px> following
* the Header parameter hash method. It looks for a specific parameter in the
* URL and hashes it to compute the server ID. This is useful to optimize
* performance by avoiding bounces between servers in contexts where sessions
* are shared but cookies are not usable. If the parameter is not found, NULL
* is returned. If any server is found, it will be returned. If no valid server
* is found, NULL is returned.
*/
struct server *get_server_hh(struct session *s)
{
unsigned int hash = 0;
struct http_txn *txn = &s->txn;
struct proxy *px = s->be;
unsigned int plen = px->hh_len;
unsigned long len;
struct hdr_ctx ctx;
const char *p;
const char *start, *end;
/* tot_weight appears to mean srv_count */
if (px->lbprm.tot_weight == 0)
return NULL;
ctx.idx = 0;
/* if the message is chunked, we skip the chunk size, but use the value as len */
http_find_header2(px->hh_name, plen, b_ptr(s->req.buf, -http_hdr_rewind(&txn->req)), &txn->hdr_idx, &ctx);
/* if the header is not found or empty, let's fallback to round robin */
if (!ctx.idx || !ctx.vlen)
return NULL;
/* note: we won't hash if there's only one server left */
if (px->lbprm.tot_used == 1)
goto hash_done;
/* Found a the hh_name in the headers.
* we will compute the hash based on this value ctx.val.
*/
len = ctx.vlen;
p = (char *)ctx.line + ctx.val;
if (!px->hh_match_domain) {
hash = gen_hash(px, p, len);
} else {
int dohash = 0;
p += len;
/* special computation, use only main domain name, not tld/host
* going back from the end of string, start hashing at first
* dot stop at next.
* This is designed to work with the 'Host' header, and requires
* a special option to activate this.
*/
end = p;
while (len) {
if (dohash) {
/* Rewind the pointer until the previous char
* is a dot, this will allow to set the start
* position of the domain. */
if (*(p - 1) == '.')
break;
}
else if (*p == '.') {
/* The pointer is rewinded to the dot before the
* tld, we memorize the end of the domain and
* can enter the domain processing. */
end = p;
dohash = 1;
}
p--;
len--;
}
start = p;
hash = gen_hash(px, start, (end - start));
}
if ((px->lbprm.algo & BE_LB_HASH_MOD) == BE_LB_HMOD_AVAL)
hash = full_hash(hash);
hash_done:
if (px->lbprm.algo & BE_LB_LKUP_CHTREE)
return chash_get_server_hash(px, hash);
else
return map_get_server_hash(px, hash);
}
/*
* this does the same as the previous server_ph, but check the body contents
*/
struct server *get_server_ph_post(struct session *s)
{
unsigned int hash = 0;
struct http_txn *txn = &s->txn;
struct channel *req = &s->req;
struct http_msg *msg = &txn->req;
struct proxy *px = s->be;
unsigned int plen = px->url_param_len;
unsigned long len = http_body_bytes(msg);
const char *params = b_ptr(req->buf, -http_data_rewind(msg));
const char *p = params;
const char *start, *end;
if (len == 0)
return NULL;
if (px->lbprm.tot_weight == 0)
return NULL;
while (len > plen) {
/* Look for the parameter name followed by an equal symbol */
if (params[plen] == '=') {
if (memcmp(params, px->url_param_name, plen) == 0) {
/* OK, we have the parameter here at <params>, and
* the value after the equal sign, at <p>
* skip the equal symbol
*/
p += plen + 1;
start = end = p;
len -= plen + 1;
while (len && *end != '&') {
if (unlikely(!HTTP_IS_TOKEN(*p))) {
/* if in a POST, body must be URI encoded or it's not a URI.
* Do not interpret any possible binary data as a parameter.
*/
if (likely(HTTP_IS_LWS(*p))) /* eol, uncertain uri len */
break;
return NULL; /* oh, no; this is not uri-encoded.
* This body does not contain parameters.
*/
}
len--;
end++;
/* should we break if vlen exceeds limit? */
}
hash = gen_hash(px, start, (end - start));
if ((px->lbprm.algo & BE_LB_HASH_MOD) == BE_LB_HMOD_AVAL)
hash = full_hash(hash);
if (px->lbprm.algo & BE_LB_LKUP_CHTREE)
return chash_get_server_hash(px, hash);
else
return map_get_server_hash(px, hash);
}
}
/* skip to next parameter */
p = memchr(params, '&', len);
if (!p)
return NULL;
p++;
len -= (p - params);
params = p;
}
return NULL;
}
int main(void) {
Ptr<D> d_ptr;
Ptr<B> b_ptr(d_ptr); // Now supported
b_ptr = d_ptr; // Now supported
return 0;
}
