--- /dev/null
+From bd08ae67f9a0cae2ce15be885254cad9449d4551 Mon Sep 17 00:00:00 2001
+From: Simon Kelley <simon@thekelleys.org.uk>
+Date: Fri, 19 Apr 2013 10:22:06 +0100
+Subject: [PATCH] Allow option number zero in encapsulated DHCP options.
+
+
+Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
+---
+ src/dhcp-common.c | 6 +++---
+ src/dnsmasq.h | 4 ++--
+ src/option.c | 33 ++++++++++++++++++++-------------
+ 3 files changed, 25 insertions(+), 18 deletions(-)
+
+diff --git a/src/dhcp-common.c b/src/dhcp-common.c
+index f4fd088..8de4268 100644
+--- a/src/dhcp-common.c
++++ b/src/dhcp-common.c
+@@ -512,7 +512,7 @@ void display_opts6(void)
+ }
+ #endif
+
+-u16 lookup_dhcp_opt(int prot, char *name)
++int lookup_dhcp_opt(int prot, char *name)
+ {
+ const struct opttab_t *t;
+ int i;
+@@ -528,10 +528,10 @@ u16 lookup_dhcp_opt(int prot, char *name)
+ if (strcasecmp(t[i].name, name) == 0)
+ return t[i].val;
+
+- return 0;
++ return -1;
+ }
+
+-u16 lookup_dhcp_len(int prot, u16 val)
++int lookup_dhcp_len(int prot, int val)
+ {
+ const struct opttab_t *t;
+ int i;
+diff --git a/src/dnsmasq.h b/src/dnsmasq.h
+index 69ae7a7..41e2798 100644
+--- a/src/dnsmasq.h
++++ b/src/dnsmasq.h
+@@ -1216,8 +1216,8 @@ void log_tags(struct dhcp_netid *netid, u32 xid);
+ int match_bytes(struct dhcp_opt *o, unsigned char *p, int len);
+ void dhcp_update_configs(struct dhcp_config *configs);
+ void display_opts(void);
+-u16 lookup_dhcp_opt(int prot, char *name);
+-u16 lookup_dhcp_len(int prot, u16 val);
++int lookup_dhcp_opt(int prot, char *name);
++int lookup_dhcp_len(int prot, int val);
+ char *option_string(int prot, unsigned int opt, unsigned char *val,
+ int opt_len, char *buf, int buf_len);
+ #ifdef HAVE_LINUX_NETWORK
+diff --git a/src/option.c b/src/option.c
+index b2596ec..2a61017 100644
+--- a/src/option.c
++++ b/src/option.c
+@@ -750,6 +750,7 @@ static int parse_dhcp_opt(char *errstr, char *arg, int flags)
+ struct dhcp_netid *np = NULL;
+ u16 opt_len = 0;
+ int is6 = 0;
++ int option_ok = 0;
+
+ new->len = 0;
+ new->flags = flags;
+@@ -769,16 +770,19 @@ static int parse_dhcp_opt(char *errstr, char *arg, int flags)
+ {
+ new->opt = atoi(arg);
+ opt_len = 0;
++ option_ok = 1;
+ break;
+ }
+
+ if (strstr(arg, "option:") == arg)
+ {
+- new->opt = lookup_dhcp_opt(AF_INET, arg+7);
+- opt_len = lookup_dhcp_len(AF_INET, new->opt);
+- /* option:<optname> must follow tag and vendor string. */
+- if ((opt_len & OT_INTERNAL) && flags != DHOPT_MATCH)
+- new->opt = 0;
++ if ((new->opt = lookup_dhcp_opt(AF_INET, arg+7)) != -1)
++ {
++ opt_len = lookup_dhcp_len(AF_INET, new->opt);
++ /* option:<optname> must follow tag and vendor string. */
++ if (!(opt_len & OT_INTERNAL) || flags == DHOPT_MATCH)
++ option_ok = 1;
++ }
+ break;
+ }
+ #ifdef HAVE_DHCP6
+@@ -792,13 +796,16 @@ static int parse_dhcp_opt(char *errstr, char *arg, int flags)
+ {
+ new->opt = atoi(arg+8);
+ opt_len = 0;
++ option_ok = 1;
+ }
+ else
+ {
+- new->opt = lookup_dhcp_opt(AF_INET6, arg+8);
+- opt_len = lookup_dhcp_len(AF_INET6, new->opt);
+- if ((opt_len & OT_INTERNAL) && flags != DHOPT_MATCH)
+- new->opt = 0;
++ if ((new->opt = lookup_dhcp_opt(AF_INET6, arg+8)) != -1)
++ {
++ opt_len = lookup_dhcp_len(AF_INET6, new->opt);
++ if (!(opt_len & OT_INTERNAL) || flags == DHOPT_MATCH)
++ option_ok = 1;
++ }
+ }
+ /* option6:<opt>|<optname> must follow tag and vendor string. */
+ is6 = 1;
+@@ -821,7 +828,7 @@ static int parse_dhcp_opt(char *errstr, char *arg, int flags)
+ new->flags |= DHOPT_RFC3925;
+ if (flags == DHOPT_MATCH)
+ {
+- new->opt = 1; /* avoid error below */
++ option_ok = 1;
+ break;
+ }
+ }
+@@ -848,16 +855,16 @@ static int parse_dhcp_opt(char *errstr, char *arg, int flags)
+
+ if (opt_len == 0 &&
+ !(new->flags & DHOPT_RFC3925))
+- opt_len = lookup_dhcp_len(AF_INET6 ,new->opt);
++ opt_len = lookup_dhcp_len(AF_INET6, new->opt);
+ }
+ else
+ #endif
+ if (opt_len == 0 &&
+ !(new->flags & (DHOPT_VENDOR | DHOPT_ENCAPSULATE | DHOPT_RFC3925)))
+- opt_len = lookup_dhcp_len(AF_INET ,new->opt);
++ opt_len = lookup_dhcp_len(AF_INET, new->opt);
+
+ /* option may be missing with rfc3925 match */
+- if (new->opt == 0)
++ if (!option_ok)
+ ret_err(_("bad dhcp-option"));
+
+ if (comma)
+--
+1.8.1.5