From d036e6a149b7210c911521e14833dac76bbca035 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 18 Jul 2019 11:35:44 -0700 Subject: [PATCH] net: be more restrictive with ethernet address format The current ether_unformat_addr code was based off of BSD ether_aton. That version changed what was allowed by the cmdline ether address parser. For example, it allows dropping leading zeros. Change the code to be more restrictive and only allow the fully expanded standard formats. Bugzilla ID: 324 Fixes: 596d31092d32 ("net: add function to convert string to ethernet address") Signed-off-by: Stephen Hemminger Reviewed-by: Olivier Matz --- lib/librte_net/rte_ether.c | 113 ++++++++++++++++++++++++------------- lib/librte_net/rte_ether.h | 3 + 2 files changed, 78 insertions(+), 38 deletions(-) diff --git a/lib/librte_net/rte_ether.c b/lib/librte_net/rte_ether.c index 8d040173cf..ced65ed9f3 100644 --- a/lib/librte_net/rte_ether.c +++ b/lib/librte_net/rte_ether.c @@ -2,6 +2,8 @@ * Copyright(c) 2010-2014 Intel Corporation */ +#include + #include #include @@ -29,50 +31,85 @@ rte_ether_format_addr(char *buf, uint16_t size, eth_addr->addr_bytes[5]); } +static int8_t get_xdigit(char ch) +{ + if (ch >= '0' && ch <= '9') + return ch - '0'; + if (ch >= 'a' && ch <= 'f') + return ch - 'a' + 10; + if (ch >= 'A' && ch <= 'F') + return ch - 'A' + 10; + return -1; +} + +/* Convert 00:11:22:33:44:55 to ethernet address */ +static bool get_ether_addr6(const char *s0, struct rte_ether_addr *ea) +{ + const char *s = s0; + int i; + + for (i = 0; i < RTE_ETHER_ADDR_LEN; i++) { + int8_t x; + + x = get_xdigit(*s++); + if (x < 0) + return false; + + ea->addr_bytes[i] = x << 4; + x = get_xdigit(*s++); + if (x < 0) + return false; + ea->addr_bytes[i] |= x; + + if (i < RTE_ETHER_ADDR_LEN - 1 && + *s++ != ':') + return false; + } + + /* return true if at end of string */ + return *s == '\0'; +} + +/* Convert 0011:2233:4455 to ethernet address */ +static bool get_ether_addr3(const char *s, struct rte_ether_addr *ea) +{ + int i, j; + + for (i = 0; i < RTE_ETHER_ADDR_LEN; i += 2) { + uint16_t w = 0; + + for (j = 0; j < 4; j++) { + int8_t x; + + x = get_xdigit(*s++); + if (x < 0) + return false; + w = (w << 4) | x; + } + ea->addr_bytes[i] = w >> 8; + ea->addr_bytes[i + 1] = w & 0xff; + + if (i < RTE_ETHER_ADDR_LEN - 2 && + *s++ != ':') + return false; + } + + return *s == '\0'; +} + /* * Like ether_aton_r but can handle either * XX:XX:XX:XX:XX:XX or XXXX:XXXX:XXXX + * and is more restrictive. */ int rte_ether_unformat_addr(const char *s, struct rte_ether_addr *ea) { - unsigned int o0, o1, o2, o3, o4, o5; - int n; - - n = sscanf(s, "%x:%x:%x:%x:%x:%x", - &o0, &o1, &o2, &o3, &o4, &o5); - - if (n == 6) { - /* Standard format XX:XX:XX:XX:XX:XX */ - if (o0 > UINT8_MAX || o1 > UINT8_MAX || o2 > UINT8_MAX || - o3 > UINT8_MAX || o4 > UINT8_MAX || o5 > UINT8_MAX) { - rte_errno = ERANGE; - return -1; - } + if (get_ether_addr6(s, ea)) + return 0; + if (get_ether_addr3(s, ea)) + return 0; - ea->addr_bytes[0] = o0; - ea->addr_bytes[1] = o1; - ea->addr_bytes[2] = o2; - ea->addr_bytes[3] = o3; - ea->addr_bytes[4] = o4; - ea->addr_bytes[5] = o5; - } else if (n == 3) { - /* Support the format XXXX:XXXX:XXXX */ - if (o0 > UINT16_MAX || o1 > UINT16_MAX || o2 > UINT16_MAX) { - rte_errno = ERANGE; - return -1; - } - - ea->addr_bytes[0] = o0 >> 8; - ea->addr_bytes[1] = o0 & 0xff; - ea->addr_bytes[2] = o1 >> 8; - ea->addr_bytes[3] = o1 & 0xff; - ea->addr_bytes[4] = o2 >> 8; - ea->addr_bytes[5] = o2 & 0xff; - } else { - /* unknown format */ - rte_errno = EINVAL; - return -1; - } - return 0; + rte_errno = EINVAL; + return -1; } diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h index 8a040abf56..aa6eff037f 100644 --- a/lib/librte_net/rte_ether.h +++ b/lib/librte_net/rte_ether.h @@ -252,6 +252,9 @@ rte_ether_format_addr(char *buf, uint16_t size, * * @param str * A pointer to buffer contains the formatted MAC address. + * The supported formats are: + * XX:XX:XX:XX:XX:XX or XXXX:XXXX:XXXX + * where XX is a hex digit: 0-9, a-f, or A-F. * @param eth_addr * A pointer to a ether_addr structure. * @return -- 2.20.1