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/*
* PgBouncer - Lightweight connection pooler for PostgreSQL.
*
* Copyright (c) 2007-2009 Marko Kreen, Skype Technologies OÜ
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Handling of server connections
*/
#include "bouncer.h"
static bool load_parameter(PgSocket *server, PktHdr *pkt, bool startup)
{
const char *key, *val;
PgSocket *client = server->link;
/*
* Want to see complete packet. That means SMALL_PKT
* in sbuf.c must be larger than max param pkt.
*/
if (incomplete_pkt(pkt))
return false;
key = mbuf_get_string(&pkt->data);
val = mbuf_get_string(&pkt->data);
if (!key || !val) {
disconnect_server(server, true, "broken ParameterStatus packet");
return false;
}
slog_debug(server, "S: param: %s = %s", key, val);
varcache_set(&server->vars, key, val);
if (client) {
slog_debug(client, "setting client var: %s='%s'", key, val);
varcache_set(&client->vars, key, val);
}
if (startup)
add_welcome_parameter(server->pool, key, val);
return true;
}
/* we cannot log in at all, notify clients */
static void kill_pool_logins(PgPool *pool, PktHdr *errpkt)
{
List *item, *tmp;
PgSocket *client;
const char *level, *msg;
parse_server_error(errpkt, &level, &msg);
log_warning("server login failed: %s %s", level, msg);
statlist_for_each_safe(item, &pool->waiting_client_list, tmp) {
client = container_of(item, PgSocket, head);
if (!client->wait_for_welcome)
continue;
disconnect_client(client, true, msg);
}
}
/* process packets on server auth phase */
static bool handle_server_startup(PgSocket *server, PktHdr *pkt)
{
SBuf *sbuf = &server->sbuf;
bool res = false;
if (incomplete_pkt(pkt)) {
disconnect_server(server, true, "partial pkt in login phase");
return false;
}
/* ignore most that happens during connect_query */
if (server->exec_on_connect) {
switch (pkt->type) {
case 'Z':
case 'S': /* handle them below */
break;
case 'E': /* log & ignore errors */
log_server_error("S: error while executing exec_on_query", pkt);
default: /* ignore rest */
sbuf_prepare_skip(sbuf, pkt->len);
return true;
}
}
switch (pkt->type) {
default:
slog_error(server, "unknown pkt from server: '%c'", pkt_desc(pkt));
disconnect_server(server, true, "unknown pkt from server");
break;
case 'E': /* ErrorResponse */
if (!server->pool->welcome_msg_ready)
kill_pool_logins(server->pool, pkt);
else
log_server_error("S: login failed", pkt);
disconnect_server(server, true, "login failed");
break;
/* packets that need closer look */
case 'R': /* AuthenticationXXX */
slog_debug(server, "calling login_answer");
res = answer_authreq(server, pkt);
if (!res)
disconnect_server(server, false, "failed to answer authreq");
break;
case 'S': /* ParameterStatus */
res = load_parameter(server, pkt, true);
break;
case 'Z': /* ReadyForQuery */
if (server->exec_on_connect) {
server->exec_on_connect = 0;
/* deliberately ignore transaction status */
} else if (server->pool->db->connect_query) {
server->exec_on_connect = 1;
slog_debug(server, "server conect ok, send exec_on_connect");
SEND_generic(res, server, 'Q', "s", server->pool->db->connect_query);
if (!res)
disconnect_server(server, false, "exec_on_connect query failed");
break;
}
/* login ok */
slog_debug(server, "server login ok, start accepting queries");
server->ready = 1;
/* got all params */
finish_welcome_msg(server);
/* need to notify sbuf if server was closed */
res = release_server(server);
/* let the takeover process handle it */
if (res && server->pool->db->admin)
res = takeover_login(server);
break;
/* ignorable packets */
case 'K': /* BackendKeyData */
if (mbuf_avail(&pkt->data) >= BACKENDKEY_LEN)
memcpy(server->cancel_key,
mbuf_get_bytes(&pkt->data, BACKENDKEY_LEN),
BACKENDKEY_LEN);
res = true;
break;
case 'N': /* NoticeResponse */
slog_noise(server, "skipping pkt: %c", pkt_desc(pkt));
res = true;
break;
}
if (res)
sbuf_prepare_skip(sbuf, pkt->len);
return res;
}
/* process packets on logged in connection */
static bool handle_server_work(PgSocket *server, PktHdr *pkt)
{
bool ready = 0;
char state;
SBuf *sbuf = &server->sbuf;
PgSocket *client = server->link;
Assert(!server->pool->db->admin);
switch (pkt->type) {
default:
slog_error(server, "unknown pkt: '%c'", pkt_desc(pkt));
disconnect_server(server, true, "unknown pkt");
return false;
/* pooling decisions will be based on this packet */
case 'Z': /* ReadyForQuery */
/* if partial pkt, wait */
if (mbuf_avail(&pkt->data) == 0)
return false;
state = mbuf_get_char(&pkt->data);
/* set ready only if no tx */
if (state == 'I')
ready = 1;
else if (cf_pool_mode == POOL_STMT) {
disconnect_server(server, true,
"Long transactions not allowed");
return false;
}
break;
case 'S': /* ParameterStatus */
if (!load_parameter(server, pkt, false))
return false;
break;
/*
* 'E' and 'N' packets currently set ->ready to 0. Correct would
* be to leave ->ready as-is, because overal TX state stays same.
* It matters for connections in IDLE or USED state which get dirty
* suddenly but should not as they are still usable.
*
* But the 'E' or 'N' packet between transactions signifies probably
* dying backend. This its better to tag server as dirty and drop
* it later.
*/
case 'E': /* ErrorResponse */
if (server->setting_vars) {
/*
* the SET and user query will be different TX
* so we cannot report SET error to user.
*/
log_server_error("varcache_apply failed", pkt);
/*
* client probably gave invalid values in startup pkt.
*
* no reason to keep such guys.
*/
disconnect_server(server, true, "invalid server parameter");
return false;
}
case 'N': /* NoticeResponse */
break;
/* chat packets */
case '2': /* BindComplete */
case '3': /* CloseComplete */
case 'c': /* CopyDone(F/B) */
case 'f': /* CopyFail(F/B) */
case 'I': /* EmptyQueryResponse == CommandComplete */
case 'V': /* FunctionCallResponse */
case 'n': /* NoData */
case 'G': /* CopyInResponse */
case 'H': /* CopyOutResponse */
case '1': /* ParseComplete */
case 'A': /* NotificationResponse */
case 's': /* PortalSuspended */
case 'C': /* CommandComplete */
/* data packets, there will be more coming */
case 'd': /* CopyData(F/B) */
case 'D': /* DataRow */
case 't': /* ParameterDescription */
case 'T': /* RowDescription */
break;
}
server->ready = ready;
server->pool->stats.server_bytes += pkt->len;
if (server->setting_vars) {
Assert(client);
sbuf_prepare_skip(sbuf, pkt->len);
} else if (client) {
sbuf_prepare_send(sbuf, &client->sbuf, pkt->len);
if (ready && client->query_start) {
usec_t total;
total = get_cached_time() - client->query_start;
client->query_start = 0;
server->pool->stats.query_time += total;
slog_debug(client, "query time: %d us", (int)total);
} else if (ready) {
slog_warning(client, "FIXME: query end, but query_start == 0");
}
} else {
if (server->state != SV_TESTED)
slog_warning(server,
"got packet '%c' from server when not linked",
pkt_desc(pkt));
sbuf_prepare_skip(sbuf, pkt->len);
}
return true;
}
/* got connection, decide what to do */
static bool handle_connect(PgSocket *server)
{
bool res = false;
PgPool *pool = server->pool;
fill_local_addr(server, sbuf_socket(&server->sbuf), server->remote_addr.is_unix);
if (!statlist_empty(&pool->cancel_req_list)) {
slog_debug(server, "use it for pending cancel req");
/* if pending cancel req, send it */
forward_cancel_request(server);
/* notify disconnect_server() that connect did not fail */
server->ready = 1;
disconnect_server(server, false, "sent cancel req");
} else {
/* proceed with login */
res = send_startup_packet(server);
if (!res)
disconnect_server(server, false, "startup pkt failed");
}
return res;
}
/* callback from SBuf */
bool server_proto(SBuf *sbuf, SBufEvent evtype, MBuf *data)
{
bool res = false;
PgSocket *server = container_of(sbuf, PgSocket, sbuf);
PgPool *pool = server->pool;
PktHdr pkt;
Assert(is_server_socket(server));
Assert(server->state != SV_FREE);
/* may happen if close failed */
if (server->state == SV_JUSTFREE)
return false;
switch (evtype) {
case SBUF_EV_RECV_FAILED:
disconnect_server(server, false, "server conn crashed?");
break;
case SBUF_EV_SEND_FAILED:
disconnect_client(server->link, false, "unexpected eof");
break;
case SBUF_EV_READ:
if (mbuf_avail(data) < NEW_HEADER_LEN) {
slog_noise(server, "S: got partial header, trying to wait a bit");
break;
}
/* parse pkt header */
if (!get_header(data, &pkt)) {
disconnect_server(server, true, "bad pkt header");
break;
}
slog_noise(server, "S: pkt '%c', len=%d", pkt_desc(&pkt), pkt.len);
server->request_time = get_cached_time();
switch (server->state) {
case SV_LOGIN:
res = handle_server_startup(server, &pkt);
break;
case SV_TESTED:
case SV_USED:
case SV_ACTIVE:
case SV_IDLE:
res = handle_server_work(server, &pkt);
break;
default:
fatal("server_proto: server in bad state: %d", server->state);
}
break;
case SBUF_EV_CONNECT_FAILED:
Assert(server->state == SV_LOGIN);
disconnect_server(server, false, "connect failed");
break;
case SBUF_EV_CONNECT_OK:
slog_debug(server, "S: connect ok");
Assert(server->state == SV_LOGIN);
server->request_time = get_cached_time();
res = handle_connect(server);
break;
case SBUF_EV_FLUSH:
res = true;
if (!server->ready)
break;
if (server->setting_vars) {
PgSocket *client = server->link;
Assert(client);
server->setting_vars = 0;
sbuf_continue(&client->sbuf);
break;
}
if (cf_pool_mode != POOL_SESSION || server->state == SV_TESTED) {
switch (server->state) {
case SV_ACTIVE:
case SV_TESTED:
/* retval does not matter here */
release_server(server);
break;
default:
slog_warning(server, "EV_FLUSH with state=%d", server->state);
case SV_IDLE:
break;
}
}
break;
case SBUF_EV_PKT_CALLBACK:
slog_warning(server, "SBUF_EV_PKT_CALLBACK with state=%d", server->state);
break;
}
if (!res && pool->db->admin)
takeover_login_failed();
return res;
}
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