Support domain-search in dhclient(8)

The "domain-search" option (option 119) allows a DHCP server to publish
a list of implicit domain suffixes used during name lookup. This option
is described in RFC 3397.

For instance, if the domain-search option says:
    ".example.org .example.com"
and one wants to resolve "foobar", the resolver will try:
    1. "foobar.example.org"
    2. "foobar.example.com"

The file /etc/resolv.conf is updated with a "search" directive if the
DHCP server provides "domain-search".

A regression test suite is included in this patch under
tools/regression/sbin/dhclient.

PR:		bin/151940
Sponsored by	Yakaz (http://www.yakaz.com)

4 files changed, 405 insertions, 1 deletions

diff --git a/tools/regression/sbin/Makefile b/tools/regression/sbin/Makefile
index 33d158e..623ff62 100644
--- a/tools/regression/sbin/Makefile
+++ b/tools/regression/sbin/Makefile
@@ -1,5 +1,5 @@
 # $FreeBSD$
 
-SUBDIR=	growfs
+SUBDIR=	dhclient growfs
 
 .include <bsd.subdir.mk>
diff --git a/tools/regression/sbin/dhclient/Makefile b/tools/regression/sbin/dhclient/Makefile
new file mode 100644
index 0000000..7de3791
--- /dev/null
+++ b/tools/regression/sbin/dhclient/Makefile
@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+.PATH:	${.CURDIR}/../../../../sbin/dhclient
+
+SRCS=	alloc.c convert.c hash.c options.c tables.c			\
+	fake.c								\
+	option-domain-search.c
+
+CFLAGS+= -I${.CURDIR}/../../../../sbin/dhclient
+LDADD=	-lutil
+
+PROG=	option-domain-search
+
+WARNS?=	2
+
+.include <bsd.prog.mk>
diff --git a/tools/regression/sbin/dhclient/fake.c b/tools/regression/sbin/dhclient/fake.c
new file mode 100644
index 0000000..91d57b6
--- /dev/null
+++ b/tools/regression/sbin/dhclient/fake.c
@@ -0,0 +1,60 @@
+/* $FreeBSD$ */
+
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "dhcpd.h"
+
+extern jmp_buf env;
+
+void
+error(char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+
+	longjmp(env, 1);
+}
+
+int
+warning(char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+
+	return ret;
+}
+
+int
+note(char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+
+	return ret;
+}
+
+void
+bootp(struct packet *packet)
+{
+}
+
+void
+dhcp(struct packet *packet)
+{
+}
diff --git a/tools/regression/sbin/dhclient/option-domain-search.c b/tools/regression/sbin/dhclient/option-domain-search.c
new file mode 100644
index 0000000..b79f9a5
--- /dev/null
+++ b/tools/regression/sbin/dhclient/option-domain-search.c
@@ -0,0 +1,328 @@
+/* $FreeBSD$ */
+
+#include <setjmp.h>
+#include <stdlib.h>
+
+#include "dhcpd.h"
+
+jmp_buf env;
+
+void	expand_domain_search(struct packet *packet);
+
+void
+no_option_present()
+{
+	int ret;
+	struct option_data option;
+	struct packet p;
+
+	option.data = NULL;
+	option.len  = 0;
+	p.options[DHO_DOMAIN_SEARCH] = option;
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (p.options[DHO_DOMAIN_SEARCH].len != 0 ||
+	    p.options[DHO_DOMAIN_SEARCH].data != NULL)
+		abort();
+}
+
+void
+one_domain_valid()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data     = "\007example\003org\0";
+	char *expected = "example.org.";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 13;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (option->len != strlen(expected) ||
+	    strcmp(option->data, expected) != 0)
+		abort();
+
+	free(option->data);
+}
+
+void
+one_domain_truncated1()
+{
+	int ret;
+	struct option_data *option;
+	struct packet p;
+
+	char *data = "\007example\003org";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 12;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+one_domain_truncated2()
+{
+	int ret;
+	struct option_data *option;
+	struct packet p;
+
+	char *data = "\007ex";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 3;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_valid()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data     = "\007example\003org\0\007example\003com\0";
+	char *expected = "example.org. example.com.";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 26;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (option->len != strlen(expected) ||
+	    strcmp(option->data, expected) != 0)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_truncated1()
+{
+	int ret;
+	struct option_data *option;
+	struct packet p;
+
+	char *data = "\007example\003org\0\007example\003com";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 25;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_truncated2()
+{
+	int ret;
+	struct option_data *option;
+	struct packet p;
+
+	char *data = "\007example\003org\0\007ex";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 16;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_compressed()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data     = "\007example\003org\0\006foobar\xc0\x08";
+	char *expected = "example.org. foobar.org.";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 22;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (option->len != strlen(expected) ||
+	    strcmp(option->data, expected) != 0)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_infloop()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data = "\007example\003org\0\006foobar\xc0\x0d";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 22;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_forwardptr()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data = "\007example\003org\xc0\x0d\006foobar\0";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 22;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+two_domains_truncatedptr()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data = "\007example\003org\0\006foobar\xc0";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 21;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (ret != 1)
+		abort();
+
+	free(option->data);
+}
+
+void
+multiple_domains_valid()
+{
+	int ret;
+	struct packet p;
+	struct option_data *option;
+
+	char *data =
+	    "\007example\003org\0\002cl\006foobar\003com\0\002fr\xc0\x10";
+
+	char *expected = "example.org. cl.foobar.com. fr.foobar.com.";
+
+	option = &p.options[DHO_DOMAIN_SEARCH];
+	option->len  = 33;
+	option->data = malloc(option->len);
+	memcpy(option->data, data, option->len);
+
+	ret = setjmp(env);
+	if (ret == 0)
+		expand_domain_search(&p);
+
+	if (option->len != strlen(expected) ||
+	    strcmp(option->data, expected) != 0)
+		abort();
+
+	free(option->data);
+}
+
+int
+main(int argc, char *argv[])
+{
+
+	no_option_present();
+
+	one_domain_valid();
+	one_domain_truncated1();
+	one_domain_truncated2();
+
+	two_domains_valid();
+	two_domains_truncated1();
+	two_domains_truncated2();
+
+	two_domains_compressed();
+	two_domains_infloop();
+	two_domains_forwardptr();
+	two_domains_truncatedptr();
+
+	multiple_domains_valid();
+
+	return (0);
+}