[ipfire-2.x.git] / src / patches / dnsmasq / 0058-Fix-boilerplate-code-for-re-running-system-calls-on-.patch

From ff841ebf5a5d6864ff48571f607c32ce80dbb75a Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Wed, 11 Mar 2015 21:36:30 +0000
Subject: [PATCH 058/113] Fix boilerplate code for re-running system calls on
 EINTR and EAGAIN etc.

The nasty code with static variable in retry_send() which
avoids looping forever needs to be called on success of the syscall,
to reset the static variable.
---
 src/bpf.c     |  2 +-
 src/dhcp.c    |  2 +-
 src/dhcp6.c   |  6 +++---
 src/dnsmasq.c | 35 +++++++++++++++++----------------
 src/dnsmasq.h |  2 +-
 src/forward.c | 41 ++++++++++++++++++--------------------
 src/ipset.c   |  8 ++++----
 src/loop.c    |  5 +++--
 src/netlink.c |  8 ++++----
 src/radv.c    |  5 +++--
 src/util.c    | 63 ++++++++++++++++++++++++++++++++++-------------------------
 11 files changed, 93 insertions(+), 84 deletions(-)

diff --git a/src/bpf.c b/src/bpf.c
index 997d87421bed..a066641f969f 100644
--- a/src/bpf.c
+++ b/src/bpf.c
@@ -359,7 +359,7 @@ void send_via_bpf(struct dhcp_packet *mess, size_t len,
   iov[3].iov_base = mess;
   iov[3].iov_len = len;
 
-  while (writev(daemon->dhcp_raw_fd, iov, 4) == -1 && retry_send());
+  while (retry_send(writev(daemon->dhcp_raw_fd, iov, 4)));
 }
 
 #endif /* defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP) */
diff --git a/src/dhcp.c b/src/dhcp.c
index f29be9b489a7..5c3089ab94ff 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -443,7 +443,7 @@ void dhcp_packet(time_t now, int pxe_fd)
   setsockopt(fd, IPPROTO_IP, IP_BOUND_IF, &iface_index, sizeof(iface_index));
 #endif
   
-  while(sendmsg(fd, &msg, 0) == -1 && retry_send());
+  while(retry_send(sendmsg(fd, &msg, 0)));
 }
  
 /* check against secondary interface addresses */
diff --git a/src/dhcp6.c b/src/dhcp6.c
index c7144f5fee7c..ee2aa5d3bf3c 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -225,9 +225,9 @@ void dhcp6_packet(time_t now)
   if (port != 0)
     {
       from.sin6_port = htons(port);
-      while (sendto(daemon->dhcp6fd, daemon->outpacket.iov_base, save_counter(0), 
-		    0, (struct sockaddr *)&from, sizeof(from)) == -1 &&
-	   retry_send());
+      while (retry_send(sendto(daemon->dhcp6fd, daemon->outpacket.iov_base, 
+			       save_counter(0), 0, (struct sockaddr *)&from, 
+			       sizeof(from))));
     }
 }
 
diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index f3e5bcffec4f..b784951950d4 100644
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -444,7 +444,7 @@ int main (int argc, char **argv)
 	      char *msg;
 
 	      /* close our copy of write-end */
-	      close(err_pipe[1]);
+	      while (retry_send(close(err_pipe[1])));
 	      
 	      /* check for errors after the fork */
 	      if (read_event(err_pipe[0], &ev, &msg))
@@ -453,7 +453,7 @@ int main (int argc, char **argv)
 	      _exit(EC_GOOD);
 	    } 
 	  
-	  close(err_pipe[0]);
+	  while (retry_send(close(err_pipe[0])));
 
 	  /* NO calls to die() from here on. */
 	  
@@ -505,10 +505,12 @@ int main (int argc, char **argv)
 	    {
 	      if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0))
 		err = 1;
-	      
-	      while (!err && close(fd) == -1)
-		if (!retry_send())
-		  err = 1;
+	      else 
+		{
+		  while (retry_send(close(fd)));
+		  if (errno != 0)
+		    err = 1;
+		}
 	    }
 
 	  if (err)
@@ -813,7 +815,7 @@ int main (int argc, char **argv)
 
   /* finished start-up - release original process */
   if (err_pipe[1] != -1)
-    close(err_pipe[1]);
+    while (retry_send(close(err_pipe[1])));
   
   if (daemon->port != 0)
     check_servers();
@@ -1319,7 +1321,7 @@ static void async_event(int pipe, time_t now)
 	    do {
 	      helper_write();
 	    } while (!helper_buf_empty() || do_script_run(now));
-	    close(daemon->helperfd);
+	    while (retry_send(close(daemon->helperfd)));
 	  }
 #endif
 	
@@ -1544,7 +1546,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
 	  
 	  if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1)
 	    {
-	      close(confd);
+	      while (retry_send(close(confd)));
 	      continue;
 	    }
 	  
@@ -1609,7 +1611,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
 	  if (!client_ok)
 	    {
 	      shutdown(confd, SHUT_RDWR);
-	      close(confd);
+	      while (retry_send(close(confd)));
 	    }
 #ifndef NO_FORK
 	  else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0)
@@ -1624,7 +1626,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
 			break;
 		      }
 		}
-	      close(confd);
+	      while (retry_send(close(confd)));
 
 	      /* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */
 	      daemon->log_id += TCP_MAX_QUERIES;
@@ -1669,7 +1671,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
 	      buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns);
 	       
 	      shutdown(confd, SHUT_RDWR);
-	      close(confd);
+	      while (retry_send(close(confd)));
 	      
 	      if (buff)
 		free(buff);
@@ -1678,7 +1680,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
 		if (s->tcpfd != -1)
 		  {
 		    shutdown(s->tcpfd, SHUT_RDWR);
-		    close(s->tcpfd);
+		    while (retry_send(close(s->tcpfd)));
 		  }
 #ifndef NO_FORK		   
 	      if (!option_bool(OPT_DEBUG))
@@ -1756,9 +1758,8 @@ int icmp_ping(struct in_addr addr)
     j = (j & 0xffff) + (j >> 16);  
   packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j;
   
-  while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, 
-		(struct sockaddr *)&saddr, sizeof(saddr)) == -1 &&
-	 retry_send());
+  while (retry_send(sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, 
+			   (struct sockaddr *)&saddr, sizeof(saddr))));
   
   for (now = start = dnsmasq_time(); 
        difftime(now, start) < (float)PING_WAIT;)
@@ -1820,7 +1821,7 @@ int icmp_ping(struct in_addr addr)
     }
   
 #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK)
-  close(fd);
+  while (retry_send(close(fd)));
 #else
   opt = 1;
   setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index fc7259881358..de95d0e875e3 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -1177,7 +1177,7 @@ int is_same_net6(struct in6_addr *a, struct in6_addr *b, int prefixlen);
 u64 addr6part(struct in6_addr *addr);
 void setaddr6part(struct in6_addr *addr, u64 host);
 #endif
-int retry_send(void);
+int retry_send(ssize_t rc);
 void prettyprint_time(char *buf, unsigned int t);
 int prettyprint_addr(union mysockaddr *addr, char *buf);
 int parse_hex(char *in, unsigned char *out, int maxlen, 
diff --git a/src/forward.c b/src/forward.c
index 438e9fa490b8..7c0fa8da3fdf 100644
--- a/src/forward.c
+++ b/src/forward.c
@@ -103,15 +103,11 @@ int send_from(int fd, int nowild, char *packet, size_t len,
 #endif
     }
   
-  while (sendmsg(fd, &msg, 0) == -1)
+  while (retry_send(sendmsg(fd, &msg, 0)));
+
+  /* If interface is still in DAD, EINVAL results - ignore that. */
+  if (errno != 0 && errno != EINVAL)
     {
-      if (retry_send())
-	continue;
-      
-      /* If interface is still in DAD, EINVAL results - ignore that. */
-      if (errno == EINVAL)
-	break;
-      
       my_syslog(LOG_ERR, _("failed to send packet: %s"), strerror(errno));
       return 0;
     }
@@ -297,9 +293,9 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 		fd = forward->rfd4->fd;
 	    }
 	  
-	  while (sendto(fd, (char *)header, plen, 0,
-			&forward->sentto->addr.sa,
-			sa_len(&forward->sentto->addr)) == -1 && retry_send());
+	  while (retry_send( sendto(fd, (char *)header, plen, 0,
+				    &forward->sentto->addr.sa,
+				    sa_len(&forward->sentto->addr))));
 	  
 	  return 1;
 	}
@@ -469,14 +465,12 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 #endif
 		}
 	      
-	      if (sendto(fd, (char *)header, plen, 0,
-			 &start->addr.sa,
-			 sa_len(&start->addr)) == -1)
-		{
-		  if (retry_send())
-		    continue;
-		}
-	      else
+	      if (retry_send(sendto(fd, (char *)header, plen, 0,
+				    &start->addr.sa,
+				    sa_len(&start->addr))))
+		continue;
+	    
+	      if (errno == 0)
 		{
 		  /* Keep info in case we want to re-send this packet */
 		  daemon->srv_save = start;
@@ -932,7 +926,9 @@ void reply_query(int fd, int family, time_t now)
 		  
 		  if (fd != -1)
 		    {
-		      while (sendto(fd, (char *)header, nn, 0, &server->addr.sa, sa_len(&server->addr)) == -1 && retry_send()); 
+		      while (retry_send(sendto(fd, (char *)header, nn, 0, 
+					       &server->addr.sa, 
+					       sa_len(&server->addr)))); 
 		      server->queries++;
 		    }
 		  
@@ -2228,8 +2224,9 @@ void resend_query()
       else
 	return;
       
-      while(sendto(fd, daemon->packet, daemon->packet_len, 0,
-		   &daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send()); 
+      while(retry_send(sendto(fd, daemon->packet, daemon->packet_len, 0,
+			      &daemon->srv_save->addr.sa, 
+			      sa_len(&daemon->srv_save->addr)))); 
     }
 }
 
diff --git a/src/ipset.c b/src/ipset.c
index 8c5b72722371..a315e86bc7f4 100644
--- a/src/ipset.c
+++ b/src/ipset.c
@@ -121,7 +121,6 @@ static int new_add_to_ipset(const char *setname, const struct all_addr *ipaddr,
   struct my_nlattr *nested[2];
   uint8_t proto;
   int addrsz = INADDRSZ;
-  ssize_t rc;
 
 #ifdef HAVE_IPV6
   if (af == AF_INET6)
@@ -162,9 +161,10 @@ static int new_add_to_ipset(const char *setname, const struct all_addr *ipaddr,
   nested[1]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[1];
   nested[0]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[0];
 	
-  while ((rc = sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
-		      (struct sockaddr *)&snl, sizeof(snl))) == -1 && retry_send());
-  return rc;
+  while (retry_send(sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
+			   (struct sockaddr *)&snl, sizeof(snl))));
+								    
+  return errno == 0 ? 0 : -1;
 }
 
 
diff --git a/src/loop.c b/src/loop.c
index 565f7d8e58e0..c9ed075670de 100644
--- a/src/loop.c
+++ b/src/loop.c
@@ -45,8 +45,9 @@ void loop_send_probes()
 	     fd = rfd->fd;
 	   }
 
-	 while (sendto(fd, daemon->packet, len, 0, &serv->addr.sa, sa_len(&serv->addr)) == -1 && retry_send());
-
+	 while (retry_send(sendto(fd, daemon->packet, len, 0, 
+				  &serv->addr.sa, sa_len(&serv->addr))));
+	 
 	 free_rfd(rfd);
        }
 }
diff --git a/src/netlink.c b/src/netlink.c
index 10f94db25a14..753784dc20b4 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -169,10 +169,10 @@ int iface_enumerate(int family, void *parm, int (*callback)())
   req.g.rtgen_family = family; 
 
   /* Don't block in recvfrom if send fails */
-  while((len = sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, 
-		      (struct sockaddr *)&addr, sizeof(addr))) == -1 && retry_send());
-  
-  if (len == -1)
+  while(retry_send(sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, 
+			  (struct sockaddr *)&addr, sizeof(addr))));
+
+  if (errno != 0)
     return 0;
     
   while (1)
diff --git a/src/radv.c b/src/radv.c
index 6da125b864ae..d0faddf8684a 100644
--- a/src/radv.c
+++ b/src/radv.c
@@ -479,8 +479,9 @@ static void send_ra(time_t now, int iface, char *iface_name, struct in6_addr *de
       setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &iface, sizeof(iface));
     }
   
-  while (sendto(daemon->icmp6fd, daemon->outpacket.iov_base, save_counter(0), 0, 
-		(struct sockaddr *)&addr, sizeof(addr)) == -1 && retry_send());
+  while (retry_send(sendto(daemon->icmp6fd, daemon->outpacket.iov_base, 
+			   save_counter(0), 0, (struct sockaddr *)&addr, 
+			   sizeof(addr))));
   
 }
 
diff --git a/src/util.c b/src/util.c
index 91d02410b13f..648bc4d4b428 100644
--- a/src/util.c
+++ b/src/util.c
@@ -569,17 +569,27 @@ void bump_maxfd(int fd, int *max)
     *max = fd;
 }
 
-int retry_send(void)
+/* rc is return from sendto and friends.
+   Return 1 if we should retry.
+   Set errno to zero if we succeeded. */
+int retry_send(ssize_t rc)
 {
+  static int retries = 0;
+  struct timespec waiter;
+  
+  if (rc != -1)
+    {
+      retries = 0;
+      errno = 0;
+      return 0;
+    }
+  
   /* Linux kernels can return EAGAIN in perpetuity when calling
      sendmsg() and the relevant interface has gone. Here we loop
      retrying in EAGAIN for 1 second max, to avoid this hanging 
      dnsmasq. */
 
-  static int retries = 0;
-  struct timespec waiter;
-
-   if (errno == EAGAIN || errno == EWOULDBLOCK)
+  if (errno == EAGAIN || errno == EWOULDBLOCK)
      {
        waiter.tv_sec = 0;
        waiter.tv_nsec = 10000;
@@ -587,13 +597,13 @@ int retry_send(void)
        if (retries++ < 1000)
 	 return 1;
      }
-
-   retries = 0;
-   
-   if (errno == EINTR)
-     return 1;
-   
-   return 0;
+  
+  retries = 0;
+  
+  if (errno == EINTR)
+    return 1;
+  
+  return 0;
 }
 
 int read_write(int fd, unsigned char *packet, int size, int rw)
@@ -602,22 +612,21 @@ int read_write(int fd, unsigned char *packet, int size, int rw)
   
   for (done = 0; done < size; done += n)
     {
-    retry:
-      if (rw)
-        n = read(fd, &packet[done], (size_t)(size - done));
-      else
-        n = write(fd, &packet[done], (size_t)(size - done));
-
-      if (n == 0)
-        return 0;
-      else if (n == -1)
-        {
-          if (retry_send() || errno == ENOMEM || errno == ENOBUFS)
-            goto retry;
-          else
-            return 0;
-        }
+      do { 
+	if (rw)
+	  n = read(fd, &packet[done], (size_t)(size - done));
+	else
+	  n = write(fd, &packet[done], (size_t)(size - done));
+	
+	if (n == 0)
+	  return 0;
+	
+      } while (retry_send(n) || errno == ENOMEM || errno == ENOBUFS);
+
+      if (errno != 0)
+	return 0;
     }
+     
   return 1;
 }
 
-- 
2.1.0
Commit	Line	Data
c6ce1e7e MT	1	From ff841ebf5a5d6864ff48571f607c32ce80dbb75a Mon Sep 17 00:00:00 2001
	2	From: Simon Kelley <simon@thekelleys.org.uk>
	3	Date: Wed, 11 Mar 2015 21:36:30 +0000
697b4f04	4	Subject: [PATCH 058/113] Fix boilerplate code for re-running system calls on
c6ce1e7e MT	5	EINTR and EAGAIN etc.
	6
	7	The nasty code with static variable in retry_send() which
	8	avoids looping forever needs to be called on success of the syscall,
	9	to reset the static variable.
	10	---
	11	src/bpf.c \| 2 +-
	12	src/dhcp.c \| 2 +-
	13	src/dhcp6.c \| 6 +++---
	14	src/dnsmasq.c \| 35 +++++++++++++++++----------------
	15	src/dnsmasq.h \| 2 +-
	16	src/forward.c \| 41 ++++++++++++++++++--------------------
	17	src/ipset.c \| 8 ++++----
	18	src/loop.c \| 5 +++--
	19	src/netlink.c \| 8 ++++----
	20	src/radv.c \| 5 +++--
	21	src/util.c \| 63 ++++++++++++++++++++++++++++++++++-------------------------
	22	11 files changed, 93 insertions(+), 84 deletions(-)
	23
	24	diff --git a/src/bpf.c b/src/bpf.c
	25	index 997d87421bed..a066641f969f 100644
	26	--- a/src/bpf.c
	27	+++ b/src/bpf.c
	28	@@ -359,7 +359,7 @@ void send_via_bpf(struct dhcp_packet *mess, size_t len,
	29	iov[3].iov_base = mess;
	30	iov[3].iov_len = len;
	31
	32	- while (writev(daemon->dhcp_raw_fd, iov, 4) == -1 && retry_send());
	33	+ while (retry_send(writev(daemon->dhcp_raw_fd, iov, 4)));
	34	}
	35
	36	#endif /* defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP) */
	37	diff --git a/src/dhcp.c b/src/dhcp.c
	38	index f29be9b489a7..5c3089ab94ff 100644
	39	--- a/src/dhcp.c
	40	+++ b/src/dhcp.c
	41	@@ -443,7 +443,7 @@ void dhcp_packet(time_t now, int pxe_fd)
	42	setsockopt(fd, IPPROTO_IP, IP_BOUND_IF, &iface_index, sizeof(iface_index));
	43	#endif
	44
	45	- while(sendmsg(fd, &msg, 0) == -1 && retry_send());
	46	+ while(retry_send(sendmsg(fd, &msg, 0)));
	47	}
	48
	49	/* check against secondary interface addresses */
	50	diff --git a/src/dhcp6.c b/src/dhcp6.c
	51	index c7144f5fee7c..ee2aa5d3bf3c 100644
	52	--- a/src/dhcp6.c
	53	+++ b/src/dhcp6.c
	54	@@ -225,9 +225,9 @@ void dhcp6_packet(time_t now)
	55	if (port != 0)
	56	{
	57	from.sin6_port = htons(port);
	58	- while (sendto(daemon->dhcp6fd, daemon->outpacket.iov_base, save_counter(0),
	59	- 0, (struct sockaddr *)&from, sizeof(from)) == -1 &&
	60	- retry_send());
	61	+ while (retry_send(sendto(daemon->dhcp6fd, daemon->outpacket.iov_base,
	62	+ save_counter(0), 0, (struct sockaddr *)&from,
	63	+ sizeof(from))));
	64	}
	65	}
	66
	67	diff --git a/src/dnsmasq.c b/src/dnsmasq.c
	68	index f3e5bcffec4f..b784951950d4 100644
69	--- a/src/dnsmasq.c
70	+++ b/src/dnsmasq.c
71	@@ -444,7 +444,7 @@ int main (int argc, char **argv)
72	char *msg;
73
74	/* close our copy of write-end */
75	- close(err_pipe[1]);
76	+ while (retry_send(close(err_pipe[1])));
77
78	/* check for errors after the fork */
79	if (read_event(err_pipe[0], &ev, &msg))
80	@@ -453,7 +453,7 @@ int main (int argc, char **argv)
81	_exit(EC_GOOD);
82	}
83
84	- close(err_pipe[0]);
85	+ while (retry_send(close(err_pipe[0])));
86
87	/* NO calls to die() from here on. */
88
89	@@ -505,10 +505,12 @@ int main (int argc, char **argv)
90	{
91	if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0))
92	err = 1;
93	-
94	- while (!err && close(fd) == -1)
95	- if (!retry_send())
96	- err = 1;
97	+ else
98	+ {
99	+ while (retry_send(close(fd)));
100	+ if (errno != 0)
101	+ err = 1;
102	+ }
103	}
104
105	if (err)
106	@@ -813,7 +815,7 @@ int main (int argc, char **argv)
107
108	/* finished start-up - release original process */
109	if (err_pipe[1] != -1)
110	- close(err_pipe[1]);
111	+ while (retry_send(close(err_pipe[1])));
112
113	if (daemon->port != 0)
114	check_servers();
115	@@ -1319,7 +1321,7 @@ static void async_event(int pipe, time_t now)
116	do {
117	helper_write();
118	} while (!helper_buf_empty() \|\| do_script_run(now));
119	- close(daemon->helperfd);
120	+ while (retry_send(close(daemon->helperfd)));
121	}
122	#endif
123
124	@@ -1544,7 +1546,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
125
126	if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1)
127	{
128	- close(confd);
129	+ while (retry_send(close(confd)));
130	continue;
131	}
132
133	@@ -1609,7 +1611,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
134	if (!client_ok)
135	{
136	shutdown(confd, SHUT_RDWR);
137	- close(confd);
138	+ while (retry_send(close(confd)));
139	}
140	#ifndef NO_FORK
141	else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0)
142	@@ -1624,7 +1626,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
143	break;
144	}
145	}
146	- close(confd);
147	+ while (retry_send(close(confd)));
148
149	/* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */
150	daemon->log_id += TCP_MAX_QUERIES;
151	@@ -1669,7 +1671,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
152	buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns);
153
154	shutdown(confd, SHUT_RDWR);
155	- close(confd);
156	+ while (retry_send(close(confd)));
157
158	if (buff)
159	free(buff);
160	@@ -1678,7 +1680,7 @@ static void check_dns_listeners(fd_set *set, time_t now)
161	if (s->tcpfd != -1)
162	{
163	shutdown(s->tcpfd, SHUT_RDWR);
164	- close(s->tcpfd);
165	+ while (retry_send(close(s->tcpfd)));
166	}
167	#ifndef NO_FORK
168	if (!option_bool(OPT_DEBUG))
169	@@ -1756,9 +1758,8 @@ int icmp_ping(struct in_addr addr)
170	j = (j & 0xffff) + (j >> 16);
171	packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j;
172
173	- while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0,
174	- (struct sockaddr *)&saddr, sizeof(saddr)) == -1 &&
175	- retry_send());
176	+ while (retry_send(sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0,
177	+ (struct sockaddr *)&saddr, sizeof(saddr))));
178
179	for (now = start = dnsmasq_time();
180	difftime(now, start) < (float)PING_WAIT;)
181	@@ -1820,7 +1821,7 @@ int icmp_ping(struct in_addr addr)
182	}
183
184	#if defined(HAVE_LINUX_NETWORK) \|\| defined(HAVE_SOLARIS_NETWORK)
185	- close(fd);
186	+ while (retry_send(close(fd)));
187	#else
188	opt = 1;
189	setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
190	diff --git a/src/dnsmasq.h b/src/dnsmasq.h
191	index fc7259881358..de95d0e875e3 100644
192	--- a/src/dnsmasq.h
193	+++ b/src/dnsmasq.h
194	@@ -1177,7 +1177,7 @@ int is_same_net6(struct in6_addr a, struct in6_addr b, int prefixlen);
195	u64 addr6part(struct in6_addr *addr);
196	void setaddr6part(struct in6_addr *addr, u64 host);
197	#endif
198	-int retry_send(void);
199	+int retry_send(ssize_t rc);
200	void prettyprint_time(char *buf, unsigned int t);
201	int prettyprint_addr(union mysockaddr addr, char buf);
202	int parse_hex(char in, unsigned char out, int maxlen,
203	diff --git a/src/forward.c b/src/forward.c
204	index 438e9fa490b8..7c0fa8da3fdf 100644
205	--- a/src/forward.c
206	+++ b/src/forward.c
207	@@ -103,15 +103,11 @@ int send_from(int fd, int nowild, char *packet, size_t len,
208	#endif
209	}
210
211	- while (sendmsg(fd, &msg, 0) == -1)
212	+ while (retry_send(sendmsg(fd, &msg, 0)));
213	+
214	+ /* If interface is still in DAD, EINVAL results - ignore that. */
215	+ if (errno != 0 && errno != EINVAL)
216	{
217	- if (retry_send())
218	- continue;
219	-
220	- /* If interface is still in DAD, EINVAL results - ignore that. */
221	- if (errno == EINVAL)
222	- break;
223	-
224	my_syslog(LOG_ERR, _("failed to send packet: %s"), strerror(errno));
225	return 0;
226	}
227	@@ -297,9 +293,9 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
228	fd = forward->rfd4->fd;
229	}
230
231	- while (sendto(fd, (char *)header, plen, 0,
232	- &forward->sentto->addr.sa,
233	- sa_len(&forward->sentto->addr)) == -1 && retry_send());
234	+ while (retry_send( sendto(fd, (char *)header, plen, 0,
235	+ &forward->sentto->addr.sa,
236	+ sa_len(&forward->sentto->addr))));
237
238	return 1;
239	}
240	@@ -469,14 +465,12 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
241	#endif
242	}
243
244	- if (sendto(fd, (char *)header, plen, 0,
245	- &start->addr.sa,
246	- sa_len(&start->addr)) == -1)
247	- {
248	- if (retry_send())
249	- continue;
250	- }
251	- else
252	+ if (retry_send(sendto(fd, (char *)header, plen, 0,
253	+ &start->addr.sa,
254	+ sa_len(&start->addr))))
255	+ continue;
256	+
257	+ if (errno == 0)
258	{
259	/* Keep info in case we want to re-send this packet */
260	daemon->srv_save = start;
261	@@ -932,7 +926,9 @@ void reply_query(int fd, int family, time_t now)
262
263	if (fd != -1)
264	{
265	- while (sendto(fd, (char *)header, nn, 0, &server->addr.sa, sa_len(&server->addr)) == -1 && retry_send());
266	+ while (retry_send(sendto(fd, (char *)header, nn, 0,
267	+ &server->addr.sa,
268	+ sa_len(&server->addr))));
269	server->queries++;
270	}
271
272	@@ -2228,8 +2224,9 @@ void resend_query()
273	else
274	return;
275
276	- while(sendto(fd, daemon->packet, daemon->packet_len, 0,
277	- &daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send());
278	+ while(retry_send(sendto(fd, daemon->packet, daemon->packet_len, 0,
279	+ &daemon->srv_save->addr.sa,
280	+ sa_len(&daemon->srv_save->addr))));
281	}
282	}
283
284	diff --git a/src/ipset.c b/src/ipset.c
285	index 8c5b72722371..a315e86bc7f4 100644
286	--- a/src/ipset.c
287	+++ b/src/ipset.c
288	@@ -121,7 +121,6 @@ static int new_add_to_ipset(const char setname, const struct all_addr ipaddr,
289	struct my_nlattr *nested[2];
290	uint8_t proto;
291	int addrsz = INADDRSZ;
292	- ssize_t rc;
293
294	#ifdef HAVE_IPV6
295	if (af == AF_INET6)
296	@@ -162,9 +161,10 @@ static int new_add_to_ipset(const char setname, const struct all_addr ipaddr,
297	nested[1]->nla_len = (void )buffer + NL_ALIGN(nlh->nlmsg_len) - (void )nested[1];
298	nested[0]->nla_len = (void )buffer + NL_ALIGN(nlh->nlmsg_len) - (void )nested[0];
299
300	- while ((rc = sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
301	- (struct sockaddr *)&snl, sizeof(snl))) == -1 && retry_send());
302	- return rc;
303	+ while (retry_send(sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
304	+ (struct sockaddr *)&snl, sizeof(snl))));
305	+
306	+ return errno == 0 ? 0 : -1;
307	}
308
309
310	diff --git a/src/loop.c b/src/loop.c
311	index 565f7d8e58e0..c9ed075670de 100644
312	--- a/src/loop.c
313	+++ b/src/loop.c
314	@@ -45,8 +45,9 @@ void loop_send_probes()
315	fd = rfd->fd;
316	}
317
318	- while (sendto(fd, daemon->packet, len, 0, &serv->addr.sa, sa_len(&serv->addr)) == -1 && retry_send());
319	-
320	+ while (retry_send(sendto(fd, daemon->packet, len, 0,
321	+ &serv->addr.sa, sa_len(&serv->addr))));
322	+
323	free_rfd(rfd);
324	}
325	}
326	diff --git a/src/netlink.c b/src/netlink.c
327	index 10f94db25a14..753784dc20b4 100644
328	--- a/src/netlink.c
329	+++ b/src/netlink.c
330	@@ -169,10 +169,10 @@ int iface_enumerate(int family, void parm, int (callback)())
331	req.g.rtgen_family = family;
332
333	/* Don't block in recvfrom if send fails */
334	- while((len = sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0,
335	- (struct sockaddr *)&addr, sizeof(addr))) == -1 && retry_send());
336	-
337	- if (len == -1)
338	+ while(retry_send(sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0,
339	+ (struct sockaddr *)&addr, sizeof(addr))));
340	+
341	+ if (errno != 0)
342	return 0;
343
344	while (1)
345	diff --git a/src/radv.c b/src/radv.c
346	index 6da125b864ae..d0faddf8684a 100644
347	--- a/src/radv.c
348	+++ b/src/radv.c
349	@@ -479,8 +479,9 @@ static void send_ra(time_t now, int iface, char iface_name, struct in6_addr de
350	setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &iface, sizeof(iface));
351	}
352
353	- while (sendto(daemon->icmp6fd, daemon->outpacket.iov_base, save_counter(0), 0,
354	- (struct sockaddr *)&addr, sizeof(addr)) == -1 && retry_send());
355	+ while (retry_send(sendto(daemon->icmp6fd, daemon->outpacket.iov_base,
356	+ save_counter(0), 0, (struct sockaddr *)&addr,
357	+ sizeof(addr))));
358
359	}
360
361	diff --git a/src/util.c b/src/util.c
362	index 91d02410b13f..648bc4d4b428 100644
363	--- a/src/util.c
364	+++ b/src/util.c
365	@@ -569,17 +569,27 @@ void bump_maxfd(int fd, int *max)
366	*max = fd;
367	}
368
369	-int retry_send(void)
370	+/* rc is return from sendto and friends.
371	+ Return 1 if we should retry.
372	+ Set errno to zero if we succeeded. */
373	+int retry_send(ssize_t rc)
374	{
375	+ static int retries = 0;
376	+ struct timespec waiter;
377	+
378	+ if (rc != -1)
379	+ {
380	+ retries = 0;
381	+ errno = 0;
382	+ return 0;
383	+ }
384	+
385	/* Linux kernels can return EAGAIN in perpetuity when calling
386	sendmsg() and the relevant interface has gone. Here we loop
387	retrying in EAGAIN for 1 second max, to avoid this hanging
388	dnsmasq. */
389
390	- static int retries = 0;
391	- struct timespec waiter;
392	-
393	- if (errno == EAGAIN \|\| errno == EWOULDBLOCK)
394	+ if (errno == EAGAIN \|\| errno == EWOULDBLOCK)
395	{
396	waiter.tv_sec = 0;
397	waiter.tv_nsec = 10000;
398	@@ -587,13 +597,13 @@ int retry_send(void)
399	if (retries++ < 1000)
400	return 1;
401	}
402	-
403	- retries = 0;
404	-
405	- if (errno == EINTR)
406	- return 1;
407	-
408	- return 0;
409	+
410	+ retries = 0;
411	+
412	+ if (errno == EINTR)
413	+ return 1;
414	+
415	+ return 0;
416	}
417
418	int read_write(int fd, unsigned char *packet, int size, int rw)
419	@@ -602,22 +612,21 @@ int read_write(int fd, unsigned char *packet, int size, int rw)
420
421	for (done = 0; done < size; done += n)
422	{
423	- retry:
424	- if (rw)
425	- n = read(fd, &packet[done], (size_t)(size - done));
426	- else
427	- n = write(fd, &packet[done], (size_t)(size - done));
428	-
429	- if (n == 0)
430	- return 0;
431	- else if (n == -1)
432	- {
433	- if (retry_send() \|\| errno == ENOMEM \|\| errno == ENOBUFS)
434	- goto retry;
435	- else
436	- return 0;
437	- }
438	+ do {
439	+ if (rw)
440	+ n = read(fd, &packet[done], (size_t)(size - done));
441	+ else
442	+ n = write(fd, &packet[done], (size_t)(size - done));
443	+
444	+ if (n == 0)
445	+ return 0;
446	+
447	+ } while (retry_send(n) \|\| errno == ENOMEM \|\| errno == ENOBUFS);
448	+
449	+ if (errno != 0)
450	+ return 0;
451	}
452	+
453	return 1;
454	}
455
456	--
457	2.1.0
458