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authorDenis Vlasenko <vda.linux@googlemail.com>2007-11-28 19:23:12 +0000
committerDenis Vlasenko <vda.linux@googlemail.com>2007-11-28 19:23:12 +0000
commit35ff74676b54b1cae5a6324d2517568393fedbc8 (patch)
treeb913eda3005954aec3543cc07d3f86baeeb6429a
parent41f5add965163607b5921aa224b9ba6fa3debc05 (diff)
downloadbusybox-35ff74676b54b1cae5a6324d2517568393fedbc8.tar.gz
dhcpc: let server know we don't like oversized packets.
add TODO comment
-rw-r--r--networking/udhcp/Config.in1
-rw-r--r--networking/udhcp/clientpacket.c3
-rw-r--r--networking/udhcp/files.c6
-rw-r--r--networking/udhcp/options.c68
-rw-r--r--networking/udhcp/options.h4
-rw-r--r--networking/udhcp/script.c23
6 files changed, 58 insertions, 47 deletions
diff --git a/networking/udhcp/Config.in b/networking/udhcp/Config.in
index 1aef69ba7..242a9f3b8 100644
--- a/networking/udhcp/Config.in
+++ b/networking/udhcp/Config.in
@@ -104,3 +104,4 @@ config UDHCPC_SLACK_FOR_BUGGY_SERVERS
seems to confuse maximum allowed UDP packet size with
maximum size of entire IP packet, and sends packets which are
28 bytes too large.
+ Seednet (ISP) VDSL: sends packets 2 bytes too big.
diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c
index 4a5c627f4..406fe340a 100644
--- a/networking/udhcp/clientpacket.c
+++ b/networking/udhcp/clientpacket.c
@@ -96,6 +96,9 @@ int send_discover(uint32_t xid, uint32_t requested)
if (requested)
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
+ /* Explicitly saying that we want RFC-compliant packets helps
+ * some buggy DHCP servers to NOT send bigger packets */
+ add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
add_requests(&packet);
bb_info_msg("Sending discover...");
return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 59a5e4ab2..5026598d7 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -90,7 +90,7 @@ static void attach_option(struct option_set **opt_list,
existing = find_option(*opt_list, option->code);
if (!existing) {
- DEBUG("Attaching option %s to list", option->name);
+ DEBUG("Attaching option %02x to list", option->code);
#if ENABLE_FEATURE_RFC3397
if ((option->flags & TYPE_MASK) == OPTION_STR1035)
@@ -119,7 +119,7 @@ static void attach_option(struct option_set **opt_list,
}
/* add it to an existing option */
- DEBUG("Attaching option %s to existing member of list", option->name);
+ DEBUG("Attaching option %02x to existing member of list", option->code);
if (option->flags & OPTION_LIST) {
#if ENABLE_FEATURE_RFC3397
if ((option->flags & TYPE_MASK) == OPTION_STR1035)
@@ -170,7 +170,7 @@ static int read_opt(const char *const_line, void *arg)
while (1) {
if (!option->code)
return 0;
- if (!strcasecmp(option->name, opt))
+ if (!strcasecmp(option->opt_name, opt))
break;
option++;
}
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index 6744e2ad0..ffc0ed127 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -9,37 +9,42 @@
#include "options.h"
-/* supported options are easily added here */
+/* Supported options are easily added here */
const struct dhcp_option dhcp_options[] = {
- /* name[12] flags code */
- {"subnet", OPTION_IP | OPTION_REQ, 0x01},
- {"timezone", OPTION_S32, 0x02},
- {"router", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03},
- {"timesvr", OPTION_IP | OPTION_LIST, 0x04},
- {"namesvr", OPTION_IP | OPTION_LIST, 0x05},
- {"dns", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06},
- {"logsvr", OPTION_IP | OPTION_LIST, 0x07},
- {"cookiesvr", OPTION_IP | OPTION_LIST, 0x08},
- {"lprsvr", OPTION_IP | OPTION_LIST, 0x09},
- {"hostname", OPTION_STRING | OPTION_REQ, 0x0c},
- {"bootsize", OPTION_U16, 0x0d},
- {"domain", OPTION_STRING | OPTION_LIST | OPTION_REQ, 0x0f},
- {"swapsvr", OPTION_IP, 0x10},
- {"rootpath", OPTION_STRING, 0x11},
- {"ipttl", OPTION_U8, 0x17},
- {"mtu", OPTION_U16, 0x1a},
- {"broadcast", OPTION_IP | OPTION_REQ, 0x1c},
- {"nisdomain", OPTION_STRING | OPTION_REQ, 0x28},
- {"nissrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x29},
- {"ntpsrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a},
- {"wins", OPTION_IP | OPTION_LIST, 0x2c},
- {"requestip", OPTION_IP, 0x32},
- {"lease", OPTION_U32, 0x33},
- {"dhcptype", OPTION_U8, 0x35},
- {"serverid", OPTION_IP, 0x36},
- {"message", OPTION_STRING, 0x38},
- {"vendorclass", OPTION_STRING, 0x3C},
- {"clientid", OPTION_STRING, 0x3D},
+ /* opt_name[12] flags code */
+ {"subnet", OPTION_IP | OPTION_REQ, 0x01}, /* DHCP_SUBNET */
+ {"timezone", OPTION_S32, 0x02}, /* DHCP_TIME_OFFSET */
+ {"router", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03}, /* DHCP_ROUTER */
+ {"timesvr", OPTION_IP | OPTION_LIST, 0x04}, /* DHCP_TIME_SERVER */
+ {"namesvr", OPTION_IP | OPTION_LIST, 0x05}, /* DHCP_NAME_SERVER */
+ {"dns", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06}, /* DHCP_DNS_SERVER */
+ {"logsvr", OPTION_IP | OPTION_LIST, 0x07}, /* DHCP_LOG_SERVER */
+ {"cookiesvr", OPTION_IP | OPTION_LIST, 0x08}, /* DHCP_COOKIE_SERVER */
+ {"lprsvr", OPTION_IP | OPTION_LIST, 0x09}, /* DHCP_LPR_SERVER */
+ {"hostname", OPTION_STRING | OPTION_REQ, 0x0c}, /* DHCP_HOST_NAME */
+ {"bootsize", OPTION_U16, 0x0d}, /* DHCP_BOOT_SIZE */
+ {"domain", OPTION_STRING | OPTION_LIST | OPTION_REQ, 0x0f}, /* DHCP_DOMAIN_NAME */
+ {"swapsvr", OPTION_IP, 0x10}, /* DHCP_SWAP_SERVER */
+ {"rootpath", OPTION_STRING, 0x11}, /* DHCP_ROOT_PATH */
+ {"ipttl", OPTION_U8, 0x17}, /* DHCP_IP_TTL */
+ {"mtu", OPTION_U16, 0x1a}, /* DHCP_MTU */
+ {"broadcast", OPTION_IP | OPTION_REQ, 0x1c}, /* DHCP_BROADCAST */
+ {"nisdomain", OPTION_STRING | OPTION_REQ, 0x28}, /* DHCP_NTP_SERVER */
+ {"nissrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x29}, /* DHCP_WINS_SERVER */
+ {"ntpsrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a}, /* DHCP_REQUESTED_IP */
+ {"wins", OPTION_IP | OPTION_LIST, 0x2c}, /* DHCP_LEASE_TIME */
+ {"requestip", OPTION_IP, 0x32}, /* DHCP_OPTION_OVER */
+ {"lease", OPTION_U32, 0x33}, /* DHCP_MESSAGE_TYPE */
+ {"dhcptype", OPTION_U8, 0x35}, /* DHCP_SERVER_ID */
+ {"serverid", OPTION_IP, 0x36}, /* DHCP_PARAM_REQ */
+ {"message", OPTION_STRING, 0x38}, /* DHCP_MESSAGE */
+// TODO: 1) some options should not be parsed & passed to script -
+// maxsize sure should not, since it cannot appear in server responses!
+// grep for opt_name is fix the mess.
+// 2) Using fixed-sized char[] vector wastes space.
+ {"maxsize", OPTION_U16, 0x39}, /* DHCP_MAX_SIZE */
+ {"vendorclass", OPTION_STRING, 0x3C}, /* DHCP_VENDOR */
+ {"clientid", OPTION_STRING, 0x3D}, /* DHCP_CLIENT_ID */
{"tftp", OPTION_STRING, 0x42},
{"bootfile", OPTION_STRING, 0x43},
{"userclass", OPTION_STRING, 0x4D},
@@ -48,9 +53,10 @@ const struct dhcp_option dhcp_options[] = {
#endif
/* MSIE's "Web Proxy Autodiscovery Protocol" support */
{"wpad", OPTION_STRING, 0xfc},
- {"", 0x00, 0x00}
+ {} /* zero-padded terminating entry */
};
+
/* Lengths of the different option types */
const unsigned char option_lengths[] ALIGN1 = {
[OPTION_IP] = 4,
diff --git a/networking/udhcp/options.h b/networking/udhcp/options.h
index 33a968ce9..4bf73a17e 100644
--- a/networking/udhcp/options.h
+++ b/networking/udhcp/options.h
@@ -33,6 +33,7 @@ enum {
#define DHCP_MAGIC 0x63825363
+
/* DHCP option codes (partial list) */
#define DHCP_PADDING 0x00
#define DHCP_SUBNET 0x01
@@ -67,7 +68,6 @@ enum {
#define DHCP_VENDOR 0x3c
#define DHCP_CLIENT_ID 0x3d
#define DHCP_FQDN 0x51
-
#define DHCP_END 0xFF
@@ -98,7 +98,7 @@ enum {
#define OPT_DATA 2
struct dhcp_option {
- char name[12];
+ char opt_name[12];
char flags;
uint8_t code;
};
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index 68de358e5..33d96e687 100644
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -44,14 +44,15 @@ static int sprintip(char *dest, const char *pre, const uint8_t *ip)
/* really simple implementation, just count the bits */
-static int mton(struct in_addr *mask)
+static int mton(uint32_t mask)
{
- int i;
- unsigned long bits = ntohl(mask->s_addr);
- /* too bad one can't check the carry bit, etc in c bit
- * shifting */
- for (i = 0; i < 32 && !((bits >> i) & 1); i++);
- return 32 - i;
+ int i = 0;
+ mask = ntohl(mask); /* 111110000-like bit pattern */
+ while (mask) {
+ i++;
+ mask <<= 1;
+ }
+ return i;
}
@@ -69,8 +70,8 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
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);
+ dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->opt_name) + 2);
+ dest += sprintf(ret, "%s=", type_p->opt_name);
for (;;) {
switch (type) {
@@ -133,7 +134,6 @@ static char **fill_envp(struct dhcpMessage *packet)
char **envp;
char *var;
uint8_t *temp;
- struct in_addr subnet;
char over = 0;
if (packet) {
@@ -179,8 +179,9 @@ static char **fill_envp(struct dhcpMessage *packet)
/* Fill in a subnet bits option for things like /24 */
if (dhcp_options[i].code == DHCP_SUBNET) {
+ uint32_t subnet;
memcpy(&subnet, temp, 4);
- envp[j++] = xasprintf("mask=%d", mton(&subnet));
+ envp[j++] = xasprintf("mask=%d", mton(subnet));
}
}
if (packet->siaddr) {