From afef79bee7eb86e7f395fc2b38f9e6cf9a4fc269 Mon Sep 17 00:00:00 2001
From: Michael Ortmann <41313082+michaelortmann@users.noreply.github.com>
Date: Sun, 18 Feb 2024 15:07:12 +0100
Subject: [PATCH] Join threads instead of detach

Found by: michaelortmann
Patch by: michaelortmann
---
 src/dns.c     | 18 ++----------------
 src/eggdrop.h |  1 +
 src/net.c     |  3 +++
 3 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/src/dns.c b/src/dns.c
index ab1fdbeae..2e5035b88 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -568,7 +568,6 @@ void *thread_dns_ipbyhost(void *arg)
 void core_dns_hostbyip(sockname_t *addr)
 {
   struct dns_thread_node *dtn = nmalloc(sizeof(struct dns_thread_node));
-  pthread_t thread; /* only used by pthread_create(), no need to save */
   pthread_attr_t attr;
 
   if (pthread_attr_init(&attr)) {
@@ -577,12 +576,6 @@ void core_dns_hostbyip(sockname_t *addr)
     nfree(dtn);
     return;
   }
-  if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)) {
-    putlog(LOG_MISC, "*", "core_dns_hostbyip(): pthread_attr_setdetachstate(): error = %s", strerror(errno));
-    call_hostbyip(addr, iptostr(&addr->addr.sa), 0);
-    nfree(dtn);
-    return;
-  }
   if (pthread_mutex_init(&dtn->mutex, NULL))
     fatal("ERROR: core_dns_hostbyip(): pthread_mutex_init() failed", 0);
   if (pipe(dtn->fildes) < 0) {
@@ -592,7 +585,7 @@ void core_dns_hostbyip(sockname_t *addr)
     return;
   }
   memcpy(&dtn->addr, addr, sizeof *addr);
-  if (pthread_create(&thread, &attr, thread_dns_hostbyip, (void *) dtn)) {
+  if (pthread_create(&(dtn->thread_id), &attr, thread_dns_hostbyip, (void *) dtn)) {
     putlog(LOG_MISC, "*", "core_dns_hostbyip(): pthread_create(): error = %s", strerror(errno));
     call_hostbyip(addr, iptostr(&addr->addr.sa), 0);
     close(dtn->fildes[0]);
@@ -609,7 +602,6 @@ void core_dns_ipbyhost(char *host)
 {
   sockname_t addr;
   struct dns_thread_node *dtn;
-  pthread_t thread; /* only used by pthread_create(), no need to save  */
   pthread_attr_t attr;
 
   /* if addr is ip instead of host */
@@ -624,12 +616,6 @@ void core_dns_ipbyhost(char *host)
     nfree(dtn);
     return;
   }
-  if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)) {
-    putlog(LOG_MISC, "*", "core_dns_ipbyhost(): pthread_attr_setdetachstate(): error = %s", strerror(errno));
-    call_ipbyhost(host, &addr, 0);
-    nfree(dtn);
-    return;
-  }
   if (pthread_mutex_init(&dtn->mutex, NULL))
     fatal("ERROR: core_dns_ipbyhost(): pthread_mutex_init() failed", 0);
   if (pipe(dtn->fildes) < 0) {
@@ -641,7 +627,7 @@ void core_dns_ipbyhost(char *host)
   dtn->next = dns_thread_head->next;
   dns_thread_head->next = dtn;
   strlcpy(dtn->host, host, sizeof dtn->host);
-  if (pthread_create(&thread, &attr, thread_dns_ipbyhost, (void *) dtn)) {
+  if (pthread_create(&(dtn->thread_id), &attr, thread_dns_ipbyhost, (void *) dtn)) {
     putlog(LOG_MISC, "*", "core_dns_ipbyhost(): pthread_create(): error = %s", strerror(errno));
     call_ipbyhost(host, &addr, 0);
     close(dtn->fildes[0]);
diff --git a/src/eggdrop.h b/src/eggdrop.h
index a7774e294..076a16252 100644
--- a/src/eggdrop.h
+++ b/src/eggdrop.h
@@ -751,6 +751,7 @@ enum {
 
 /* linked list instead of array because of multi threading */
 struct dns_thread_node {
+  pthread_t thread_id;
   pthread_mutex_t mutex;
   int fildes[2];
   int type;
diff --git a/src/net.c b/src/net.c
index 9ea150019..c8aa62cd5 100644
--- a/src/net.c
+++ b/src/net.c
@@ -899,6 +899,7 @@ int sockread(char *s, int *len, sock_list *slist, int slistmax, int tclonly)
 #ifdef EGG_TDNS
   int fd;
   struct dns_thread_node *dtn, *dtn_prev;
+  void *res;
 #endif
 
   maxfd_r = preparefdset(&fdr, slist, slistmax, tclonly, TCL_READABLE);
@@ -1065,6 +1066,8 @@ int sockread(char *s, int *len, sock_list *slist, int slistmax, int tclonly)
         pthread_mutex_unlock(&dtn->mutex);
       }
       close(dtn->fildes[0]);
+      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;