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Ethernet Layer
[Networking]

Data Structures
struct	ethernet
	An ethernet packet structure. More...
Typedefs
typedef ethernet	ethernet_t
	An ethernet packet structure.
Functions
void	to_eth_layer (ethernet_t *packet, size_t len)
	Process an ethernet packet received from the physical layer. Parameters: packet  The ethernet packet received. len  The size of the packet.
int	send_eth_packet (const uint8_t *to, const void *data, size_t len, uint16_t type)
	Send an ethernet packet to the physiscal layer. Parameters: to  The destination ethernet address (MAC). data  The buffer of data to be sent. len  The size of the buffer of data to be sent. type  The packet type. Returns: The number of bytes sent in case of success. -ENOMEM cannot allocate the packet structure. -ENXIO no ethernet device found.
bool	is_eth_promisc ()
	Check if the ethernet device has been configured in promiscuous mode. Returns: TRUE the ethernet card is in promiscuous mode; FALSE the ethernet card is not in promiscuous mode.
void	ifconfig (char *cmd)
	This is the "ifconfig" command for the shell. Parameters: cmd  A string of command parameters.

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Detailed Description

The ethernet layer.

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Typedef Documentation

typedef struct ethernet ethernet_t

An ethernet packet structure.

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Function Documentation

void ifconfig (  char *    cmd )

This is the "ifconfig" command for the shell. Parameters: cmd  A string of command parameters. Definition at line 273 of file eth.c. { uint8_t ip_dot[STR_MAX_LENGTH]; in_addr_t ip, netmask; // Skip initial spaces into the parameters string // while (*cmd == ' ') cmd++; if (*cmd == '\0') { // Simply print current ethernet configuration // rtl8139_dump_info(rtl); return; } if ( strstr(cmd, "up") ) { if ( rtl != NULL ) { kprintf("\n\rRTL8139 is already up!"); if ( strstr(cmd, "promisc") ) rtl8139_promisc(get_rtl8139_device(), TRUE); else rtl8139_promisc(get_rtl8139_device(), FALSE); kprintf("\n\rRTL8139: promiscuous mode %s\n\r", (get_rtl8139_device()->promisc) ? "ENABLED" : "DISABLED"); return; } // Get the host IP and netmask // kprintf("\n\rIP address: "); gets(ip_dot); if ( !inet_aton(ip_dot, &ip) ) { // Set the IP to default value // ip = DEFAULT_IP_ADDR; } kprintf("\rNetmask : "); gets(ip_dot); if ( !inet_aton(ip_dot, &netmask) ) { // Set the netmask to default value // netmask = DEFAULT_NETMASK_ADDR; } // Set the host ip and netmask addresses // set_host_ip_net(ip, netmask); // Initialize the ethernet buffer // eth_init_buffer(); // Reset the ARP cache // arp_reset_cache(); // Open the TCP module // tcp_module_init(); // Initialize the RTL8139 device // switch( rtl8139_init(strstr(cmd, "promisc") ? TRUE : FALSE) ) { case ( 0 ): // --- SUCCESS --- // // Dump the ethernet card informations // rtl8139_dump_info(rtl); // Create the ethernet receiver thread // eth_recv_thread1 = create_process( &eth_recv_daemon, &eth_recv_daemon, 0, "eth_recvd1", KERNEL_PRIVILEGE); eth_recv_thread2 = create_process( &eth_recv_daemon, &eth_recv_daemon, 0, "eth_recvd2", KERNEL_PRIVILEGE); break; case ( -ENXIO ): // --- DEVICE NOT FOUND --- // // Null the host ip and netmask // set_host_ip_net(0, 0); // Destroy the ethernet buffer // kfree( eth_recv_buf ); // Print the error message // kprintf("\n\rRTL8139: cannot find an ethernet card!\n\r"); break; case ( -EIO ): // --- I/O ERROR --- // // Null the host ip and netmask // set_host_ip_net(0, 0); // Destroy the ethernet buffer // kfree( eth_recv_buf ); // Print the error message // kprintf("\n\rRTL8139: I/O error!\n\r"); break; } return; } if ( strstr(cmd, "down") ) { kprintf("\n\rRTL8139: shutting down eth0 device..."); // Close the TCP module // tcp_module_close(); // Destroy the ethernet buffer // kfree( eth_recv_buf ); // Kill the ethernet receiver thread // kill(eth_recv_thread1->pid); kill(eth_recv_thread2->pid); // Reset the ARP cache // arp_reset_cache(); // Close the RTL8139 interface // rtl8139_close(&rtl); kprintf("\n\r"); return; } // Command unknown! // kprintf("\n\rerror: %s unknown!\n\r", cmd); }

bool is_eth_promisc (    )

Check if the ethernet device has been configured in promiscuous mode. Returns: TRUE the ethernet card is in promiscuous mode; FALSE the ethernet card is not in promiscuous mode. Definition at line 261 of file eth.c. { return( get_rtl8139_device()->promisc ); }

int send_eth_packet (  const uint8_t *    to, const void *    data, size_t    len, uint16_t    type )

Send an ethernet packet to the physiscal layer. Parameters: to  The destination ethernet address (MAC). data  The buffer of data to be sent. len  The size of the buffer of data to be sent. type  The packet type. Returns: The number of bytes sent in case of success. -ENOMEM cannot allocate the packet structure. -ENXIO no ethernet device found. Definition at line 206 of file eth.c. { uint8_t *packet; uint8_t *mac_addr; // Analyze the packet length (must be less than ETH_MTU) // // TODO: if the packet length if great than ETH_MTU // // perform a packet fragmentation. // len = MIN(len, ETH_MTU); // Create the ethernet packet // packet = kmalloc( MAX(len+ETH_HEAD_LEN, ETH_MIN_LEN) ); if (!packet) return(-ENOMEM); // Get the local mac address // if ( (mac_addr = get_eth_mac_addr()) == NULL ) // No such device or address! // return(-ENXIO); // Add the ethernet header to the packet // memcpy(packet, to, ETH_ADDR_LEN); memcpy(packet + ETH_ADDR_LEN, mac_addr, ETH_ADDR_LEN); memcpy(packet + 2 * ETH_ADDR_LEN, &type, sizeof(uint16_t)); // Copy the data into the packet // memcpy(packet + ETH_HEAD_LEN, data, len); // Adjust the packet length including the size of the header // len += ETH_HEAD_LEN; // Auto-pad! Send a minimum payload (another 4 bytes are // // sent automatically for the FCS, totalling to 64 bytes) // // It is the minimum length of an ethernet packet. // while (len < ETH_MIN_LEN) packet[len++] = '\0'; // Go to the physical layer // len = send_rtl8139_packet(get_rtl8139_device(), packet, len); // Free the memory of the packet // kfree(packet); // Return the bytes transmitted at this level // return(len); }

void to_eth_layer (  ethernet_t *    packet, size_t    len )

Process an ethernet packet received from the physical layer. Parameters: packet  The ethernet packet received. len  The size of the packet. Definition at line 153 of file eth.c. { DOWN(&eth_recv_buf->mutex); #ifdef ETH_DEBUG // Strip the ethernet header // kprintf("\n\rMAC DEST = %02x:%02x:%02x:%02x:%02x:%02x", packet->dst[0], packet->dst[1], packet->dst[2], packet->dst[3], packet->dst[4], packet->dst[5]); kprintf("\n\rMAC SOURCE = %02x:%02x:%02x:%02x:%02x:%02x", packet->src[0], packet->src[1], packet->src[2], packet->src[3], packet->src[4], packet->src[5]); kprintf("\n\rPACK TYPE = %04x", ntohs(packet->type)); kprintf("\n\rTOT LENGTH = %u bytes", len); #endif // Store the packet data into the send buffer // memcpy( eth_recv_buf->packet[eth_recv_buf->write].data, packet, len = MIN(len, ETH_FRAME_LEN) ); // Store the packet length // eth_recv_buf->packet[eth_recv_buf->write].length = len; // Update the recv buffer write pointer // eth_recv_buf->write = (eth_recv_buf->write + 1) % ETH_RECV_BUF_DIM; if (eth_recv_buf->count <= ETH_RECV_BUF_DIM) // Update the packet counter // (eth_recv_buf->count)++; else // The oldest packet has been overwritten, so update // // also the read pointer // eth_recv_buf->read = (eth_recv_buf->read + 1) % ETH_RECV_BUF_DIM; UP(&eth_recv_buf->mutex); // Wakeup the receive daemons // wakeup_task( eth_recv_thread1 ); wakeup_task( eth_recv_thread2 ); }

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