diff options
Diffstat (limited to 'tap.c')
| -rw-r--r-- | tap.c | 84 |
1 files changed, 84 insertions, 0 deletions
@@ -53,6 +53,7 @@ #include "netlink.h" #include "pasta.h" #include "packet.h" +#include "tap.h" #include "log.h" /* IPv4 (plus ARP) and IPv6 message batches from tap/guest to IP handlers */ @@ -302,6 +303,89 @@ void tap_icmp6_send(const struct ctx *c, debug("tap: failed to send %lu bytes (IPv6)", len); } +/** + * tap_send_frames_pasta() - Send multiple frames to the pasta tap + * @c: Execution context + * @iov: Array of buffers, each containing one frame + * @n: Number of buffers/frames in @iov + * + * #syscalls:pasta write + */ +static void tap_send_frames_pasta(struct ctx *c, + const struct iovec *iov, size_t n) +{ + size_t i; + + for (i = 0; i < n; i++) { + if (write(c->fd_tap, (char *)iov->iov_base + 4, + iov->iov_len - 4) < 0) { + debug("tap write: %s", strerror(errno)); + if (errno != EAGAIN && errno != EWOULDBLOCK) + tap_handler(c, c->fd_tap, EPOLLERR, NULL); + i--; + } + } +} + +/** + * tap_send_frames_passt() - Send multiple frames to the passt tap + * @c: Execution context + * @iov: Array of buffers, each containing one frame + * @n: Number of buffers/frames in @iov + * + * #syscalls:passt sendmsg send + */ +static void tap_send_frames_passt(const struct ctx *c, + const struct iovec *iov, size_t n) +{ + struct msghdr mh = { + .msg_iov = (void *)iov, + .msg_iovlen = n, + }; + size_t end = 0, missing; + unsigned int i; + ssize_t sent; + char *p; + + sent = sendmsg(c->fd_tap, &mh, MSG_NOSIGNAL | MSG_DONTWAIT); + if (sent < 0) + return; + + /* Ensure a complete last message on partial sendmsg() */ + for (i = 0; i < n; i++, iov++) { + end += iov->iov_len; + if (end >= (size_t)sent) + break; + } + + missing = end - sent; + if (!missing) + return; + + p = (char *)iov->iov_base + iov->iov_len - missing; + if (send(c->fd_tap, p, missing, MSG_NOSIGNAL)) + debug("tap: failed to flush %lu missing bytes to tap", missing); +} + +/** + * tap_send_frames() - Send out multiple prepared frames + * @c: Execution context + * @iov: Array of buffers, each containing one frame (with L2 headers) + * @n: Number of buffers/frames in @iov + */ +void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n) +{ + if (!n) + return; + + if (c->mode == MODE_PASST) + tap_send_frames_passt(c, iov, n); + else + tap_send_frames_pasta(c, iov, n); + + pcap_multiple(iov, n, sizeof(uint32_t)); +} + PACKET_POOL_DECL(pool_l4, UIO_MAXIOV, pkt_buf); /** |