diff options
Diffstat (limited to 'hw/net/smc91c111.c')
| -rw-r--r-- | hw/net/smc91c111.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/hw/net/smc91c111.c b/hw/net/smc91c111.c index 2295c6a..72ce5d8 100644 --- a/hw/net/smc91c111.c +++ b/hw/net/smc91c111.c @@ -22,6 +22,13 @@ /* Number of 2k memory pages available. */ #define NUM_PACKETS 4 +/* + * Maximum size of a data frame, including the leading status word + * and byte count fields and the trailing CRC, last data byte + * and control byte (per figure 8-1 in the Microchip Technology + * LAN91C111 datasheet). + */ +#define MAX_PACKET_SIZE 2048 #define TYPE_SMC91C111 "smc91c111" OBJECT_DECLARE_SIMPLE_TYPE(smc91c111_state, SMC91C111) @@ -240,6 +247,16 @@ static void smc91c111_release_packet(smc91c111_state *s, int packet) smc91c111_flush_queued_packets(s); } +static void smc91c111_complete_tx_packet(smc91c111_state *s, int packetnum) +{ + if (s->ctr & CTR_AUTO_RELEASE) { + /* Race? */ + smc91c111_release_packet(s, packetnum); + } else if (s->tx_fifo_done_len < NUM_PACKETS) { + s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum; + } +} + /* Flush the TX FIFO. */ static void smc91c111_do_tx(smc91c111_state *s) { @@ -263,6 +280,17 @@ static void smc91c111_do_tx(smc91c111_state *s) *(p++) = 0x40; len = *(p++); len |= ((int)*(p++)) << 8; + if (len > MAX_PACKET_SIZE) { + /* + * Datasheet doesn't say what to do here, and there is no + * relevant tx error condition listed. Log, and drop the packet. + */ + qemu_log_mask(LOG_GUEST_ERROR, + "smc91c111: tx packet with bad length %d, dropping\n", + len); + smc91c111_complete_tx_packet(s, packetnum); + continue; + } len -= 6; control = p[len + 1]; if (control & 0x20) @@ -291,11 +319,7 @@ static void smc91c111_do_tx(smc91c111_state *s) } } #endif - if (s->ctr & CTR_AUTO_RELEASE) - /* Race? */ - smc91c111_release_packet(s, packetnum); - else if (s->tx_fifo_done_len < NUM_PACKETS) - s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum; + smc91c111_complete_tx_packet(s, packetnum); qemu_send_packet(qemu_get_queue(s->nic), p, len); } s->tx_fifo_len = 0; |