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Fix handling of zero-padding and parse file before sname field (if overloaded, according to the RFC)

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goldsimon 2010-02-02 18:26:40 +00:00
parent 4495d9ef5b
commit 30d69d68e3
1 changed files with 31 additions and 23 deletions
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54
src/core/dhcp.c
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@ -1304,7 +1304,8 @@ dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p)
u16_t options_idx;
u16_t options_idx_max;
struct pbuf *q;
u8_t file_overloaded = 0;
int parse_file_as_options = 0;
int parse_sname_as_options = 0;
/* clear received options */
dhcp_clear_all_options(dhcp);
@ -1353,11 +1354,13 @@ again:
/* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
decode_len = len;
switch(op) {
/* case(DHCP_OPTION_END): handled above */
case(DHCP_OPTION_PAD):
/* special option: no len encoded */
decode_len = len = 0;
/* will be increased below */
offset--;
break;
case(DHCP_OPTION_SUBNET_MASK):
LWIP_ASSERT("len == 4", len == 4);
decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
@ -1433,6 +1436,7 @@ decode_next:
offset -= q->len;
offset_max -= q->len;
q = q->next;
options = (u8_t*)q->payload;
}
}
/* is this an overloaded message? */
@ -1440,38 +1444,42 @@ decode_next:
u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
if (overload == DHCP_OVERLOAD_FILE) {
file_overloaded = 1;
parse_file_as_options = 1;
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
options_idx = DHCP_FILE_OFS;
options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
goto again;
} else if (overload == DHCP_OVERLOAD_SNAME) {
parse_sname_as_options = 1;
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
options_idx = DHCP_SNAME_OFS;
options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
goto again;
} else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
file_overloaded = 1;
parse_sname_as_options = 1;
parse_file_as_options = 1;
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
/* @todo: parse file first and then sname (RFC 2131 ch. 4.1) */
options_idx = DHCP_SNAME_OFS;
options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN + DHCP_FILE_LEN;
goto again;
} else {
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
}
}
#if LWIP_DHCP_BOOTP_FILE
if (!file_overloaded) {
/* only do this for ACK messages */
if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
/* copy bootp file name, don't care for sname (server hostname) */
pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS);
/* make sure the string is really NULL-terminated */
dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
}
if (!parse_file_as_options) {
/* only do this for ACK messages */
if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
/* copy bootp file name, don't care for sname (server hostname) */
pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS);
/* make sure the string is really NULL-terminated */
dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
}
#endif /* LWIP_DHCP_BOOTP_FILE */
}
if (parse_file_as_options) {
/* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
parse_file_as_options = 0;
options_idx = DHCP_FILE_OFS;
options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
goto again;
} else if (parse_sname_as_options) {
parse_sname_as_options = 0;
options_idx = DHCP_SNAME_OFS;
options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
goto again;
}
return ERR_OK;
}