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| author | Denys Vlasenko | 2011-12-08 16:41:05 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2011-12-08 16:41:05 +0100 |
| commit | 7280d2017d8075267a12e469983e38277dcf0374 (patch) | |
| tree | 3a6bd5c562b04dfadeb72ba7f599db66026977f1 /networking/udhcp/common.c | |
| parent | 53782d9221c854be057edfc4e847ea13717dfece (diff) | |
| download | busybox-7280d2017d8075267a12e469983e38277dcf0374.zip busybox-7280d2017d8075267a12e469983e38277dcf0374.tar.gz | |
udhcpc: sanitize hostnames in incoming packets. Closes 3979.
The following options are replaced with string "bad" if they
contain malformed hostname:
HOST_NAME, DOMAIN_NAME, NIS_DOMAIN, TFTP_SERVER_NAME
function old new delta
xmalloc_optname_optval 850 888 +38
attach_option 440 443 +3
len_of_option_as_string 13 14 +1
dhcp_option_lengths 13 14 +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 43/0) Total: 43 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking/udhcp/common.c')
| -rw-r--r-- | networking/udhcp/common.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c index a89dce3..cf6b1ca 100644 --- a/networking/udhcp/common.c +++ b/networking/udhcp/common.c @@ -29,9 +29,9 @@ 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 */ @@ -41,7 +41,7 @@ const struct dhcp_optflag dhcp_optflags[] = { //server would let us know anyway? { 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 */ @@ -49,7 +49,7 @@ 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 */ @@ -148,6 +148,7 @@ const uint8_t dhcp_option_lengths[] ALIGN1 = { [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, @@ -417,7 +418,9 @@ 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++; @@ -481,6 +484,7 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg) retval = udhcp_str2nip(val, buffer + 4); break; case OPTION_STRING: + case OPTION_STRING_HOST: #if ENABLE_FEATURE_UDHCP_RFC3397 case OPTION_DNS_STRING: #endif |