diff options
| -rw-r--r-- | hw/net/i82596.c | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/hw/net/i82596.c b/hw/net/i82596.c index ecdb9aa4f8..3b0efd0b57 100644 --- a/hw/net/i82596.c +++ b/hw/net/i82596.c @@ -497,7 +497,8 @@ ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz) uint32_t rfd_p; uint32_t rbd; uint16_t is_broadcast = 0; - size_t len = sz; + size_t len = sz; /* length of data for guest (including CRC) */ + size_t bufsz = sz; /* length of data in buf */ uint32_t crc; uint8_t *crc_ptr; uint8_t buf1[MIN_BUF_SIZE + VLAN_HLEN]; @@ -591,6 +592,7 @@ ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz) if (len < MIN_BUF_SIZE) { len = MIN_BUF_SIZE; } + bufsz = len; } /* Calculate the ethernet checksum (4 bytes) */ @@ -623,6 +625,7 @@ ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz) while (len) { uint16_t buffer_size, num; uint32_t rba; + size_t bufcount, crccount; /* printf("Receive: rbd is %08x\n", rbd); */ buffer_size = get_uint16(rbd + 12); @@ -635,14 +638,37 @@ ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz) } rba = get_uint32(rbd + 8); /* printf("rba is 0x%x\n", rba); */ - address_space_write(&address_space_memory, rba, - MEMTXATTRS_UNSPECIFIED, buf, num); - rba += num; - buf += num; - len -= num; - if (len == 0) { /* copy crc */ - address_space_write(&address_space_memory, rba - 4, - MEMTXATTRS_UNSPECIFIED, crc_ptr, 4); + /* + * Calculate how many bytes we want from buf[] and how many + * from the CRC. + */ + if ((len - num) >= 4) { + /* The whole guest buffer, we haven't hit the CRC yet */ + bufcount = num; + } else { + /* All that's left of buf[] */ + bufcount = len - 4; + } + crccount = num - bufcount; + + if (bufcount > 0) { + /* Still some of the actual data buffer to transfer */ + assert(bufsz >= bufcount); + bufsz -= bufcount; + address_space_write(&address_space_memory, rba, + MEMTXATTRS_UNSPECIFIED, buf, bufcount); + rba += bufcount; + buf += bufcount; + len -= bufcount; + } + + /* Write as much of the CRC as fits */ + if (crccount > 0) { + address_space_write(&address_space_memory, rba, + MEMTXATTRS_UNSPECIFIED, crc_ptr, crccount); + rba += crccount; + crc_ptr += crccount; + len -= crccount; } num |= 0x4000; /* set F BIT */ |