From b94a5591286b999ae863639aaac4c8703d2d808c Mon Sep 17 00:00:00 2001
From: Michael Ortmann <41313082+michaelortmann@users.noreply.github.com>
Date: Sat, 29 Jun 2024 13:28:04 +0200
Subject: [PATCH] Fix locking proper, thank you thommey and valgrind

---
 src/dns.c |  4 ++--
 src/net.c | 17 +++++++----------
 2 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/src/dns.c b/src/dns.c
index 32bc53849..7d6658954 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -504,6 +504,7 @@ void *thread_dns_hostbyip(void *arg)
 
   i = getnameinfo((const struct sockaddr *) &addr->addr.sa, addr->addrlen,
                   dtn->host, sizeof dtn->host, NULL, 0, 0);
+  pthread_mutex_lock(&dtn->mutex);
   if (!i)
     *dtn->strerror = 0;
   else {
@@ -515,7 +516,6 @@ void *thread_dns_hostbyip(void *arg)
 #endif
       inet_ntop(AF_INET, &addr->addr.s4.sin_addr.s_addr, dtn->host, sizeof dtn->host);
   }
-  pthread_mutex_lock(&dtn->mutex);
   close(dtn->fildes[1]);
   pthread_mutex_unlock(&dtn->mutex);
   return NULL;
@@ -530,6 +530,7 @@ void *thread_dns_ipbyhost(void *arg)
 
   error = getaddrinfo(dtn->host, NULL, NULL, &res0);
   memset(addr, 0, sizeof *addr);
+  pthread_mutex_lock(&dtn->mutex);
   if (!error) {
     *dtn->strerror = 0;
 #ifdef IPV6
@@ -570,7 +571,6 @@ void *thread_dns_ipbyhost(void *arg)
     snprintf(dtn->strerror, sizeof dtn->strerror, "dns: thread_dns_ipbyhost(): getaddrinfo(): %s: %s", gai_strerror(error), ebuf);
   } else
     snprintf(dtn->strerror, sizeof dtn->strerror, "dns: thread_dns_ipbyhost(): getaddrinfo(): %s", gai_strerror(error));
-  pthread_mutex_lock(&dtn->mutex);
   close(dtn->fildes[1]);
   pthread_mutex_unlock(&dtn->mutex);
   return NULL;
diff --git a/src/net.c b/src/net.c
index 3e23acb97..ce310d73c 100644
--- a/src/net.c
+++ b/src/net.c
@@ -1053,27 +1053,24 @@ int sockread(char *s, int *len, sock_list *slist, int slistmax, int tclonly)
 #ifdef EGG_TDNS
   dtn_prev = dns_thread_head;
   for (dtn = dtn_prev->next; dtn; dtn = dtn->next) {
+    pthread_mutex_lock(&dtn->mutex);
     if (*dtn->strerror)
       debug2("%s: hostname %s", dtn->strerror, dtn->host);
     fd = dtn->fildes[0];
     if (FD_ISSET(fd, &fdr)) {
-      if (dtn->type == DTN_TYPE_HOSTBYIP) {
-        pthread_mutex_lock(&dtn->mutex);
+      if (dtn->type == DTN_TYPE_HOSTBYIP)
         call_hostbyip(&dtn->addr, dtn->host, !*dtn->strerror);
-        pthread_mutex_unlock(&dtn->mutex);
-      }
-      else {
-        pthread_mutex_lock(&dtn->mutex);
+      else
         call_ipbyhost(dtn->host, &dtn->addr, !*dtn->strerror);
-        pthread_mutex_unlock(&dtn->mutex);
-      }
-      close(dtn->fildes[0]);
+      pthread_mutex_unlock(&dtn->mutex);
+      close(fd);
       if (pthread_join(dtn->thread_id, &res))
         putlog(LOG_MISC, "*", "sockread(): pthread_join(): error = %s", strerror(errno));
       dtn_prev->next = dtn->next;
       nfree(dtn);
       dtn = dtn_prev;
-    }
+    } else
+      pthread_mutex_unlock(&dtn->mutex);
     dtn_prev = dtn;
   }
 #endif