diff --git a/hw/eepro100.c b/hw/eepro100.c index 848bf79461..ab5c699c9d 100644 --- a/hw/eepro100.c +++ b/hw/eepro100.c @@ -48,6 +48,15 @@ #include "eeprom93xx.h" #include "sysemu.h" +/* QEMU sends frames smaller than 60 bytes to ethernet nics. + * Such frames are rejected by real nics and their emulations. + * To avoid this behaviour, other nic emulations pad received + * frames. The following definition enables this padding for + * eepro100, too. We keep the define around in case it might + * become useful the future if the core networking is ever + * changed to pad short packets itself. */ +#define CONFIG_PAD_RECEIVED_FRAMES + #define KiB 1024 /* Debug EEPRO100 card. */ @@ -1640,19 +1649,32 @@ static ssize_t nic_receive(VLANClientState *nc, const uint8_t * buf, size_t size */ EEPRO100State *s = DO_UPCAST(NICState, nc, nc)->opaque; uint16_t rfd_status = 0xa000; +#if defined(CONFIG_PAD_RECEIVED_FRAMES) + uint8_t min_buf[60]; +#endif static const uint8_t broadcast_macaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; +#if defined(CONFIG_PAD_RECEIVED_FRAMES) + /* Pad to minimum Ethernet frame length */ + if (size < sizeof(min_buf)) { + memcpy(min_buf, buf, size); + memset(&min_buf[size], 0, sizeof(min_buf) - size); + buf = min_buf; + size = sizeof(min_buf); + } +#endif + if (s->configuration[8] & 0x80) { /* CSMA is disabled. */ logout("%p received while CSMA is disabled\n", s); return -1; +#if !defined(CONFIG_PAD_RECEIVED_FRAMES) } else if (size < 64 && (s->configuration[7] & BIT(0))) { /* Short frame and configuration byte 7/0 (discard short receive) set: * Short frame is discarded */ logout("%p received short frame (%zu byte)\n", s, size); s->statistics.rx_short_frame_errors++; -#if 0 return -1; #endif } else if ((size > MAX_ETH_FRAME_SIZE + 4) && !(s->configuration[18] & BIT(3))) { @@ -1731,9 +1753,11 @@ static ssize_t nic_receive(VLANClientState *nc, const uint8_t * buf, size_t size "(%zu bytes); data truncated\n", rfd_size, size); size = rfd_size; } +#if !defined(CONFIG_PAD_RECEIVED_FRAMES) if (size < 64) { rfd_status |= 0x0080; } +#endif TRACE(OTHER, logout("command 0x%04x, link 0x%08x, addr 0x%08x, size %u\n", rfd_command, rx.link, rx.rx_buf_addr, rfd_size)); stw_phys(s->ru_base + s->ru_offset + offsetof(eepro100_rx_t, status),