diff options
| -rw-r--r-- | src/dev/net/ethertap.cc | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/src/dev/net/ethertap.cc b/src/dev/net/ethertap.cc index 8d08cc2d2..4e32a8c46 100644 --- a/src/dev/net/ethertap.cc +++ b/src/dev/net/ethertap.cc @@ -406,7 +406,7 @@ EtherTapStub::sendReal(const void *data, size_t len) EtherTap::EtherTap(const Params *p) : EtherTapBase(p) { - int fd = open(p->tun_clone_device.c_str(), O_RDWR); + int fd = open(p->tun_clone_device.c_str(), O_RDWR | O_NONBLOCK); if (fd < 0) panic("Couldn't open %s.\n", p->tun_clone_device); @@ -438,18 +438,39 @@ EtherTap::recvReal(int revent) if (!(revent & POLLIN)) return; - ssize_t ret = read(tap, buffer, buflen); - if (ret < 0) - panic("Failed to read from tap device.\n"); + ssize_t ret; + while ((ret = read(tap, buffer, buflen))) { + if (ret < 0) { + if (errno == EAGAIN) + break; + panic("Failed to read from tap device.\n"); + } - sendSimulated(buffer, ret); + sendSimulated(buffer, ret); + } } bool EtherTap::sendReal(const void *data, size_t len) { - if (write(tap, data, len) != len) - panic("Failed to write data to tap device.\n"); + int n; + pollfd pfd[1]; + pfd->fd = tap; + pfd->events = POLLOUT; + + // `tap` is a nonblock fd. Here we try to write until success, and use + // poll to make a blocking wait. + while ((n = write(tap, data, len)) != len) { + if (errno != EAGAIN) + panic("Failed to write data to tap device.\n"); + pfd->revents = 0; + int ret = poll(pfd, 1, -1); + // timeout is set to inf, we shouldn't get 0 in any case. + assert(ret != 0); + if (ret == -1 || (ret == 1 && (pfd->revents & POLLERR))) { + panic("Failed when polling to write data to tap device.\n"); + } + } return true; } |