[Dnsmasq-discuss] [PATCH] Change read_leases() to skip invalid entries

[Brian Haley]

There's no reason to stop reading the existing lease file
when dnsmasq is started and an invalid entry is found, it
can just be ignored.  This was fallout from an Openstack
bug where the file was being written incorrectly with []
around IPv6 addresses.
---
  src/lease.c | 18 +++++++++++++-----
  1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/lease.c b/src/lease.c
index 3514e44..a415513 100644
--- a/src/lease.c
+++ b/src/lease.c
@@ -60,7 +60,12 @@ static int read_leases(time_t now, FILE *leasestream)
  	
  	if (fscanf(leasestream, " %64s %255s %764s",
  		   daemon->namebuff, daemon->dhcp_buff, daemon->packet) != 3)
-	  return 0;
+	  {
+	    my_syslog(MS_DHCP | LOG_WARNING, _("ignoring invalid line in lease database: %s %s %s %s ..."),
+		      daemon->dhcp_buff3, daemon->dhcp_buff2,
+		      daemon->namebuff, daemon->dhcp_buff);
+	    continue;
+	  }
  	
  	if (inet_pton(AF_INET, daemon->namebuff, &addr.addr4))
  	  {
@@ -92,7 +97,12 @@ static int read_leases(time_t now, FILE *leasestream)
  	  }
  #endif
  	else
-	  return 0;
+	  {
+	    my_syslog(MS_DHCP | LOG_WARNING, _("ignoring invalid line in lease database, bad address: %s %s %s %s ..."),
+		      daemon->dhcp_buff3, daemon->dhcp_buff2,
+		      daemon->namebuff, daemon->dhcp_buff);
+	    continue;
+	  }
  
  	if (!lease)
  	  die (_("too many stored leases"), NULL, EC_MISC);
@@ -172,9 +182,7 @@ void lease_init(time_t now)
    if (leasestream)
      {
        if (!read_leases(now, leasestream))
-	my_syslog(MS_DHCP | LOG_ERR, _("failed to parse lease database, invalid line: %s %s %s %s ..."),
-		  daemon->dhcp_buff3, daemon->dhcp_buff2,
-		  daemon->namebuff, daemon->dhcp_buff);
+	my_syslog(MS_DHCP | LOG_ERR, _("failed to parse lease database cleanly"));
  
        if (ferror(leasestream))
  	die(_("failed to read lease file %s: %s"), daemon->lease_file, EC_FILE);
-- 
2.7.4