[Server] Recursive alt search with match evidence

getUserAlts() now walks a breadth-first graph to the requested depth (clamped 1-3): each level expands frontier accounts over registration email, current client id, recent session IPs (6-month window), and historic session client ids, so identifier changes no longer hide older alts. Every row carries match_reason (email / clientid:<id> / ip:<addr>), depth, and shared_count fan-out so moderators can distinguish real alts from VPN/shared-network overlap. Command_GetUserAlts depth is plumbed through; unset depth defaults to 1, preserving previous single-hop behavior for old clients.
This commit is contained in:
Lukas Brübach 2026-10-13 20:08:25 +02:00
parent 5e1aab2492
commit 6b1bcc2caf
3 changed files with 343 additions and 52 deletions

View file

@ -34,6 +34,7 @@
#include <QVariant>
#include <QVariantList>
#include <QtGlobal>
#include <algorithm>
#include <google/protobuf/stubs/common.h>
#include <libcockatrice/deck_list/deck_list.h>
#include <libcockatrice/protocol/pb/game_replay.pb.h>
@ -1977,7 +1978,58 @@ QList<ServerInfo_UserSession> Servatrice_DatabaseInterface::getUserSessions(cons
return results;
}
QList<ServerInfo_UserAlt> Servatrice_DatabaseInterface::getUserAlts(const QString &userName)
namespace
{
constexpr int MAX_USER_ALT_DEPTH = 3;
constexpr int MAX_USER_ALTS_PER_LEVEL = 200;
// Bounds per-level work and the prepared-statement cache (keyed by query text,
// so every distinct IN-list size is a new entry on the long-lived server).
// Identifier-heavy frontiers, e.g. VPN users with hundreds of recent IPs, are
// truncated: this tool is deliberately a first-pass sweep, not an audit.
constexpr int MAX_USER_ALT_IDENTIFIERS = 200;
QString altInClause(const QString &prefix, const QList<QString> &values)
{
QStringList placeholders;
placeholders.reserve(values.size());
for (int i = 0; i < values.size(); ++i) {
placeholders << prefix + QString::number(i);
}
return QStringLiteral("(") + placeholders.join(QStringLiteral(",")) + QStringLiteral(")");
}
void altBindValues(QSqlQuery *query, const QString &prefix, const QList<QString> &values)
{
for (int i = 0; i < values.size(); ++i) {
query->bindValue(prefix + QString::number(i), values.at(i));
}
}
struct AltCandidate
{
QString name;
QString email;
QString clientId;
qint64 registrationTime = 0;
qint64 lastLogin = 0;
bool hasLastLogin = false;
int warnCount = 0;
int banCount = 0;
bool isActive = false;
};
QList<QString> cappedIdentifiers(QSet<QString> values)
{
QList<QString> list = values.values();
std::sort(list.begin(), list.end());
if (list.size() > MAX_USER_ALT_IDENTIFIERS) {
list.erase(list.begin() + MAX_USER_ALT_IDENTIFIERS, list.end());
}
return list;
}
} // namespace
QList<ServerInfo_UserAlt> Servatrice_DatabaseInterface::getUserAlts(const QString &userName, int depth)
{
QList<ServerInfo_UserAlt> results;
@ -1985,63 +2037,301 @@ QList<ServerInfo_UserAlt> Servatrice_DatabaseInterface::getUserAlts(const QStrin
return results;
}
// Seed account identifiers used to find related accounts
QSqlQuery *seedQuery = prepareQuery("SELECT email, clientid FROM {prefix}_users WHERE name = :user_name");
seedQuery->bindValue(":user_name", userName);
if (!execSqlQuery(seedQuery) || !seedQuery->next()) {
return results;
if (depth < 1) {
depth = 1;
} else if (depth > MAX_USER_ALT_DEPTH) {
depth = MAX_USER_ALT_DEPTH;
}
const QString seedEmail = seedQuery->value(0).toString();
const QString seedClientId = seedQuery->value(1).toString();
QString queryString = "SELECT u.name, u.email, u.clientid, UNIX_TIMESTAMP(u.registrationDate), "
// Seed must exist; its row anchors the result at depth 0.
QSqlQuery *seedQuery = prepareQuery("SELECT u.name, u.email, u.clientid, UNIX_TIMESTAMP(u.registrationDate), "
"UNIX_TIMESTAMP(a.last_login), "
"(SELECT COUNT(*) FROM {prefix}_warnings w WHERE w.user_id = u.id), "
"(SELECT COUNT(*) FROM {prefix}_bans b WHERE b.user_name = u.name), "
"u.active "
"FROM {prefix}_users u "
"LEFT JOIN {prefix}_user_analytics a ON a.id = u.id "
"WHERE u.name = :user_name";
if (!seedEmail.isEmpty()) {
queryString.append(" OR u.email = :seed_email");
}
if (!seedClientId.isEmpty()) {
queryString.append(" OR u.clientid = :seed_clientid");
}
queryString.append(" OR u.name IN (SELECT DISTINCT s.user_name FROM {prefix}_sessions s "
"WHERE s.ip_address IN (SELECT DISTINCT s2.ip_address FROM {prefix}_sessions s2 "
"WHERE s2.user_name = :user_name"
" AND s2.start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH))"
" AND s.start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH)) "
"ORDER BY u.name LIMIT 200");
QSqlQuery *query = prepareQuery(queryString);
query->bindValue(":user_name", userName);
if (!seedEmail.isEmpty()) {
query->bindValue(":seed_email", seedEmail);
}
if (!seedClientId.isEmpty()) {
query->bindValue(":seed_clientid", seedClientId);
"WHERE u.name = :user_name");
seedQuery->bindValue(":user_name", userName);
if (!execSqlQuery(seedQuery) || !seedQuery->next()) {
return results;
}
if (!execSqlQuery(query)) {
auto appendAlt = [&results](const AltCandidate &candidate, const QString &matchReason, int matchDepth,
int sharedCount) {
ServerInfo_UserAlt altDetails;
altDetails.set_user_name(candidate.name.toStdString());
altDetails.set_email(candidate.email.toStdString());
altDetails.set_clientid(candidate.clientId.toStdString());
altDetails.set_registration_time(candidate.registrationTime);
if (candidate.hasLastLogin) {
altDetails.set_last_login(candidate.lastLogin);
}
altDetails.set_warn_count(candidate.warnCount);
altDetails.set_ban_count(candidate.banCount);
altDetails.set_is_active(candidate.isActive);
altDetails.set_match_reason(matchReason.toStdString());
altDetails.set_depth(static_cast<google::protobuf::uint32>(matchDepth));
altDetails.set_shared_count(static_cast<google::protobuf::uint32>(sharedCount));
results << altDetails;
};
AltCandidate seed{.name = seedQuery->value(0).toString(),
.email = seedQuery->value(1).toString(),
.clientId = seedQuery->value(2).toString(),
.registrationTime = seedQuery->value(3).toLongLong(),
.lastLogin = seedQuery->value(4).toLongLong(),
.hasLastLogin = !seedQuery->value(4).isNull(),
.warnCount = seedQuery->value(5).toInt(),
.banCount = seedQuery->value(6).toInt(),
.isActive = seedQuery->value(7).toBool()};
appendAlt(seed, QStringLiteral("self"), 0, 1);
QSet<QString> visited{userName};
QList<QString> frontier{userName};
for (int level = 1; level <= depth && !frontier.isEmpty(); ++level) {
const QString frontierClause = altInClause(QStringLiteral(":alt_name"), frontier);
// Current identifiers of the frontier: registration email + client id.
QSet<QString> emails;
QSet<QString> clientIds;
QSet<QString> ips;
QSqlQuery *frontierQuery =
prepareQuery(QStringLiteral("SELECT email, clientid FROM {prefix}_users WHERE name IN ") + frontierClause);
altBindValues(frontierQuery, QStringLiteral(":alt_name"), frontier);
if (execSqlQuery(frontierQuery)) {
while (frontierQuery->next()) {
const QString email = frontierQuery->value(0).toString();
const QString clientId = frontierQuery->value(1).toString();
if (!email.isEmpty()) {
emails << email;
}
if (!clientId.isEmpty()) {
clientIds << clientId;
}
}
}
// Recent session identifiers: IPs plus historic client ids.
QSqlQuery *sessionQuery = prepareQuery(
QStringLiteral("SELECT DISTINCT ip_address, clientid FROM {prefix}_sessions WHERE user_name IN ") +
frontierClause + QStringLiteral(" AND start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH)"));
altBindValues(sessionQuery, QStringLiteral(":alt_name"), frontier);
if (execSqlQuery(sessionQuery)) {
while (sessionQuery->next()) {
const QString ip = sessionQuery->value(0).toString();
const QString clientId = sessionQuery->value(1).toString();
if (!ip.isEmpty()) {
ips << ip;
}
if (!clientId.isEmpty()) {
clientIds << clientId;
}
}
}
if (emails.isEmpty() && clientIds.isEmpty() && ips.isEmpty()) {
break;
}
// Accounts sharing any frontier identifier. Historic client ids are matched
// through past sessions so identifier changes do not hide older alts.
QString candidateString =
QStringLiteral("SELECT u.name, u.email, u.clientid, UNIX_TIMESTAMP(u.registrationDate), "
"UNIX_TIMESTAMP(a.last_login), "
"(SELECT COUNT(*) FROM {prefix}_warnings w WHERE w.user_id = u.id), "
"(SELECT COUNT(*) FROM {prefix}_bans b WHERE b.user_name = u.name), "
"u.active "
"FROM {prefix}_users u "
"LEFT JOIN {prefix}_user_analytics a ON a.id = u.id "
"WHERE ");
QStringList conditions;
QList<QString> emailList = cappedIdentifiers(emails);
QList<QString> clientIdList = cappedIdentifiers(clientIds);
QList<QString> ipList = cappedIdentifiers(ips);
if (!emailList.isEmpty()) {
conditions << QStringLiteral("u.email IN ") + altInClause(QStringLiteral(":alt_email"), emailList);
}
if (!clientIdList.isEmpty()) {
conditions << QStringLiteral("u.clientid IN ") + altInClause(QStringLiteral(":alt_cid"), clientIdList);
}
if (!ipList.isEmpty()) {
conditions << QStringLiteral("u.name IN (SELECT DISTINCT s.user_name FROM {prefix}_sessions s WHERE "
"s.ip_address IN ") +
altInClause(QStringLiteral(":alt_ip"), ipList) +
QStringLiteral(" AND s.start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH))");
}
if (!clientIdList.isEmpty()) {
conditions << QStringLiteral("u.name IN (SELECT DISTINCT s.user_name FROM {prefix}_sessions s WHERE "
"s.clientid IN ") +
altInClause(QStringLiteral(":alt_hcid"), clientIdList) +
QStringLiteral(" AND s.start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH))");
}
candidateString += conditions.join(QStringLiteral(" OR "));
candidateString += QStringLiteral(" ORDER BY u.name LIMIT ") + QString::number(MAX_USER_ALTS_PER_LEVEL);
QSqlQuery *candidateQuery = prepareQuery(candidateString);
altBindValues(candidateQuery, QStringLiteral(":alt_email"), emailList);
altBindValues(candidateQuery, QStringLiteral(":alt_cid"), clientIdList);
altBindValues(candidateQuery, QStringLiteral(":alt_ip"), ipList);
altBindValues(candidateQuery, QStringLiteral(":alt_hcid"), clientIdList);
if (!execSqlQuery(candidateQuery)) {
qCWarning(DatabaseInterfaceLog) << "Failed to collect user alt information: SQL Error";
return results;
}
while (query->next()) {
ServerInfo_UserAlt altDetails;
altDetails.set_user_name(query->value(0).toString().toStdString());
altDetails.set_email(query->value(1).toString().toStdString());
altDetails.set_clientid(query->value(2).toString().toStdString());
altDetails.set_registration_time(query->value(3).toLongLong());
if (!query->value(4).isNull()) {
altDetails.set_last_login(query->value(4).toLongLong());
QList<AltCandidate> candidates;
while (candidateQuery->next()) {
AltCandidate candidate;
candidate.name = candidateQuery->value(0).toString();
if (visited.contains(candidate.name)) {
continue;
}
altDetails.set_warn_count(query->value(5).toInt());
altDetails.set_ban_count(query->value(6).toInt());
altDetails.set_is_active(query->value(7).toBool());
results << altDetails;
candidate.email = candidateQuery->value(1).toString();
candidate.clientId = candidateQuery->value(2).toString();
candidate.registrationTime = candidateQuery->value(3).toLongLong();
candidate.hasLastLogin = !candidateQuery->value(4).isNull();
candidate.lastLogin = candidateQuery->value(4).toLongLong();
candidate.warnCount = candidateQuery->value(5).toInt();
candidate.banCount = candidateQuery->value(6).toInt();
candidate.isActive = candidateQuery->value(7).toBool();
candidates << candidate;
}
// Resolve session-level evidence (shared IP or historic client id) for
// candidates that do not match on current email or client id.
QMap<QString, QString> candidateIp;
QMap<QString, QString> candidateHistoricClientId;
QList<QString> unexplained;
for (const AltCandidate &candidate : candidates) {
const bool emailMatch = !candidate.email.isEmpty() && emails.contains(candidate.email);
const bool clientIdMatch = !candidate.clientId.isEmpty() && clientIds.contains(candidate.clientId);
if (!emailMatch && !clientIdMatch) {
unexplained << candidate.name;
}
}
if (!unexplained.isEmpty() && (!ips.isEmpty() || !clientIds.isEmpty())) {
QString evidenceString =
QStringLiteral("SELECT DISTINCT user_name, ip_address, clientid FROM {prefix}_sessions WHERE "
"user_name IN ") +
altInClause(QStringLiteral(":alt_ev"), unexplained) + QStringLiteral(" AND (");
QStringList evidenceConditions;
if (!ipList.isEmpty()) {
evidenceConditions << QStringLiteral("ip_address IN ") +
altInClause(QStringLiteral(":alt_eip"), ipList);
}
if (!clientIdList.isEmpty()) {
evidenceConditions << QStringLiteral("clientid IN ") +
altInClause(QStringLiteral(":alt_ecid"), clientIdList);
}
evidenceString += evidenceConditions.join(QStringLiteral(" OR "));
evidenceString += QStringLiteral(") AND start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH)");
QSqlQuery *evidenceQuery = prepareQuery(evidenceString);
altBindValues(evidenceQuery, QStringLiteral(":alt_ev"), unexplained);
altBindValues(evidenceQuery, QStringLiteral(":alt_eip"), ipList);
altBindValues(evidenceQuery, QStringLiteral(":alt_ecid"), clientIdList);
if (execSqlQuery(evidenceQuery)) {
while (evidenceQuery->next()) {
const QString name = evidenceQuery->value(0).toString();
const QString ip = evidenceQuery->value(1).toString();
const QString clientId = evidenceQuery->value(2).toString();
if (!ip.isEmpty() && ips.contains(ip) && !candidateIp.contains(name)) {
candidateIp.insert(name, ip);
}
if (!clientId.isEmpty() && clientIds.contains(clientId) &&
!candidateHistoricClientId.contains(name)) {
candidateHistoricClientId.insert(name, clientId);
}
}
}
}
// Fan-out counts so moderators can spot VPN/shared-network false positives.
QMap<QString, int> emailCounts;
QMap<QString, int> clientIdCounts;
QMap<QString, int> ipCounts;
QSet<QString> neededEmails;
QSet<QString> neededClientIds;
QSet<QString> neededIps;
for (const AltCandidate &candidate : candidates) {
if (!candidate.email.isEmpty() && emails.contains(candidate.email)) {
neededEmails << candidate.email;
} else if (!candidate.clientId.isEmpty() && clientIds.contains(candidate.clientId)) {
neededClientIds << candidate.clientId;
} else if (candidateHistoricClientId.contains(candidate.name)) {
neededClientIds << candidateHistoricClientId.value(candidate.name);
} else if (candidateIp.contains(candidate.name)) {
neededIps << candidateIp.value(candidate.name);
}
}
if (!neededEmails.isEmpty()) {
const QList<QString> neededEmailList = neededEmails.values();
QSqlQuery *countQuery = prepareQuery(QStringLiteral("SELECT email, COUNT(*) FROM {prefix}_users WHERE "
"email IN ") +
altInClause(QStringLiteral(":alt_ce"), neededEmailList) +
QStringLiteral(" GROUP BY email"));
altBindValues(countQuery, QStringLiteral(":alt_ce"), neededEmailList);
if (execSqlQuery(countQuery)) {
while (countQuery->next()) {
emailCounts.insert(countQuery->value(0).toString(), countQuery->value(1).toInt());
}
}
}
if (!neededClientIds.isEmpty()) {
const QList<QString> neededClientIdList = neededClientIds.values();
QSqlQuery *countQuery = prepareQuery(QStringLiteral("SELECT clientid, COUNT(*) FROM {prefix}_users WHERE "
"clientid IN ") +
altInClause(QStringLiteral(":alt_cc"), neededClientIdList) +
QStringLiteral(" GROUP BY clientid"));
altBindValues(countQuery, QStringLiteral(":alt_cc"), neededClientIdList);
if (execSqlQuery(countQuery)) {
while (countQuery->next()) {
clientIdCounts.insert(countQuery->value(0).toString(), countQuery->value(1).toInt());
}
}
}
if (!neededIps.isEmpty()) {
const QList<QString> neededIpList = neededIps.values();
QSqlQuery *countQuery = prepareQuery(
QStringLiteral("SELECT ip_address, COUNT(DISTINCT user_name) FROM {prefix}_sessions WHERE "
"ip_address IN ") +
altInClause(QStringLiteral(":alt_ci"), neededIpList) +
QStringLiteral(" AND start_time >= DATE_SUB(NOW(), INTERVAL 6 MONTH) GROUP BY ip_address"));
altBindValues(countQuery, QStringLiteral(":alt_ci"), neededIpList);
if (execSqlQuery(countQuery)) {
while (countQuery->next()) {
ipCounts.insert(countQuery->value(0).toString(), countQuery->value(1).toInt());
}
}
}
QList<QString> nextFrontier;
for (const AltCandidate &candidate : candidates) {
QString matchReason;
int sharedCount = 1;
if (!candidate.email.isEmpty() && emails.contains(candidate.email)) {
matchReason = QStringLiteral("email");
sharedCount = qMax(1, emailCounts.value(candidate.email, 1));
} else if (!candidate.clientId.isEmpty() && clientIds.contains(candidate.clientId)) {
matchReason = QStringLiteral("clientid:") + candidate.clientId;
sharedCount = qMax(1, clientIdCounts.value(candidate.clientId, 1));
} else if (candidateHistoricClientId.contains(candidate.name)) {
const QString historicId = candidateHistoricClientId.value(candidate.name);
matchReason = QStringLiteral("clientid:") + historicId;
sharedCount = qMax(1, clientIdCounts.value(historicId, 1));
} else if (candidateIp.contains(candidate.name)) {
const QString ip = candidateIp.value(candidate.name);
matchReason = QStringLiteral("ip:") + ip;
sharedCount = qMax(1, ipCounts.value(ip, 1));
} else {
continue;
}
appendAlt(candidate, matchReason, level, sharedCount);
visited.insert(candidate.name);
nextFrontier << candidate.name;
}
frontier = nextFrontier;
}
return results;

View file

@ -224,7 +224,7 @@ public:
const QString &beforeTime = QString(),
bool *hasMore = nullptr);
QList<ServerInfo_UserSession> getUserSessions(const QString &userName, int limit);
QList<ServerInfo_UserAlt> getUserAlts(const QString &userName);
QList<ServerInfo_UserAlt> getUserAlts(const QString &userName, int depth = 1);
QList<ServerInfo_ModeratorLogin> getModeratorLastLogins();
// Uptime snapshot as recorded by Servatrice::statusUpdate() into the

View file

@ -2595,7 +2595,8 @@ Response::ResponseCode AbstractServerSocketInterface::cmdGetUserAlts(const Comma
}
Response_UserAlts *re = new Response_UserAlts;
const QList<ServerInfo_UserAlt> alts = sqlInterface->getUserAlts(userName);
const int depth = cmd.has_depth() ? static_cast<int>(cmd.depth()) : 1;
const QList<ServerInfo_UserAlt> alts = sqlInterface->getUserAlts(userName, depth);
for (const ServerInfo_UserAlt &alt : alts) {
re->add_alts()->CopyFrom(alt);
}