From 449fabba51db156af4ca11929b91b80b5a201e85 Mon Sep 17 00:00:00 2001
From: yrutschle <git1@rutschle.net>
Date: Sun, 24 Apr 2022 18:35:09 +0200
Subject: [PATCH] linked list sorted by timeout times

---
 common.h       |  9 +++++++
 sslh-conf.c    |  2 +-
 sslh-conf.h    |  3 ++-
 sslh-main.c    |  3 +++
 sslhconf.cfg   |  3 ++-
 udp-listener.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++-
 6 files changed, 82 insertions(+), 4 deletions(-)

diff --git a/common.h b/common.h
index 9732692..6f6e76c 100644
--- a/common.h
+++ b/common.h
@@ -92,6 +92,12 @@ struct queue {
     int deferred_data_size;
 };
 
+/* Double linked list for timeout management */
+typedef struct {
+    struct connection* head;
+    struct connection* tail;
+} dl_list;
+
 struct connection {
     int type;           /* SOCK_DGRAM | SOCK_STREAM */
     struct sslhcfg_protocols_item* proto; /* Where to connect to */
@@ -113,6 +119,9 @@ struct connection {
 
     time_t last_active;
 
+    /* double linked list of timeouts */
+    struct connection *timeout_prev, *timeout_next;
+
     /* We need one local socket for each target server, so we know where to
      * forward server responses */
     int target_sock;  
diff --git a/sslh-conf.c b/sslh-conf.c
index c196f5a..936ff01 100644
--- a/sslh-conf.c
+++ b/sslh-conf.c
@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Apr 10 08:52:30 2022. 
+ * on Mon Apr 18 21:21:32 2022. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
diff --git a/sslh-conf.h b/sslh-conf.h
index 6a51b38..bf6e68d 100644
--- a/sslh-conf.h
+++ b/sslh-conf.h
@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Apr 10 08:52:30 2022. 
+ * on Mon Apr 18 21:21:32 2022. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2021  Yves Rutschle
@@ -72,6 +72,7 @@ struct sslhcfg_protocols_item {
 	T_PROBE*	probe;
 	struct addrinfo*	saddr;
 	void*	data;
+	dl_list	timeouts;
 };
 
 struct sslhcfg_item {
diff --git a/sslh-main.c b/sslh-main.c
index 48d1824..8da044b 100644
--- a/sslh-main.c
+++ b/sslh-main.c
@@ -160,6 +160,9 @@ static void config_protocols()
                                   (const char**) cfg.protocols[i].alpn_protocols,
                                   cfg.protocols[i].alpn_protocols_len);
         }
+
+        p->timeouts.head = NULL;
+        p->timeouts.tail = NULL;
     }
 }
 
diff --git a/sslhconf.cfg b/sslhconf.cfg
index 9667e29..dde2844 100644
--- a/sslhconf.cfg
+++ b/sslhconf.cfg
@@ -133,7 +133,8 @@ config: {
                     # Runtime data
                     { name: "probe"; type: "runtime"; c_type: "T_PROBE*" },
                     { name: "saddr"; type: "runtime"; c_type: "struct addrinfo*" },
-                    { name: "data"; type: "runtime"; c_type: "void*" }
+                    { name: "data"; type: "runtime"; c_type: "void*" },
+                    { name: "timeouts"; type: "runtime"; c_type: "dl_list" }
                 )
             }
         )
diff --git a/udp-listener.c b/udp-listener.c
index 06966be..3efcdcb 100644
--- a/udp-listener.c
+++ b/udp-listener.c
@@ -117,6 +117,61 @@ static int new_source(hash* h, struct connection* new)
 }
 
 
+/* Double linked list utilities: push element at tail of list */
+static void list_push(dl_list* list, struct connection* cnx)
+{
+    cnx->timeout_next = NULL;
+
+    if (!list->head) {
+        cnx->timeout_prev = NULL;
+        list->head = cnx;
+    }
+
+    if (list->tail) {
+        list->tail->timeout_next = cnx;
+        cnx->timeout_prev = list->tail;
+    }
+
+    list->tail = cnx;
+}
+
+/* Double linked list utilities: remove element */
+static void list_remove(dl_list* list, struct connection* cnx)
+{
+    if (list->head == cnx) list->head = cnx->timeout_next;
+    if (list->tail == cnx) list->tail = cnx->timeout_prev;
+
+    if (cnx->timeout_prev)
+        cnx->timeout_prev->timeout_next = cnx->timeout_next;
+
+    if (cnx->timeout_next)
+        cnx->timeout_next->timeout_prev = cnx->timeout_prev;
+}
+
+static void list_dump(void) {
+    int now = time(NULL);
+    static int cnt = 0;
+
+    if (cnt++ < 1000) {
+        return;
+    }
+    cnt = 0;
+
+    FILE * f = fopen("/tmp/list.tmp", "w");
+    fprintf(f, "time: %d\n", time(NULL));
+    for (int i = 0; i < cfg.protocols_len; i++) {
+        struct connection* c = cfg.protocols[i].timeouts.head;
+        fprintf(f, "p %d %s list %p %p\n", i, cfg.protocols[i].name, cfg.protocols[i].timeouts.head, cfg.protocols[i].timeouts.tail);
+        while (c) {
+            fprintf(f, "%p %d(%d) %p %p\n", c, c->last_active, now - c->last_active, c->timeout_prev, c->timeout_next);
+            c = c->timeout_next;
+        }
+        fprintf(f, "/list\n");
+    }
+   fclose(f);
+   rename("/tmp/list.tmp", "/tmp/list");
+}
+
 
 /* Check all connections to see if a UDP connections has timed out, then free
  * it. At the same time, keep track of the closest, next timeout. Only do the
@@ -152,8 +207,9 @@ void udp_timeouts(struct loop_info* fd_info)
                 close(cnx->target_sock);
                 watchers_del_read(fd_info->watchers, i);
                 watchers_del_write(fd_info->watchers, i);
-                collection_remove_cnx(fd_info->collection, cnx);
                 hash_remove(fd_info->hash_sources, cnx);
+                list_remove(&cnx->proto->timeouts, cnx);
+                collection_remove_cnx(fd_info->collection, cnx);
             } else {
                 if (timeout < next_timeout) next_timeout = timeout;
             }
@@ -164,10 +220,18 @@ void udp_timeouts(struct loop_info* fd_info)
         fd_info->next_timeout = next_timeout;
 }
 
+
 /* Mark the connection was active */
 static void mark_active(struct connection* cnx)
 {
     cnx->last_active = time(NULL);
+
+    dl_list* list = &cnx->proto->timeouts;
+
+    list_remove(list, cnx);
+    list_push(list, cnx);
+
+    list_dump();
 }