diff options
| -rw-r--r-- | tap.c | 15 | ||||
| -rw-r--r-- | tap.h | 51 |
2 files changed, 66 insertions, 0 deletions
@@ -386,6 +386,21 @@ void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n) pcap_multiple(iov, n, sizeof(uint32_t)); } +/** + * tap_update_mac() - Update tap L2 header with new Ethernet addresses + * @taph: Tap headers to update + * @eth_d: Ethernet destination address, NULL if unchanged + * @eth_s: Ethernet source address, NULL if unchanged + */ +void tap_update_mac(struct tap_hdr *taph, + const unsigned char *eth_d, const unsigned char *eth_s) +{ + if (eth_d) + memcpy(taph->eh.h_dest, eth_d, sizeof(taph->eh.h_dest)); + if (eth_s) + memcpy(taph->eh.h_source, eth_s, sizeof(taph->eh.h_source)); +} + PACKET_POOL_DECL(pool_l4, UIO_MAXIOV, pkt_buf); /** @@ -6,6 +6,55 @@ #ifndef TAP_H #define TAP_H +/** + * struct tap_hdr - L2 and tap specific headers + * @vnet_len: Frame length (for qemu socket transport) + * @eh: Ethernet header + */ +struct tap_hdr { + uint32_t vnet_len; + struct ethhdr eh; +} __attribute__((packed)); + +#define TAP_HDR_INIT(proto) { .eh.h_proto = htons_constant(proto) } + +static inline size_t tap_hdr_len_(const struct ctx *c) +{ + (void)c; + return sizeof(struct tap_hdr); +} + +/** + * tap_iov_base() - Find start of tap frame + * @c: Execution context + * @taph: Pointer to L2 header buffer + * + * Returns: pointer to the start of tap frame - suitable for an + * iov_base to be passed to tap_send_frames()) + */ +static inline void *tap_iov_base(const struct ctx *c, struct tap_hdr *taph) +{ + return (char *)(taph + 1) - tap_hdr_len_(c); +} + +/** + * tap_iov_len() - Finalize tap frame and return total length + * @c: Execution context + * @taph: Tap header to finalize + * @plen: L2 payload length (excludes L2 and tap specific headers) + * + * Returns: length of the tap frame including L2 and tap specific + * headers - suitable for an iov_len to be passed to + * tap_send_frames() + */ +static inline size_t tap_iov_len(const struct ctx *c, struct tap_hdr *taph, + size_t plen) +{ + if (c->mode == MODE_PASST) + taph->vnet_len = htonl(plen + sizeof(taph->eh)); + return plen + tap_hdr_len_(c); +} + struct in_addr tap_ip4_daddr(const struct ctx *c); void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport, struct in_addr dst, in_port_t dport, @@ -23,6 +72,8 @@ void tap_icmp6_send(const struct ctx *c, void *in, size_t len); int tap_send(const struct ctx *c, const void *data, size_t len); void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n); +void tap_update_mac(struct tap_hdr *taph, + const unsigned char *eth_d, const unsigned char *eth_s); void tap_handler(struct ctx *c, int fd, uint32_t events, const struct timespec *now); void tap_sock_init(struct ctx *c); |