diff options
Diffstat (limited to 'hw/net/pcnet.c')
| -rw-r--r-- | hw/net/pcnet.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 0eb3cc4d5b..1f4a3dbe49 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -1064,6 +1064,12 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) int pktcount = 0; if (!s->looptest) { + if (size > 4092) { +#ifdef PCNET_DEBUG_RMD + fprintf(stderr, "pcnet: truncates rx packet.\n"); +#endif + size = 4092; + } memcpy(src, buf, size); /* no need to compute the CRC */ src[size] = 0; @@ -1084,7 +1090,7 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) uint32_t fcs = ~0; uint8_t *p = src; - while (p != &src[size-4]) + while (p != &src[size]) CRC(fcs, *p++); crc_err = (*(uint32_t *)p != htonl(fcs)); } @@ -1233,8 +1239,10 @@ static void pcnet_transmit(PCNetState *s) bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT); /* if multi-tmd packet outsizes s->buffer then skip it silently. - Note: this is not what real hw does */ - if (s->xmit_pos + bcnt > sizeof(s->buffer)) { + * Note: this is not what real hw does. + * Last four bytes of s->buffer are used to store CRC FCS code. + */ + if (s->xmit_pos + bcnt > sizeof(s->buffer) - 4) { s->xmit_pos = -1; goto txdone; } |