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charset="utf-8" Add the AF_PACKET capture read path for socket chardevs. When opened with af-packet-mode=3Dcapture, the read side drains raw frames with recvfrom(), keeps only PACKET_OUTGOING traffic, and feeds the result through the normal chardev frontend interface. Signed-off-by: Cindy Lu --- chardev/char-socket.c | 133 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 131 insertions(+), 2 deletions(-) diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 45d06fda8f..76a51a853d 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -107,9 +107,17 @@ static void tcp_chr_accept(QIONetListener *listener, =20 static int tcp_chr_read_poll(void *opaque); static void tcp_chr_disconnect_locked(Chardev *chr); +static void tcp_chr_deliver_af_packet(Chardev *chr); =20 #define TCP_CHARDEV_AF_PACKET_MAX_FRAME_SIZE 65536 =20 +static bool +tcp_chr_uses_af_packet_capture(SocketChardev *s) +{ + return s->is_af_packet && s->af_packet_mode_set && + s->af_packet_mode =3D=3D CHARDEV_SOCKET_AF_PACKET_MODE_CAPTURE; +} + static bool tcp_chr_uses_af_packet_inject(SocketChardev *s) { return s->is_af_packet && @@ -300,6 +308,9 @@ static int tcp_chr_read_poll(void *opaque) return 0; } s->max_size =3D qemu_chr_be_can_write(chr); + if (tcp_chr_uses_af_packet_capture(s) && s->af_packet_buf_len) { + tcp_chr_deliver_af_packet(chr); + } return s->max_size; } =20 @@ -500,6 +511,98 @@ static void tcp_chr_reset_af_packet_send(SocketChardev= *s) s->af_packet_send_len_bytes =3D 0; } =20 +/* Push buffered AF_PACKET capture data into the chardev frontend. */ +static void +tcp_chr_deliver_af_packet(Chardev *chr) +{ + SocketChardev *s =3D SOCKET_CHARDEV(chr); + + while (s->max_size > 0 && s->af_packet_buf_offset < s->af_packet_buf_l= en) { + size_t remaining =3D s->af_packet_buf_len - s->af_packet_buf_offse= t; + size_t chunk =3D MIN((size_t)s->max_size, remaining); + + qemu_chr_be_write(chr, s->af_packet_buf + s->af_packet_buf_offset, + (int)chunk); + s->af_packet_buf_offset +=3D chunk; + s->max_size =3D qemu_chr_be_can_write(chr); + } + + if (s->af_packet_buf_offset =3D=3D s->af_packet_buf_len) { + tcp_chr_reset_af_packet_buf(s); + } +} + +/* Copy buffered AF_PACKET capture data into a synchronous read buffer. */ +static int tcp_chr_copy_af_packet_buf(SocketChardev *s, uint8_t *buf, + int len) { + size_t remaining =3D s->af_packet_buf_len - s->af_packet_buf_offset; + size_t copied =3D MIN((size_t)len, remaining); + + memcpy(buf, s->af_packet_buf + s->af_packet_buf_offset, copied); + s->af_packet_buf_offset +=3D copied; + + if (s->af_packet_buf_offset =3D=3D s->af_packet_buf_len) { + tcp_chr_reset_af_packet_buf(s); + } + + return (int)copied; +} + +static ssize_t +tcp_chr_capture_af_packet(Chardev *chr) +{ +#ifdef CONFIG_LINUX + SocketChardev *s =3D SOCKET_CHARDEV(chr); + struct sockaddr_ll sll; + socklen_t sll_len; + ssize_t size; + uint32_t len; + + if (!tcp_chr_uses_af_packet_capture(s)) { + errno =3D EIO; + return -1; + } + + if (s->af_packet_buf_size < + sizeof(len) + TCP_CHARDEV_AF_PACKET_MAX_FRAME_SIZE) { + s->af_packet_buf =3D + g_realloc(s->af_packet_buf, + sizeof(len) + TCP_CHARDEV_AF_PACKET_MAX_FRAME_SIZE); + s->af_packet_buf_size =3D + sizeof(len) + TCP_CHARDEV_AF_PACKET_MAX_FRAME_SIZE; + } + + for (;;) { + sll_len =3D sizeof(sll); + do { + size =3D recvfrom(s->sioc->fd, s->af_packet_buf + sizeof(len), + TCP_CHARDEV_AF_PACKET_MAX_FRAME_SIZE, 0, + (struct sockaddr *)&sll, &sll_len); + } while (size < 0 && errno =3D=3D EINTR); + + if (size <=3D 0) { + if (size < 0 && errno !=3D EAGAIN && errno !=3D EWOULDBLOCK) { + trace_chr_socket_recv_err(chr, chr->label, g_strerror(errn= o)); + } + return size; + } + + if (sll.sll_pkttype !=3D PACKET_OUTGOING) { + continue; + } + + len =3D htonl(size); + memcpy(s->af_packet_buf, &len, sizeof(len)); + s->af_packet_buf_len =3D sizeof(len) + size; + s->af_packet_buf_offset =3D 0; + return (ssize_t)s->af_packet_buf_len; + } +#else + errno =3D EPROTONOSUPPORT; + return -1; +#endif +} + static GSource *tcp_chr_add_watch(Chardev *chr, GIOCondition cond) { SocketChardev *s =3D SOCKET_CHARDEV(chr); @@ -682,6 +785,22 @@ static gboolean tcp_chr_read(QIOChannel *chan, GIOCond= ition cond, void *opaque) if (len > s->max_size) { len =3D s->max_size; } + if (tcp_chr_uses_af_packet_capture(s)) { + tcp_chr_deliver_af_packet(chr); + if (s->max_size <=3D 0 || s->af_packet_buf_len) { + return TRUE; + } + + size =3D tcp_chr_capture_af_packet(chr); + if (size =3D=3D 0 || (size =3D=3D -1 && errno !=3D EAGAIN)) { + tcp_chr_disconnect(chr); + } else if (size > 0) { + tcp_chr_deliver_af_packet(chr); + } + + return TRUE; + } + size =3D tcp_chr_recv(chr, (void *)buf, len); if (size =3D=3D 0 || (size =3D=3D -1 && errno !=3D EAGAIN)) { /* connection closed */ @@ -715,6 +834,10 @@ static int tcp_chr_sync_read(Chardev *chr, const uint8= _t *buf, int len) int saved_errno; Error *local_err =3D NULL; =20 + if (tcp_chr_uses_af_packet_capture(s) && s->af_packet_buf_len) { + return tcp_chr_copy_af_packet_buf(s, (uint8_t *)buf, len); + } + if (s->state !=3D TCP_CHARDEV_STATE_CONNECTED) { return 0; } @@ -723,7 +846,14 @@ static int tcp_chr_sync_read(Chardev *chr, const uint8= _t *buf, int len) error_report_err(local_err); return -1; } - size =3D tcp_chr_recv(chr, (void *) buf, len); + if (tcp_chr_uses_af_packet_capture(s)) { + size =3D tcp_chr_capture_af_packet(chr); + if (size > 0) { + size =3D tcp_chr_copy_af_packet_buf(s, (uint8_t *)buf, len); + } + } else { + size =3D tcp_chr_recv(chr, (void *)buf, len); + } saved_errno =3D errno; if (s->state !=3D TCP_CHARDEV_STATE_DISCONNECTED) { if (!qio_channel_set_blocking(s->ioc, false, &local_err)) { @@ -1448,7 +1578,6 @@ static gboolean socket_reconnect_timeout(gpointer opa= que) return false; } =20 - static int qmp_chardev_open_socket_server(Chardev *chr, bool is_telnet, bool is_waitconnect, --=20 2.52.0