diff options
| -rw-r--r-- | include/net/eth.h | 17 | ||||
| -rw-r--r-- | net/eth.c | 17 |
2 files changed, 34 insertions, 0 deletions
diff --git a/include/net/eth.h b/include/net/eth.h index 0671be6..7767ae8 100644 --- a/include/net/eth.h +++ b/include/net/eth.h @@ -31,6 +31,7 @@ #define ETH_ALEN 6 #define ETH_HLEN 14 +#define ETH_ZLEN 60 /* Min. octets in frame without FCS */ struct eth_header { uint8_t h_dest[ETH_ALEN]; /* destination eth addr */ @@ -422,4 +423,20 @@ bool eth_parse_ipv6_hdr(const struct iovec *pkt, int pkt_frags, size_t ip6hdr_off, eth_ip6_hdr_info *info); +/** + * eth_pad_short_frame - pad a short frame to the minimum Ethernet frame length + * + * If the Ethernet frame size is shorter than 60 bytes, it will be padded to + * 60 bytes at the address @padded_pkt. + * + * @padded_pkt: buffer address to hold the padded frame + * @padded_buflen: pointer holding length of @padded_pkt. If the frame is + * padded, the length will be updated to the padded one. + * @pkt: address to hold the original Ethernet frame + * @pkt_size: size of the original Ethernet frame + * @return true if the frame is padded, otherwise false + */ +bool eth_pad_short_frame(uint8_t *padded_pkt, size_t *padded_buflen, + const void *pkt, size_t pkt_size); + #endif @@ -548,3 +548,20 @@ bool eth_parse_ipv6_hdr(const struct iovec *pkt, int pkt_frags, info->l4proto = ext_hdr.ip6r_nxt; return true; } + +bool eth_pad_short_frame(uint8_t *padded_pkt, size_t *padded_buflen, + const void *pkt, size_t pkt_size) +{ + assert(padded_buflen && *padded_buflen >= ETH_ZLEN); + + if (pkt_size >= ETH_ZLEN) { + return false; + } + + /* pad to minimum Ethernet frame length */ + memcpy(padded_pkt, pkt, pkt_size); + memset(&padded_pkt[pkt_size], 0, ETH_ZLEN - pkt_size); + *padded_buflen = ETH_ZLEN; + + return true; +} |