const char* DBLB_GetServer(const char* lb_name,
TDBLB_Flags flags,
const SDBLB_Preference* preference,
const char* const skip_servers[],
SDBLB_ConnPoint* conn_point,
char* server_name_buf,
size_t server_name_buflen,
EDBLB_Status* result)
{
static const char kPrefix[] = "DB_IP__";
size_t len, n, a_skip, n_skip;
SConnNetInfo* net_info;
int/*bool*/ failed;
unsigned int x_host;
unsigned short x_port;
double x_pref;
SSERV_InfoCPtr* skip;
SSERV_Info* info;
SDBLB_ConnPoint cp;
EDBLB_Status x;
const char* c;
if (!result)
result = &x;
if (server_name_buf) {
assert(server_name_buflen);
server_name_buf[0] = '\0';
}
if (!conn_point)
conn_point = &cp;
memset(conn_point, 0, sizeof(*conn_point));
if (!lb_name || !*lb_name) {
*result = eDBLB_BadName;
return 0/*failure*/;
}
*result = eDBLB_Success;
if (strchr(lb_name, '.')) {
cp.host = SOCK_gethostbyname(lb_name);
if (cp.host == SOCK_GetLoopbackAddress())
cp.host = /*FIXME?*/SERV_LOCALHOST;
} else
cp.host = 0;
skip = 0;
n_skip = 0;
a_skip = 0;
net_info = 0;
failed = 0/*false*/;
if (skip_servers) {
for (n = 0; !failed && skip_servers[n]; n++) {
const char* server = skip_servers[n];
SSERV_Info* info;
if (!(len = strlen(server))) {
continue;
}
if (strncasecmp(server, kPrefix, sizeof(kPrefix)-1) == 0
&& isdigit((unsigned char) server[sizeof(kPrefix)-1])) {
c = strstr(server + sizeof(kPrefix)-1, "__");
if (c) {
size_t i = (size_t)(c - server) - (sizeof(kPrefix)-1);
char* temp = strdup(server + sizeof(kPrefix)-1);
if (temp) {
char* s = temp + i;
*s++ = ':';
memmove(s, s + 1, strlen(s + 1) + 1);
server = temp;
while (++temp < s) {
if (*temp == '_')
*temp = '.';
}
len -= sizeof(kPrefix);
}
}
}
if (SOCK_StringToHostPort(server, &x_host, &x_port)
!= server + len) {
int/*bool*/ resolved = 0/*false*/;
const SSERV_Info* temp;
SERV_ITER iter;
if (!net_info)
net_info = ConnNetInfo_Create(lb_name);
iter = SERV_Open(skip_servers[n],
fSERV_Standalone | fSERV_Dns
| fSERV_Promiscuous,
0, net_info);
do {
SSERV_Info* dns;
temp = SERV_GetNextInfo(iter);
if (temp) {
x_host = temp->host;
if (x_host && s_IsSkipHost(x_host, cp.host)) {
failed = 1/*true*/;
break;
}
x_port = temp->port;
} else if (!resolved) {
x_host = 0;
x_port = 0;
} else
break;
if ((dns = SERV_CreateDnsInfo(x_host)) != 0) {
dns->port = x_port;
s_AddSkip(&skip, &a_skip, &n_skip, x_host
? dns
: SERV_CopyInfoEx(dns, skip_servers[n]));
if (!x_host)
free(dns);
}
resolved = 1/*true*/;
} while (temp);
SERV_Close(iter);
info = 0;
} else if (s_IsSkipHost(x_host, cp.host)) {
failed = 1/*true*/;
info = 0;
} else if (server != skip_servers[n]) {
info = SERV_CreateStandaloneInfo(x_host, x_port);
} else if ((info = SERV_CreateDnsInfo(x_host)) != 0)
info->port = x_port;
if (server != skip_servers[n])
free((void*) server);
if (info)
s_AddSkip(&skip, &a_skip, &n_skip, info);
}
}
if (!failed && !cp.host) {
if (preference) {
x_host = preference->host;
x_port = preference->port;
if ((x_pref = preference->pref) < 0.0)
x_pref = 0.0;
else if (x_pref >= 100.0)
x_pref = -1.0;
} else {
x_host = 0;
x_port = 0;
x_pref = 0.0;
}
if (!net_info)
net_info = ConnNetInfo_Create(lb_name);
info = SERV_GetInfoP(lb_name, fSERV_ReverseDns | fSERV_Standalone,
x_host, x_port, x_pref, net_info,
skip, n_skip, 0/*not external*/,
0, 0, 0); /* NCBI_FAKE_WARNING: GCC */
if (!info && (flags & fDBLB_AllowFallbackToStandby)) {
/*FIXME: eliminate second pass by fix in ordering in ncbi_lbsmd.c*/
info = SERV_GetInfoP(lb_name, fSERV_ReverseDns | fSERV_Standalone
| fSERV_IncludeSuppressed,
x_host, x_port, x_pref, net_info,
skip, n_skip, 0/*not external*/,
0, 0, 0); /* NCBI_FAKE_WARNING: GCC */
}
} else
info = 0;
if (!info) {
if (!failed) {
if (!cp.host) {
if (n_skip && (x_host = SOCK_gethostbyname(lb_name)) != 0) {
for (n = 0; n < n_skip; n++) {
if (x_host == skip[n]->host) {
failed = 1/*true*/;
break;
}
}
}
if (!failed && skip_servers) {
for (n = 0; (c = skip_servers[n]) != 0; n++) {
if (strcasecmp(c, lb_name) == 0) {
failed = 1/*true*/;
break;
}
}
}
} else if (conn_point != &cp) {
conn_point->host = cp.host;
conn_point->time = NCBI_TIME_INFINITE;
}
}
if (!failed && server_name_buf)
strncpy0(server_name_buf, lb_name, server_name_buflen - 1);
*result = eDBLB_NotFound;
} else {
if (info->type != fSERV_Dns) {
char* s, buf[80];
strncpy0(buf, kPrefix, sizeof(buf) - 1);
SOCK_HostPortToString(info->host, info->port,
buf + sizeof(kPrefix) - 1,
sizeof(buf) - sizeof(kPrefix));
len = strlen(buf);
if ((s = strchr(buf, ':')) != 0)
memmove(s + 1, s, strlen(s) + 1);
for (n = 0; n < len; n++) {
if (buf[n] == '.' || buf[n] == ':')
buf[n] = '_';
}
if (server_name_buf)
strncpy0(server_name_buf, buf, server_name_buflen - 1);
*result = eDBLB_NoDNSEntry;
} else if (info->host) {
c = SERV_NameOfInfo(info);
assert(c);
if (server_name_buf)
strncpy0(server_name_buf, c, server_name_buflen - 1);
} else {
failed = 1/*true*/;
*result = eDBLB_ServiceDown;
}
if (!failed) {
conn_point->host = info->host;
conn_point->port = info->port;
conn_point->time = info->time;
}
free(info);
}
for (n = 0; n < n_skip; n++)
free((void*) skip[n]);
if (skip)
free((void*) skip);
if (net_info)
ConnNetInfo_Destroy(net_info);
return failed ? 0 : (server_name_buf ? server_name_buf : lb_name);
}
SSERV_Info* SERV_CopyInfo(const SSERV_Info* orig)
{
return SERV_CopyInfoEx(orig, 0);
}
static SERV_ITER s_Open(const char* service,
unsigned/*bool*/ ismask,
TSERV_Type types,
unsigned int preferred_host,
unsigned short preferred_port,
double preference,
const SConnNetInfo* net_info,
const SSERV_InfoCPtr skip[],
size_t n_skip,
unsigned/*bool*/ external,
const char* arg,
const char* val,
SSERV_Info** info,
HOST_INFO* host_info)
{
int/*bool*/ do_lbsmd = -1/*unassigned*/, do_dispd = -1/*unassigned*/;
const SSERV_VTable* op;
SERV_ITER iter;
const char* s;
if (!(s = s_ServiceName(service, ismask, 0)))
return 0;
if (!(iter = (SERV_ITER) calloc(1, sizeof(*iter)))) {
free((void*) s);
return 0;
}
assert(ismask || *s);
iter->name = s;
iter->type = types & fSERV_All;
iter->host = (preferred_host == SERV_LOCALHOST
? SOCK_GetLocalHostAddress(eDefault)
: preferred_host);
iter->port = preferred_port;
iter->pref = (preference < 0.0
? -1.0
: 0.01 * (preference > 100.0
? 100.0
: preference));
if (ismask)
iter->ismask = 1;
if (types & fSERV_IncludeDown)
iter->ok_down = 1;
if (types & fSERV_IncludeSuppressed)
iter->ok_suppressed = 1;
if (types & fSERV_ReverseDns)
iter->reverse_dns = 1;
if (types & fSERV_Stateless)
iter->stateless = 1;
iter->external = external;
if (arg && *arg) {
iter->arg = arg;
iter->arglen = strlen(arg);
if (val) {
iter->val = val;
iter->vallen = strlen(val);
}
}
iter->time = (TNCBI_Time) time(0);
if (n_skip) {
size_t i;
for (i = 0; i < n_skip; i++) {
const char* name = (iter->ismask || skip[i]->type == fSERV_Dns
? SERV_NameOfInfo(skip[i]) : "");
SSERV_Info* temp = SERV_CopyInfoEx(skip[i],
!iter->reverse_dns || *name ?
name : s);
if (temp) {
temp->time = NCBI_TIME_INFINITE;
if (!s_AddSkipInfo(iter, name, temp)) {
free(temp);
temp = 0;
}
}
if (!temp) {
SERV_Close(iter);
return 0;
}
}
}
assert(n_skip == iter->n_skip);
if (net_info) {
if (net_info->firewall)
iter->type |= fSERV_Firewall;
if (net_info->stateless)
iter->stateless = 1;
if (net_info->lb_disable)
do_lbsmd = 0/*false*/;
} else
do_dispd = 0/*false*/;
/* Ugly optimization not to access the registry more than necessary */
if ((!s_IsMapperConfigured(service, REG_CONN_LOCAL_ENABLE) ||
!(op = SERV_LOCAL_Open(iter, info, host_info))) &&
(!do_lbsmd ||
!(do_lbsmd= !s_IsMapperConfigured(service, REG_CONN_LBSMD_DISABLE)) ||
!(op = SERV_LBSMD_Open(iter, info, host_info,
!do_dispd ||
!(do_dispd = !s_IsMapperConfigured
(service, REG_CONN_DISPD_DISABLE))))) &&
(!do_dispd ||
!(do_dispd= !s_IsMapperConfigured(service, REG_CONN_DISPD_DISABLE)) ||
!(op = SERV_DISPD_Open(iter, net_info, info, host_info)))) {
if (!do_lbsmd && !do_dispd) {
CORE_LOGF_X(1, eLOG_Error,
("[%s] No service mappers available", service));
}
SERV_Close(iter);
return 0;
}
assert(op != 0);
iter->op = op;
return iter;
}
static SSERV_Info* s_GetNextInfo(SERV_ITER iter, HOST_INFO* host_info)
{
const TSERV_Type types = iter->types & ~fSERV_Firewall;
size_t i, n, idx[eHost_NoMatch], n_cand, a_cand;
EHost_Match best_match, match;
struct SLBSM_Candidate* cand;
const SLBSM_Service* svc;
TNCBI_Time dns_info_time;
const SLBSM_Host* host;
const char* env, *a;
SSERV_Info* info;
const char* name;
double status;
int standby;
HEAP heap;
char* v;
heap = (HEAP)(iter->data != iter ? iter->data : 0);
if (heap) {
#ifdef LBSM_DEBUG
CORE_LOGF(eLOG_Trace,
("LBSM heap[%p, %p, %d] for \"%s\" detected",
heap, HEAP_Base(heap), HEAP_Serial(heap), iter->name));
#endif /*LBSM_DEBUG*/
/*noop*/;
} else if (!(heap = s_GetHeapCopy(iter->time))) {
return iter->external || iter->data == iter || !(types & fSERV_Dns)
? 0 : s_FakeDnsReturn(iter, host_info, 0, NCBI_TIME_INFINITE);
}
best_match = eHost_InitMatch;
memset(idx, 0, sizeof(idx));
standby = -1/*unassigned*/;
dns_info_time = 0/*none*/;
n = n_cand = a_cand = 0;
a = v = 0;
cand = 0;
svc = 0;
name = *iter->name ? iter->name : 0;
assert(name || iter->ismask); /*NB: ismask ignored for NULL*/
while ((svc = LBSM_LookupService(heap, name, iter->ismask, svc))) {
if (svc->entry.good < iter->time)
continue; /* out-of-date entry */
if (!svc->info.time)
continue; /* off */
if (types != fSERV_Any && !(types & svc->info.type))
continue; /* type doesn't match */
if (iter->external && svc->info.locl)
continue; /* external mapping requested; local/private server */
if (svc->info.locl & 0xF0) {
/* private server */
if (svc->info.host &&
svc->info.host != s_GetLocalHostAddress(heap)) {
continue;
}
}
if (svc->info.type == fSERV_Dns) {
if (types == fSERV_Any)
continue; /* DNS entries have to be requested explicitly */
if (!iter->ismask) {
if (dns_info_time < svc->info.time)
dns_info_time = svc->info.time;
}
} else {
if (iter->stateless && svc->info.sful) {
/* Skip stateful-only non-CGI (NCBID and standalone) svc */
if (!(svc->info.type & fSERV_Http))
continue;
}
if (!iter->ismask && iter->reverse_dns) {
if (dns_info_time < svc->info.time)
dns_info_time = svc->info.time;
}
}
if (svc->info.rate > 0.0 || host_info) {
if (!(host = s_LookupHost(heap, iter, svc))
&& svc->info.rate > 0.0) {
continue; /* no host information for non-static server */
}
} else
host = 0;
for (n = 0; n < iter->n_skip; n++) {
const SSERV_Info* skip = iter->skip[n];
const char* s = SERV_NameOfInfo(skip);
if (*s) {
assert(iter->ismask || iter->reverse_dns);
if (strcasecmp(s, (const char*) svc + svc->name) == 0
&& ((skip->type == fSERV_Dns && !skip->host)
|| SERV_EqualInfo(skip, &svc->info))) {
break;
}
} else if (SERV_EqualInfo(skip, &svc->info))
break;
if (skip->type == fSERV_Firewall
&& skip->u.firewall.type == svc->info.type) {
break;
}
if (iter->reverse_dns && skip->type == fSERV_Dns
&& skip->host == svc->info.host
&& (!skip->port || skip->port == svc->info.port)) {
break;
}
}
/*FIXME*//*CORE_LOG(eLOG_Note, (char*) svc + svc->name);*/
if (n >= iter->n_skip) {
status = LBSM_CalculateStatus(svc->info.rate, svc->fine,
svc->info.flag, &host->sys.load);
if (status <= 0.0) {
if (!svc->info.rate) {
if (!iter->ok_down)
continue; /* not operational */
status = 0.0;
} else
status = copysign(svc->info.rate, -1.0);
}
} else
status = 0.0; /* dummy assignment to keep no-init warning off */
if (v) {
free(v);
v = 0;
}
a = env = 0;
if (iter->pref < 0.0 && iter->host
&& (iter->host != svc->info.host
|| (iter->port && iter->port != svc->info.port))) {
/* not a suitable fixed latching */
match = eHost_BadMatch;
} else if (iter->arglen) {
assert(iter->arg);
if (!host)
host = s_LookupHost(heap, iter, svc);
if ( host && host->env)
env = (const char*) host + host->env;
match = s_Match(env,
iter->arg, iter->arglen,
iter->val, iter->vallen, &a, &v);
assert(!a || a == iter->arg);
} else
match = eHost_GoodMatch;
if (best_match > match)
best_match = match;
if (match > eHost_NoMatch) {
assert(!v);
continue;
}
if (svc->info.rate) {
/* NB: server is _not_ down, but it may have been suppressed */
if (fabs(svc->info.rate) < 0.01) {
if (!standby) {
if (!iter->ok_suppressed)
continue;
/* this has to be given out as a suppressed one */
status = copysign(svc->info.rate, -1.0);
} else if (standby < 0)
standby = 1;
} else if (standby) {
standby = 0/*cancel*/;
if (!iter->ok_suppressed) {
memset(idx, 0, sizeof(idx));
for (i = 0; i < n_cand; i++) {
if (cand[i].val)
free((void*) cand[i].val);
}
n_cand = 0;
} else for (i = 0; i < n_cand; i++)
cand[i].cand.status = copysign(cand[i].svc->info.rate,-1.);
}
}
if (n < iter->n_skip)
continue; /* excluded/seen; NB: dummy assignment goes off here */
if (!iter->ok_suppressed && status < 0.0)
continue;
#ifdef NCBI_LB_DEBUG
if (iter->arglen) {
char* s = SERV_WriteInfo(&svc->info);
const char* m;
assert(s);
switch (match) {
case eHost_BestMatch:
m = "Best match";
break;
case eHost_GoodMatch:
m = "Good match";
break;
case eHost_FairMatch:
m = "Fair match";
break;
case eHost_PoorMatch:
m = "Poor match";
break;
case eHost_NoMatch:
m = "No match";
break;
default:
assert(0);
m = "?";
break;
}
assert(!a || *a);
assert(!v || a);
CORE_LOGF(eLOG_Note, ("%s%s%s%s: %s%s%s%s%s%s", s,
env ? " <" : "", env ? env : "",
env ? ">" : "", m,
a ? ", arg=" : "",
a ? a : "",
v ? ", val=" : "",
v ? (*v ? v : "\"\"") : "",
standby > 0 ? ", standby" : ""));
free(s);
}
#endif /*NCBI_LB_DEBUG*/
/* This server should be taken into consideration */
if (n_cand == a_cand) {
struct SLBSM_Candidate* temp;
n = a_cand + 10;
temp = (struct SLBSM_Candidate*)
(cand
? realloc(cand, n * sizeof(*temp))
: malloc ( n * sizeof(*temp)));
if (!temp)
break;
cand = temp;
a_cand = n;
}
if (match < eHost_NoMatch) {
assert((size_t) match < sizeof(idx)/sizeof(idx[0]));
n = idx[match];
if (n < n_cand)
memmove(&cand[n + 1], &cand[n], sizeof(cand[0])*(n_cand - n));
for (i = match; i < sizeof(idx)/sizeof(idx[0]); i++)
idx[i]++;
} else
n = n_cand;
cand[n].cand.info = &svc->info;
cand[n].cand.status = status;
cand[n].host = host;
cand[n].svc = svc;
cand[n].arg = a;
cand[n].val = v;
a = v = 0;
n_cand++;
}
if (v)
free(v);
if (best_match < eHost_NoMatch) {
assert(!best_match || !idx[best_match - 1]);
for (n = idx[best_match]; n < n_cand; n++) {
if (cand[n].val)
free((void*) cand[n].val);
}
n_cand = idx[best_match];
}
if (n_cand) {
assert(cand);
do {
if (standby <= 0) {
struct SLBSM_Data data;
data.cand = cand;
data.n_cand = n_cand;
n = LB_Select(iter, &data, s_GetCandidate, LBSMD_LOCAL_BONUS);
} else {
qsort(cand, n_cand, sizeof(*cand), s_SortStandbys);
status = cand[0].cand.status;
for (n = 1; n < n_cand; n++) {
if (status != cand[n].cand.status)
break;
}
n = rand() % n;
}
svc = cand[n].svc;
if (iter->reverse_dns && svc->info.type != fSERV_Dns) {
svc = 0;
dns_info_time = 0/*none*/;
while ((svc = LBSM_LookupService(heap, 0/*all*/, 0, svc)) !=0){
if (svc->info.type != fSERV_Dns || !svc->info.time ||
svc->info.host != cand[n].svc->info.host ||
svc->info.port != cand[n].svc->info.port) {
continue;
}
if (!iter->ismask) {
if (dns_info_time < svc->info.time)
dns_info_time = svc->info.time;
}
if (iter->external && svc->info.locl)
continue;/* external mapping requested; local server */
assert(!(svc->info.locl & 0xF0)); /* no private DNS */
status = LBSM_CalculateStatus(!svc->info.rate ? 0.0
: -LBSM_DEFAULT_RATE,
svc->fine, fSERV_Regular,
NULL);
if (status > 0.0)
break;
if ((!svc->info.rate && iter->ok_down) ||
( svc->info.rate && iter->ok_suppressed)) {
cand[n].cand.status = !svc->info.rate ? 0.0
: copysign(svc->info.rate, -1.0);
break;
}
}
if (!svc && !dns_info_time)
svc = cand[n].svc;
}
if (svc)
break;
if (cand[n].val)
free((void*) cand[n].val);
if (n < --n_cand)
memmove(cand + n, cand + n + 1, (n_cand - n) * sizeof(*cand));
} while (n_cand);
} else
svc = 0;
if (svc) {
const char* name = (iter->ismask || iter->reverse_dns ?
(const char*) svc + svc->name : "");
if ((info = SERV_CopyInfoEx(&svc->info, name)) != 0) {
info->rate = cand[n].cand.status;
if (info->time != NCBI_TIME_INFINITE)
info->time = cand[n].svc->entry.good;
if (host_info) {
if ((host = cand[n].host) != 0) {
*host_info =
HINFO_Create(host->addr, &host->sys, sizeof(host->sys),
host->env
? (const char*) host + host->env
: 0, cand[n].arg, cand[n].val);
} else
*host_info = 0;
}
}
} else {
info = !n_cand && dns_info_time
? s_FakeDnsReturn(iter, host_info,
best_match == eHost_InitMatch ? 0/*down*/ :
best_match != eHost_BadMatch ? -1/*busy*/ : 1,
dns_info_time)
: 0;
}
for (n = 0; n < n_cand; n++) {
if (cand[n].val)
free((void*) cand[n].val);
}
if (cand)
free(cand);
if (!s_FastHeapAccess) {
#ifdef LBSM_DEBUG
CORE_LOGF(eLOG_Trace,
("LBSM heap[%p, %p, %d] for \"%s\" released",
heap, HEAP_Base(heap), HEAP_Serial(heap), iter->name));
#endif /*LBSM_DEBUG*/
CORE_LOCK_WRITE;
HEAP_Detach(heap);
CORE_UNLOCK;
heap = 0;
}
#ifdef LBSM_DEBUG
else {
CORE_LOGF(eLOG_Trace,
("LBSM heap[%p, %p, %d] for \"%s\" retained",
heap, HEAP_Base(heap), HEAP_Serial(heap), iter->name));
}
#endif /*LBSM_DEBUG*/
iter->data = heap;
return info;
}
