Add file missing in 26cc5f4

psiphon/server/redis.go

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2016, Psiphon Inc.
+ * All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package server
+
+import (
+	"encoding/json"
+
+	"github.com/Psiphon-Inc/redigo/redis"
+	"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon"
+)
+
+// UpdateRedisForLegacyPsiWeb sets the Psiphon session and discovery records for
+// a new SSH connection following the conventions of the legacy psi_web component.
+// This facility is used so psi_web can use the GeoIP values the SSH server has
+// resolved for the user connection.
+// The redis database indexes, expiry values, and record schemas all match the
+// legacy psi_web configuration.
+func UpdateRedisForLegacyPsiWeb(psiphonSessionID string, geoIPData GeoIPData) error {
+
+	redisSessionDBIndex := 0
+
+	//  Discard sessions older than 60 minutes
+	sessionExpireSeconds := 60 * 60
+
+	sessionRecord, err := json.Marshal(
+		struct {
+			country string `json:"region"`
+			city    string `json:"city"`
+			ISP     string `json:"isp"`
+		}{geoIPData.Country, geoIPData.City, geoIPData.ISP})
+	if err != nil {
+		return psiphon.ContextError(err)
+	}
+
+	redisDiscoveryDBIndex := 1
+
+	// Discard discovery records older than 5 minutes
+	discoveryExpireSeconds := 60 * 5
+
+	// TODO: implement psi_ops_discovery.calculate_ip_address_strategy_value
+	discoveryValue := 0
+
+	discoveryRecord, err := json.Marshal(
+		struct {
+			value int `json:"client_ip_address_strategy_value"`
+		}{discoveryValue})
+	if err != nil {
+		return psiphon.ContextError(err)
+	}
+
+	conn := redisPool.Get()
+
+	// Note: using SET with NX (set if not exists) so as to not clobber
+	// any existing records set by an upstream connection server (i.e.,
+	// meek server). We allow expiry deadline extension unconditionally.
+
+	conn.Send("MULTI")
+	conn.Send("SELECT", redisSessionDBIndex)
+	conn.Send("SET", psiphonSessionID, sessionRecord, "NX", "EX", sessionExpireSeconds)
+	conn.Send("SELECT", redisDiscoveryDBIndex)
+	conn.Send("SET", psiphonSessionID, discoveryRecord, "NX", "EX", discoveryExpireSeconds)
+	_, err = conn.Do("EXEC")
+	if err != nil {
+		return psiphon.ContextError(err)
+	}
+
+	return nil
+}
+
+var redisPool *redis.Pool
+
+func InitRedis(config *Config) error {
+	redisPool := &redis.Pool{
+		Dial: func() (redis.Conn, error) {
+			return redis.Dial("tcp", config.RedisServerAddress)
+		},
+		MaxIdle:     REDIS_POOL_MAX_IDLE,
+		MaxActive:   REDIS_POOL_MAX_ACTIVE,
+		Wait:        false,
+		IdleTimeout: REDIS_POOL_IDLE_TIMEOUT,
+	}
+
+	// Exercise a connection to the configured redis server so
+	// that Init fails if the configuration is incorrect or the
+	// server is not responding.
+	conn := redisPool.Get()
+	_, err := conn.Do("PING")
+	conn.Close()
+
+	return err
+}