From 5066473d411d6a474af3393d1b62a58ee3313861 Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Tue, 27 Feb 2007 21:15:08 +0000
Subject: [PATCH] udhcp: optionally support RFC3397 (by Gabriel L. Somlo
<somlo@cmu.edu>)
---
networking/udhcp/Config.in | 8 ++++++++
networking/udhcp/Kbuild | 19 ++++++++++---------
networking/udhcp/files.c | 23 +++++++++++++++++++++++
networking/udhcp/options.c | 8 +++++++-
networking/udhcp/options.h | 7 +++++++
networking/udhcp/script.c | 33 ++++++++++++++++++++++-----------
6 files changed, 77 insertions(+), 21 deletions(-)
diff --git a/networking/udhcp/Config.in b/networking/udhcp/Config.in
index f633473eb..9dd02c497 100644
--- a/networking/udhcp/Config.in
+++ b/networking/udhcp/Config.in
@@ -65,3 +65,11 @@ config FEATURE_UDHCP_DEBUG
the background.
See http://udhcp.busybox.net for further details.
+
+config FEATURE_RFC3397
+ bool "Support for RFC3397 domain search (experimental)"
+ default n
+ depends on APP_UDHCPD || APP_UDHCPC
+ help
+ If selected, both client and server will support passing of domain
+ search lists via option 119, specified in RFC3397.
diff --git a/networking/udhcp/Kbuild b/networking/udhcp/Kbuild
index dc2c01f61..57d2511f0 100644
--- a/networking/udhcp/Kbuild
+++ b/networking/udhcp/Kbuild
@@ -6,13 +6,14 @@
#
lib-y:=
-lib-$(CONFIG_APP_UDHCPC) += common.o options.o packet.o pidfile.o \
- signalpipe.o socket.o
-lib-$(CONFIG_APP_UDHCPD) += common.o options.o packet.o pidfile.o \
- signalpipe.o socket.o
-lib-$(CONFIG_APP_UDHCPC) += dhcpc.o clientpacket.o clientsocket.o \
- script.o
-lib-$(CONFIG_APP_UDHCPD) += dhcpd.o arpping.o files.o leases.o \
- serverpacket.o static_leases.o
-lib-$(CONFIG_APP_DUMPLEASES) += dumpleases.o
+lib-$(CONFIG_APP_UDHCPC) += common.o options.o packet.o pidfile.o \
+ signalpipe.o socket.o
+lib-$(CONFIG_APP_UDHCPD) += common.o options.o packet.o pidfile.o \
+ signalpipe.o socket.o
+lib-$(CONFIG_APP_UDHCPC) += dhcpc.o clientpacket.o clientsocket.o \
+ script.o
+lib-$(CONFIG_APP_UDHCPD) += dhcpd.o arpping.o files.o leases.o \
+ serverpacket.o static_leases.o
+lib-$(CONFIG_APP_DUMPLEASES) += dumpleases.o
lib-$(CONFIG_APP_DHCPRELAY) += dhcprelay.o
+lib-$(CONFIG_FEATURE_RFC3397) += domain_codec.o
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index e35f50a17..ab6f4a3e4 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -104,6 +104,12 @@ static void attach_option(struct option_set **opt_list,
if (!existing) {
DEBUG("Attaching option %s to list", option->name);
+#if ENABLE_FEATURE_RFC3397
+ if ((option->flags & TYPE_MASK) == OPTION_STR1035)
+ /* reuse buffer and length for RFC1035-formatted string */
+ buffer = dname_enc(NULL, 0, buffer, &length);
+#endif
+
/* make a new option */
new = xmalloc(sizeof(struct option_set));
new->data = xmalloc(length + 2);
@@ -117,12 +123,22 @@ static void attach_option(struct option_set **opt_list,
new->next = *curr;
*curr = new;
+#if ENABLE_FEATURE_RFC3397
+ if ((option->flags & TYPE_MASK) == OPTION_STR1035 && buffer != NULL)
+ free(buffer);
+#endif
return;
}
/* add it to an existing option */
DEBUG("Attaching option %s to existing member of list", option->name);
if (option->flags & OPTION_LIST) {
+#if ENABLE_FEATURE_RFC3397
+ if ((option->flags & TYPE_MASK) == OPTION_STR1035)
+ /* reuse buffer and length for RFC1035-formatted string */
+ buffer = dname_enc(existing->data + 2,
+ existing->data[OPT_LEN], buffer, &length);
+#endif
if (existing->data[OPT_LEN] + length <= 255) {
existing->data = xrealloc(existing->data,
existing->data[OPT_LEN] + length + 3);
@@ -137,6 +153,10 @@ static void attach_option(struct option_set **opt_list,
memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
existing->data[OPT_LEN] += length;
} /* else, ignore the data, we could put this in a second option in the future */
+#if ENABLE_FEATURE_RFC3397
+ if ((option->flags & TYPE_MASK) == OPTION_STR1035 && buffer != NULL)
+ free(buffer);
+#endif
} /* else, ignore the new data */
}
@@ -183,6 +203,9 @@ static int read_opt(const char *const_line, void *arg)
if (retval) retval = read_ip(val, buffer + 4);
break;
case OPTION_STRING:
+#if ENABLE_FEATURE_RFC3397
+ case OPTION_STR1035:
+#endif
length = strlen(val);
if (length > 0) {
if (length > 254) length = 254;
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index bda6efc7e..a58adb9a9 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -11,7 +11,7 @@
/* supported options are easily added here */
const struct dhcp_option dhcp_options[] = {
- /* name[10] flags code */
+ /* name[12] flags code */
{"subnet", OPTION_IP | OPTION_REQ, 0x01},
{"timezone", OPTION_S32, 0x02},
{"router", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03},
@@ -43,6 +43,9 @@ const struct dhcp_option dhcp_options[] = {
{"tftp", OPTION_STRING, 0x42},
{"bootfile", OPTION_STRING, 0x43},
{"userclass", OPTION_STRING, 0x4D},
+#if ENABLE_FEATURE_RFC3397
+ {"search", OPTION_STR1035 | OPTION_LIST | OPTION_REQ, 0x77},
+#endif
/* MSIE's "Web Proxy Autodiscovery Protocol" support */
{"wpad", OPTION_STRING, 0xfc},
{"", 0x00, 0x00}
@@ -54,6 +57,9 @@ const unsigned char option_lengths[] = {
[OPTION_IP_PAIR] = 8,
[OPTION_BOOLEAN] = 1,
[OPTION_STRING] = 1,
+#if ENABLE_FEATURE_RFC3397
+ [OPTION_STR1035] = 1,
+#endif
[OPTION_U8] = 1,
[OPTION_U16] = 2,
[OPTION_S16] = 2,
diff --git a/networking/udhcp/options.h b/networking/udhcp/options.h
index 588504e5d..11f013fd4 100644
--- a/networking/udhcp/options.h
+++ b/networking/udhcp/options.h
@@ -9,6 +9,9 @@ enum {
OPTION_IP=1,
OPTION_IP_PAIR,
OPTION_STRING,
+#if ENABLE_FEATURE_RFC3397
+ OPTION_STR1035, /* RFC1035 compressed domain name list */
+#endif
OPTION_BOOLEAN,
OPTION_U8,
OPTION_U16,
@@ -33,5 +36,9 @@ uint8_t *get_option(struct dhcpMessage *packet, int code);
int end_option(uint8_t *optionptr);
int add_option_string(uint8_t *optionptr, uint8_t *string);
int add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data);
+#if ENABLE_FEATURE_RFC3397
+char *dname_dec(const uint8_t *cstr, int clen, const char *pre);
+uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen);
+#endif
#endif
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index d2b0bb05b..dc8ff7a1c 100644
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -19,6 +19,9 @@ static const int max_option_length[] = {
[OPTION_IP] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
[OPTION_STRING] = 1,
+#if ENABLE_FEATURE_RFC3397
+ [OPTION_STR1035] = 1,
+#endif
[OPTION_BOOLEAN] = sizeof("yes "),
[OPTION_U8] = sizeof("255 "),
[OPTION_U16] = sizeof("65535 "),
@@ -53,21 +56,23 @@ static int mton(struct in_addr *mask)
}
-/* Fill dest with the text of option 'option'. */
-static void fill_options(char *dest, uint8_t *option,
- const struct dhcp_option *type_p)
+/* Allocate and fill with the text of option 'option'. */
+static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
{
- int type, optlen;
+ int len, type, optlen;
uint16_t val_u16;
int16_t val_s16;
uint32_t val_u32;
int32_t val_s32;
- int len = option[OPT_LEN - 2];
-
- dest += sprintf(dest, "%s=", type_p->name);
+ char *dest, *ret;
+ len = option[OPT_LEN - 2];
type = type_p->flags & TYPE_MASK;
optlen = option_lengths[type];
+
+ dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->name) + 2);
+ dest += sprintf(ret, "%s=", type_p->name);
+
for (;;) {
switch (type) {
case OPTION_IP_PAIR:
@@ -103,13 +108,21 @@ static void fill_options(char *dest, uint8_t *option,
case OPTION_STRING:
memcpy(dest, option, len);
dest[len] = '\0';
- return; /* Short circuit this case */
+ return ret; /* Short circuit this case */
+#if ENABLE_FEATURE_RFC3397
+ case OPTION_STR1035:
+ /* unpack option into dest; use ret for prefix (i.e., "optname=") */
+ dest = dname_dec(option, len, ret);
+ free(ret);
+ return dest;
+#endif
}
option += optlen;
len -= optlen;
if (len <= 0) break;
dest += sprintf(dest, " ");
}
+ return ret;
}
@@ -155,9 +168,7 @@ static char **fill_envp(struct dhcpMessage *packet)
temp = get_option(packet, dhcp_options[i].code);
if (!temp)
continue;
- envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],
- dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);
- fill_options(envp[j++], temp, &dhcp_options[i]);
+ envp[j++] = alloc_fill_opts(temp, &dhcp_options[i]);
/* Fill in a subnet bits option for things like /24 */
if (dhcp_options[i].code == DHCP_SUBNET) {