diff options
Diffstat (limited to 'pfinet/linux-inet/devinet.c')
| -rw-r--r-- | pfinet/linux-inet/devinet.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/pfinet/linux-inet/devinet.c b/pfinet/linux-inet/devinet.c new file mode 100644 index 00000000..946536be --- /dev/null +++ b/pfinet/linux-inet/devinet.c @@ -0,0 +1,213 @@ +/* + * NET3 IP device support routines. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Derived from the IP parts of dev.c 1.0.19 + * Authors: Ross Biro, <bir7@leland.Stanford.Edu> + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * + * Additional Authors: + * Alan Cox, <gw4pts@gw4pts.ampr.org> + */ + +#include <asm/segment.h> +#include <asm/system.h> +#include <asm/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/if_ether.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include "ip.h" +#include "route.h" +#include "protocol.h" +#include "tcp.h" +#include <linux/skbuff.h> +#include "sock.h" +#include "arp.h" + +/* + * Determine a default network mask, based on the IP address. + */ + +unsigned long ip_get_mask(unsigned long addr) +{ + unsigned long dst; + + if (addr == 0L) + return(0L); /* special case */ + + dst = ntohl(addr); + if (IN_CLASSA(dst)) + return(htonl(IN_CLASSA_NET)); + if (IN_CLASSB(dst)) + return(htonl(IN_CLASSB_NET)); + if (IN_CLASSC(dst)) + return(htonl(IN_CLASSC_NET)); + + /* + * Something else, probably a multicast. + */ + + return(0); +} + +/* + * Check the address for our address, broadcasts, etc. + * + * I intend to fix this to at the very least cache the last + * resolved entry. + */ + +int ip_chk_addr(unsigned long addr) +{ + struct device *dev; + unsigned long mask; + + /* + * Accept both `all ones' and `all zeros' as BROADCAST. + * (Support old BSD in other words). This old BSD + * support will go very soon as it messes other things + * up. + * Also accept `loopback broadcast' as BROADCAST. + */ + + if (addr == INADDR_ANY || addr == INADDR_BROADCAST || + addr == htonl(0x7FFFFFFFL)) + return IS_BROADCAST; + + mask = ip_get_mask(addr); + + /* + * Accept all of the `loopback' class A net. + */ + + if ((addr & mask) == htonl(0x7F000000L)) + return IS_MYADDR; + + /* + * OK, now check the interface addresses. + */ + + for (dev = dev_base; dev != NULL; dev = dev->next) + { + if (!(dev->flags & IFF_UP)) + continue; + /* + * If the protocol address of the device is 0 this is special + * and means we are address hunting (eg bootp). + */ + + if ((dev->pa_addr == 0)/* || (dev->flags&IFF_PROMISC)*/) + return IS_MYADDR; + /* + * Is it the exact IP address? + */ + + if (addr == dev->pa_addr) + return IS_MYADDR; + /* + * Is it our broadcast address? + */ + + if ((dev->flags & IFF_BROADCAST) && addr == dev->pa_brdaddr) + return IS_BROADCAST; + /* + * Nope. Check for a subnetwork broadcast. + */ + + if (((addr ^ dev->pa_addr) & dev->pa_mask) == 0) + { + if ((addr & ~dev->pa_mask) == 0) + return IS_BROADCAST; + if ((addr & ~dev->pa_mask) == ~dev->pa_mask) + return IS_BROADCAST; + } + + /* + * Nope. Check for Network broadcast. + */ + + if (((addr ^ dev->pa_addr) & mask) == 0) + { + if ((addr & ~mask) == 0) + return IS_BROADCAST; + if ((addr & ~mask) == ~mask) + return IS_BROADCAST; + } + } + if(IN_MULTICAST(ntohl(addr))) + return IS_MULTICAST; + return 0; /* no match at all */ +} + + +/* + * Retrieve our own address. + * + * Because the loopback address (127.0.0.1) is already recognized + * automatically, we can use the loopback interface's address as + * our "primary" interface. This is the address used by IP et + * al when it doesn't know which address to use (i.e. it does not + * yet know from or to which interface to go...). + */ + +unsigned long ip_my_addr(void) +{ + struct device *dev; + + for (dev = dev_base; dev != NULL; dev = dev->next) + { + if (dev->flags & IFF_LOOPBACK) + return(dev->pa_addr); + } + return(0); +} + +/* + * Find an interface that can handle addresses for a certain address. + * + * This needs optimising, since it's relatively trivial to collapse + * the two loops into one. + */ + +struct device * ip_dev_check(unsigned long addr) +{ + struct device *dev; + + for (dev = dev_base; dev; dev = dev->next) + { + if (!(dev->flags & IFF_UP)) + continue; + if (!(dev->flags & IFF_POINTOPOINT)) + continue; + if (addr != dev->pa_dstaddr) + continue; + return dev; + } + for (dev = dev_base; dev; dev = dev->next) + { + if (!(dev->flags & IFF_UP)) + continue; + if (dev->flags & IFF_POINTOPOINT) + continue; + if (dev->pa_mask & (addr ^ dev->pa_addr)) + continue; + return dev; + } + return NULL; +} |