164 lines
6.5 KiB
Diff
164 lines
6.5 KiB
Diff
--- a/networking/udhcp/common.c
|
|
+++ b/networking/udhcp/common.c
|
|
@@ -29,16 +29,16 @@ const struct dhcp_optflag dhcp_optflags[
|
|
// { OPTION_IP | OPTION_LIST , 0x07 }, /* DHCP_LOG_SERVER */
|
|
// { OPTION_IP | OPTION_LIST , 0x08 }, /* DHCP_COOKIE_SERVER */
|
|
{ OPTION_IP | OPTION_LIST , 0x09 }, /* DHCP_LPR_SERVER */
|
|
- { OPTION_STRING | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
|
|
+ { OPTION_STRING_HOST | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
|
|
{ OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
|
|
- { OPTION_STRING | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME */
|
|
+ { OPTION_STRING_HOST | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME */
|
|
{ OPTION_IP , 0x10 }, /* DHCP_SWAP_SERVER */
|
|
{ OPTION_STRING , 0x11 }, /* DHCP_ROOT_PATH */
|
|
{ OPTION_U8 , 0x17 }, /* DHCP_IP_TTL */
|
|
{ OPTION_U16 , 0x1a }, /* DHCP_MTU */
|
|
{ OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
|
|
{ OPTION_IP_PAIR | OPTION_LIST , 0x21 }, /* DHCP_ROUTES */
|
|
- { OPTION_STRING , 0x28 }, /* DHCP_NIS_DOMAIN */
|
|
+ { OPTION_STRING_HOST , 0x28 }, /* DHCP_NIS_DOMAIN */
|
|
{ OPTION_IP | OPTION_LIST , 0x29 }, /* DHCP_NIS_SERVER */
|
|
{ OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
|
|
{ OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
|
|
@@ -46,7 +46,7 @@ const struct dhcp_optflag dhcp_optflags[
|
|
{ OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
|
|
{ OPTION_STRING , 0x38 }, /* DHCP_ERR_MESSAGE */
|
|
//TODO: must be combined with 'sname' and 'file' handling:
|
|
- { OPTION_STRING , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
|
|
+ { OPTION_STRING_HOST , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
|
|
{ OPTION_STRING , 0x43 }, /* DHCP_BOOT_FILE */
|
|
//TODO: not a string, but a set of LASCII strings:
|
|
// { OPTION_STRING , 0x4D }, /* DHCP_USER_CLASS */
|
|
@@ -143,6 +143,7 @@ const uint8_t dhcp_option_lengths[] ALIG
|
|
[OPTION_IP_PAIR] = 8,
|
|
// [OPTION_BOOLEAN] = 1,
|
|
[OPTION_STRING] = 1, /* ignored by udhcp_str2optset */
|
|
+ [OPTION_STRING_HOST] = 1, /* ignored by udhcp_str2optset */
|
|
#if ENABLE_FEATURE_UDHCP_RFC3397
|
|
[OPTION_DNS_STRING] = 1, /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
|
|
[OPTION_SIP_SERVERS] = 1,
|
|
@@ -411,7 +412,9 @@ static NOINLINE void attach_option(
|
|
/* actually 255 is ok too, but adding a space can overlow it */
|
|
|
|
existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
|
|
- if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING) {
|
|
+ if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
|
|
+ || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
|
|
+ ) {
|
|
/* add space separator between STRING options in a list */
|
|
existing->data[OPT_DATA + old_len] = ' ';
|
|
old_len++;
|
|
@@ -475,6 +478,7 @@ int FAST_FUNC udhcp_str2optset(const cha
|
|
retval = udhcp_str2nip(val, buffer + 4);
|
|
break;
|
|
case OPTION_STRING:
|
|
+ case OPTION_STRING_HOST:
|
|
#if ENABLE_FEATURE_UDHCP_RFC3397
|
|
case OPTION_DNS_STRING:
|
|
#endif
|
|
--- a/networking/udhcp/common.h
|
|
+++ b/networking/udhcp/common.h
|
|
@@ -80,6 +80,9 @@ enum {
|
|
OPTION_IP = 1,
|
|
OPTION_IP_PAIR,
|
|
OPTION_STRING,
|
|
+ /* Opts of STRING_HOST type will be sanitized before they are passed
|
|
+ * to udhcpc script's environment: */
|
|
+ OPTION_STRING_HOST,
|
|
// OPTION_BOOLEAN,
|
|
OPTION_U8,
|
|
OPTION_U16,
|
|
--- a/networking/udhcp/dhcpc.c
|
|
+++ b/networking/udhcp/dhcpc.c
|
|
@@ -101,6 +101,7 @@ static const uint8_t len_of_option_as_st
|
|
[OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
|
|
[OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
|
|
[OPTION_STRING ] = 1,
|
|
+ [OPTION_STRING_HOST ] = 1,
|
|
#if ENABLE_FEATURE_UDHCP_RFC3397
|
|
[OPTION_DNS_STRING ] = 1, /* unused */
|
|
/* Hmmm, this severely overestimates size if SIP_SERVERS option
|
|
@@ -135,6 +136,63 @@ static int mton(uint32_t mask)
|
|
return i;
|
|
}
|
|
|
|
+/* Check if a given label represents a valid DNS label
|
|
+ * Return pointer to the first character after the label upon success,
|
|
+ * NULL otherwise.
|
|
+ * See RFC1035, 2.3.1
|
|
+ */
|
|
+/* We don't need to be particularly anal. For example, allowing _, hyphen
|
|
+ * at the end, or leading and trailing dots would be ok, since it
|
|
+ * can't be used for attacks. (Leading hyphen can be, if someone uses
|
|
+ * cmd "$hostname"
|
|
+ * in the script: then hostname may be treated as an option)
|
|
+ */
|
|
+static const char *valid_domain_label(const char *label)
|
|
+{
|
|
+ unsigned char ch;
|
|
+ unsigned pos = 0;
|
|
+
|
|
+ for (;;) {
|
|
+ ch = *label;
|
|
+ if ((ch|0x20) < 'a' || (ch|0x20) > 'z') {
|
|
+ if (pos == 0) {
|
|
+ /* label must begin with letter */
|
|
+ return NULL;
|
|
+ }
|
|
+ if (ch < '0' || ch > '9') {
|
|
+ if (ch == '\0' || ch == '.')
|
|
+ return label;
|
|
+ /* DNS allows only '-', but we are more permissive */
|
|
+ if (ch != '-' && ch != '_')
|
|
+ return NULL;
|
|
+ }
|
|
+ }
|
|
+ label++;
|
|
+ pos++;
|
|
+ //Do we want this?
|
|
+ //if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */
|
|
+ // return NULL;
|
|
+ }
|
|
+}
|
|
+
|
|
+/* Check if a given name represents a valid DNS name */
|
|
+/* See RFC1035, 2.3.1 */
|
|
+static int good_hostname(const char *name)
|
|
+{
|
|
+ //const char *start = name;
|
|
+
|
|
+ for (;;) {
|
|
+ name = valid_domain_label(name);
|
|
+ if (!name)
|
|
+ return 0;
|
|
+ if (!name[0])
|
|
+ return 1;
|
|
+ //Do we want this?
|
|
+ //return ((name - start) < 1025); /* NS_MAXDNAME */
|
|
+ name++;
|
|
+ }
|
|
+}
|
|
+
|
|
/* Create "opt_name=opt_value" string */
|
|
static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
|
|
{
|
|
@@ -185,8 +243,11 @@ static NOINLINE char *xmalloc_optname_op
|
|
break;
|
|
}
|
|
case OPTION_STRING:
|
|
+ case OPTION_STRING_HOST:
|
|
memcpy(dest, option, len);
|
|
dest[len] = '\0';
|
|
+ if (type == OPTION_STRING_HOST && !good_hostname(dest))
|
|
+ safe_strncpy(dest, "bad", len);
|
|
return ret; /* Short circuit this case */
|
|
case OPTION_STATIC_ROUTES: {
|
|
/* Option binary format:
|
|
@@ -314,6 +375,7 @@ static char **fill_envp(struct dhcp_pack
|
|
/* +1 element for each option, +2 for subnet option: */
|
|
if (packet) {
|
|
/* note: do not search for "pad" (0) and "end" (255) options */
|
|
+//TODO: change logic to scan packet _once_
|
|
for (i = 1; i < 255; i++) {
|
|
temp = udhcp_get_option(packet, i);
|
|
if (temp) {
|