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server.c
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server.c
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/*
* NNTPSwitch Server Configuration
*
* $Id: server.c,v 1.20 2011-02-16 07:21:08 tommy Exp $
*/
#include "aconfig.h"
#include "nntpd.h"
#include "memory.h"
#include "aprotos.h"
int linenr;
char lastgroups[MAX_CFGLINE];
int lastlevel;
/* sort function */
int cmp_server_level(const void *a, const void *b)
{
const SERVER *s1 = *((const SERVER **) a);
const SERVER *s2 = *((const SERVER **) b);
if ( s1->Level > s2->Level )
return -1;
if ( s1->Level < s2->Level )
return 1;
return 0;
}
PROTO void clear_servers(void)
{
master->numservers = 0;
}
PROTO void reload_servers(void)
{
struct stat _stat;
if ( stat(cfg.ServerFile, &_stat) == -1 )
die("Can't stat server config file %s", cfg.ServerFile);
if ( master->laststatserver < _stat.st_mtime )
{
clear_servers();
load_servers();
}
}
PROTO void load_servers(void)
{
FILE *f;
struct stat _stat;
char buf[MAX_CFGLINE];
SERVER *def;
int i,s;
if ( (f=fopen(cfg.ServerFile,"r")) == NULL )
die("Can't open server config %s", cfg.ServerFile);
linenr = 0;
lastgroups[0] = 0;
lastlevel = 0;
while( fgets(buf, MAX_CFGLINE, f) )
{
chop(buf);
linenr++;
if ( buf[0] == ';' || buf[0] == '#' || buf[0] == 0 )
continue;
if ( strncasecmp(buf, "server", 6) == 0 )
parsecfg_server(buf,f);
else
die("Syntax error in %s on line %d", cfg.ServerFile, linenr);
}
fclose(f);
def = getserver("default");
if ( def == NULL )
die("Server \"default\" not defined");
/* Sort the servers by level which we'll use later */
s=0;
for (i=0; i<master->numservers; i++ )
if ( (master->servers+i) != def )
master->lservers[s++] = (master->servers+i);
qsort(master->lservers, master->numservers-1, sizeof(SERVER*), cmp_server_level);
stat(cfg.ServerFile,&_stat);
master->laststatserver = _stat.st_mtime;
/* clear the balance position list */
for ( i=0; i< MAX_LEVEL; i++ )
master->balance_pos[i] = 0;
check_server_redundancy();
info("Loaded %d Servers", master->numservers);
}
PROTO void parsecfg_server(char *buf, FILE *f)
{
char key[64], val[MAX_CFGLINE];
int i;
SERVER *def;
if ( (sscanf(buf, "%s %s", key, val)) != 2 )
die("Server Syntax error on line %d of %s", linenr, cfg.ServerFile);
/* Some basic initialization */
(master->servers+master->numservers)->MaxConnections = 0;
if ( strcmp(val, "default") != 0 )
{
/* we inherit (copy) from default server */
if ( (def = getserver("default")) == NULL )
die("Could not retrieve default server, the default server must be listed first.");
memcpy((master->servers+master->numservers), def, sizeof(SERVER));
}
strcpy((master->servers+master->numservers)->Name, val);
if ( getserver(val) != NULL )
die("Servername \"%s\" already defined online %d of %s", val, linenr, cfg.ServerFile);
i=0;
while( !i && fgets(buf, MAX_CFGLINE, f) )
{
chop(buf);
linenr++;
if ( buf[0] == ';' || buf[0] == '#' || buf[0] == 0 )
continue;
if ( strncasecmp(buf, "end", 3) == 0 )
{
i++;
break;
}
if ( sscanf(buf, "%*[ \t]%64s%*[ \t]%16384s[^\r\n]%*[\t\r\n]", key, val) != 2 )
die("Error on line %d of %s (%s - %s)", linenr, cfg.ServerFile, key, val);
/* start scanning parameters */
if ( strcasecmp(key, "hostname") == 0 )
strcpy((master->servers+master->numservers)->Hostname, val);
else
if ( strcasecmp(key, "groups") == 0 )
{
if ( lastgroups == NULL || strcmp(lastgroups, val) )
{
strcpy(lastgroups, val);
lastlevel ++;
}
strcpy((master->servers+master->numservers)->Groups, val);
(master->servers+master->numservers)->Level = lastlevel;
}
else
if ( strcasecmp(key, "Username") == 0 )
strcpy((master->servers+master->numservers)->Username, val);
else
if ( strcasecmp(key, "Password") == 0 )
strcpy((master->servers+master->numservers)->Password, val);
else
if ( strcasecmp(key, "timeout") == 0 )
(master->servers+master->numservers)->Timeout = atoi(val);
else
if ( strcasecmp(key, "port") == 0 )
(master->servers+master->numservers)->Port = atoi(val);
else
if ( strcasecmp(key, "maxconnections") == 0 )
(master->servers+master->numservers)->MaxConnections = atoi(val);
else
if ( strcasecmp(key, "type") == 0 )
{
if ( strcasecmp(val, "spool") == 0 )
(master->servers+master->numservers)->ServerType = type_spool;
else
if ( strcasecmp(val, "xover") == 0 )
(master->servers+master->numservers)->ServerType = type_xover;
else
if ( strcasecmp(val, "post") == 0 )
(master->servers+master->numservers)->ServerType = type_post;
else
die("Unknown server type on line %d of %s", linenr, cfg.ServerFile);
}
else
if ( strcasecmp(key, "policy") == 0 )
{
if ( strcasecmp(val, "single") == 0 )
(master->servers+master->numservers)->Policy = policy_single;
else
if ( strcasecmp(val, "backup") == 0 )
(master->servers+master->numservers)->Policy = policy_backup;
else
if ( strcasecmp(val, "balance") == 0 )
(master->servers+master->numservers)->Policy = policy_balance;
else
die("Unknown server policy on line %d of %s", linenr, cfg.ServerFile);
}
else
if ( strcasecmp(key, "activetimes") == 0 )
{
if ( strcasecmp(val, "false") == 0 )
(master->servers+master->numservers)->ActiveTimes = 0;
else
if ( strcasecmp(val, "true") == 0 )
(master->servers+master->numservers)->ActiveTimes = 1;
else
(master->servers+master->numservers)->ActiveTimes = atoi(val);
}
else
if ( strcasecmp(key, "descriptions") == 0 )
{
if ( strcasecmp(val, "false") == 0 )
(master->servers+master->numservers)->Descriptions = 0;
else
if ( strcasecmp(val, "true") == 0 )
(master->servers+master->numservers)->Descriptions = 1;
else
(master->servers+master->numservers)->Descriptions = atoi(val);
}
else
if ( strcasecmp(key, "splitlist") == 0 )
{
if ( strcasecmp(val, "false") == 0 )
(master->servers+master->numservers)->SplitList = 0;
else
if ( strcasecmp(val, "true") == 0 )
(master->servers+master->numservers)->SplitList = 1;
else
(master->servers+master->numservers)->SplitList = atoi(val);
}
else
info("Unknown servers.conf option: %s %s", key, val);
}
master->numservers++;
}
PROTO SERVER* getserver(const char *name)
{
int i;
for (i=0; i<master->numservers; i++)
if ( strcmp((master->servers+i)->Name, name) == 0 )
return (master->servers+i);
return NULL;
}
/*
* count the number of servers with the same level as us
*/
int count_server_level(int level)
{
int i;
int num = 0;
for (i=0; i<master->numservers; i++)
if ( (master->servers+i)->Level == level )
num++;
return num;
}
/*
* Increase the current server number
*/
void add_level_usage(int lv)
{
int max = count_server_level(lv);
/* roll the number */
master->balance_pos[lv]++;
if ( master->balance_pos[lv] >= max )
master->balance_pos[lv] = 0;
}
/*
* get the next server from the list
*/
SERVER * get_next_server(int lv)
{
int i, num;
/* otherwise we have to pick one according to the balancer */
num = master->balance_pos[lv];
for (i=0; i<master->numservers-1; i++)
{
if ( master->lservers[i]->Level == lv )
{
if ( num == 0 )
{
add_level_usage(lv);
uint max = master->lservers[i]->MaxConnections;
uint cur = master->lservers[i]->connections;
if ( max != 0 && cur >= max )
return get_next_server(lv);
return master->lservers[i];
}
num--;
}
}
return NULL;
}
/*
* select first server based on some servername
*/
PROTO SERVER* selectserver_primary(const char *name)
{
SERVER *s;
s = getserver(name);
if ( (int)s->connections < 0 ) {
syslog(LOG_NOTICE, "Server %s has < 0 connections (%d)", s->Name, s->connections);
}
/* in case of backup scheme, check for maxconnections on server */
if ( s->Policy == policy_backup && (s->MaxConnections != 0 && s->connections >= s->MaxConnections) )
return get_next_server(s->Level);
/* single or backup policy's just pick the first server */
if ( s == NULL || s->Policy == policy_single || s->Policy == policy_backup )
return s;
s = get_next_server(s->Level);
if ( s == NULL )
syslog(LOG_DEBUG, "Hmm, could not find the other balancing server for %s", name);
return s;
}
/*
* Find the next server with the same level. This most likely
* is a backup servers. Give backup servers the same level
* in the servers.conf.
*/
PROTO SERVER* selectserver_backup(SERVER *current, SERVER *primary)
{
SERVER *s;
/* dont check single server policies */
if ( current == NULL || current->Policy == policy_single )
return NULL;
s = get_next_server(primary->Level);
/* too bad, no backup server */
if ( s == NULL )
syslog(LOG_DEBUG, "No next server for policy in %s", current->Name);
return s;
}
/*
* Connect to a backend server taking the backup and balancing
* policies in account. Return false on some error, true on
* success.
*/
PROTO int connect_groupserver(CLIENT *cl, char *server)
{
SERVER *svr, *primary;
svr = getserver(server);
if ( cl->connected == 1 && strcmp(cl->groupserver->Groups, svr->Groups) == 0 )
return CONNECT_OK;
/* disconnect first if we have to change server */
if ( cl->connected == 1 && strcmp(cl->groupserver->Name, server) != 0 )
disconnect_server(cl);
if ( cl->connected != 1 )
{
/* Get the real server and take balancing stuff in account */
if ( (svr=selectserver_primary(server)) == NULL )
return CONNECT_ERR;
primary = svr; /* remember where we started with */
cl->groupserver = svr;
if ( connect_server(cl, svr) )
{
if ( errno )
errno = 0;
/* On server down find backup servers and try to conect to them */
while( cl->connected != 1 && (svr = selectserver_backup(cl->groupserver, primary)) != NULL )
{
cl->groupserver = svr;
if ( connect_server(cl, svr) )
if ( errno )
errno = 0;
}
if ( cl->connected != 1 )
{
cl->group = NULL;
cl->groupserver = NULL;
return CONNECT_DOWN;
}
}
}
return CONNECT_OK;
}
/*
* Check if servers configured with backup actually do have a backup server configured.
*/
PROTO void check_server_redundancy(void)
{
int i;
SERVER *s;
int lev = -1;
for (i=0; i<master->numservers-1; i++)
{
if ( master->lservers[i]->Level == lev )
continue;
if ( master->lservers[i]->Policy == policy_backup
|| master->lservers[i]->Policy == policy_balance )
{
lev = master->lservers[i]->Level;
info("Checking server: %s", master->lservers[i]->Name);
add_level_usage(lev);
s = get_next_server( master->lservers[i]->Level );
if ( s == NULL || s == master->lservers[i] ) {
die("Configuration error, no secondary server found, for server %s", master->lservers[i]->Name);
}
}
}
}