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

add TODO comment

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) {