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dhcpc: let server know we don't like oversized packets.

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add TODO comment
This commit is contained in:
Denis Vlasenko 2007-11-28 19:23:12 +00:00
parent 41f5add965
commit 35ff74676b
6 changed files with 58 additions and 47 deletions
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1
networking/udhcp/Config.in
View File

@ -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.

3
networking/udhcp/clientpacket.c
View File

@ -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,

6
networking/udhcp/files.c
View File

@ -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++;
}

68
networking/udhcp/options.c
View File

@ -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,

4
networking/udhcp/options.h
View File

@ -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;
};

23
networking/udhcp/script.c
View File

@ -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) {