diff options
| -rw-r--r-- | source3/lib/interface.c | 88 |
1 files changed, 55 insertions, 33 deletions
diff --git a/source3/lib/interface.c b/source3/lib/interface.c index 95c0b9d53c..7ae97e9119 100644 --- a/source3/lib/interface.c +++ b/source3/lib/interface.c @@ -37,30 +37,32 @@ static struct interface *local_interfaces = NULL; struct interface *last_iface; +#define ALLONES ((uint32)0xFFFFFFFF) +#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES)) /**************************************************************************** calculate the default netmask for an address ****************************************************************************/ static void default_netmask(struct in_addr *inm, struct in_addr *iad) { - uint32 ad = ntohl(iad->s_addr); - uint32 nm; - /* - ** Guess a netmask based on the class of the IP address given. - */ - if ( (ad & 0x80000000) == 0 ) { - /* class A address */ - nm = 0xFF000000; - } else if ( (ad & 0xC0000000) == 0x80000000 ) { - /* class B address */ - nm = 0xFFFF0000; - } else if ( (ad & 0xE0000000) == 0xC0000000 ) { - /* class C address */ - nm = 0xFFFFFF00; - } else { - /* class D or E; netmask doesn't make much sense - guess 4 bits */ - nm = 0xFFFFFFF0; - } - inm->s_addr = htonl(nm); + /* + ** Guess a netmask based on the class of the IP address given. + */ + switch((ntohl(iad->s_addr) & 0xE0000000)) { + case 0: /* Class A addr */ + inm->s_addr = htonl(0xFF000000); + break; + + case 0x80000000: /* Class B addr */ + inm->s_addr = htonl(0xFFFF0000); + break; + + case 0xC0000000: /* Class C addr */ + inm->s_addr = htonl(0xFFFFFF00); + break; + + default: /* ??? */ + inm->s_addr = htonl(0xFFFFFFF0); + } } @@ -228,8 +230,30 @@ static void get_broadcast(struct in_addr *if_ipaddr, /* sanity check on the netmask */ { - uint32 nm = ntohl(if_nmask->s_addr); - if ((nm >> 24) != 0xFF) { + uint32 nm; + short onbc; + short offbc; + + nm = ntohl(if_nmask->s_addr); + onbc = 0; + offbc = 0; + while( (onbc + offbc) < 32 ) + { + if( nm & 0x80000000 ) + { + onbc++; + if( offbc ) /* already found an off bit, so mask is wrong */ + { + onbc = 34; + } + } + else + { + offbc++; + } + nm <<= 1; + } + if ((onbc < 8)||(onbc == 34)) { DEBUG(0,("Impossible netmask %s - using defaults\n",inet_ntoa(*if_nmask))); default_netmask(if_nmask, if_ipaddr); } @@ -239,10 +263,7 @@ static void get_broadcast(struct in_addr *if_ipaddr, all MS operating systems do, we have to comply even if the unix box is setup differently */ { - uint32 ad = ntohl(if_ipaddr->s_addr); - uint32 nm = ntohl(if_nmask->s_addr); - uint32 bc = (ad & nm) | (0xffffffff & ~nm); - if_bcast->s_addr = htonl(bc); + if_bcast->s_addr = MKBCADDR(if_ipaddr->s_addr, if_nmask->s_addr); } DEBUG(4,("Derived broadcast address %s\n", inet_ntoa(*if_bcast))); @@ -256,11 +277,12 @@ load a list of network interfaces static void interpret_interfaces(char *s, struct interface **interfaces, char *description) { - char *ptr = s; + char *ptr; fstring token; struct interface *iface; struct in_addr ip; + ptr = s; ipzero = *interpret_addr2("0.0.0.0"); allones_ip = *interpret_addr2("255.255.255.255"); loopback_ip = *interpret_addr2("127.0.0.1"); @@ -268,7 +290,7 @@ static void interpret_interfaces(char *s, struct interface **interfaces, while (next_token(&ptr,token,NULL)) { /* parse it into an IP address/netmasklength pair */ char *p = strchr(token,'/'); - if (p) *p = 0; + if (p) *p++ = 0; ip = *interpret_addr2(token); @@ -286,14 +308,14 @@ static void interpret_interfaces(char *s, struct interface **interfaces, iface->ip = ip; if (p) { - if (strlen(p+1)>2) - iface->nmask = *interpret_addr2(p+1); + if (strlen(p) > 2) + iface->nmask = *interpret_addr2(p); else - iface->nmask.s_addr = htonl(~((1<<(32-atoi(p+1)))-1)); + iface->nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES)); } else { default_netmask(&iface->nmask,&iface->ip); } - iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr; + iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr); iface->next = NULL; if (!(*interfaces)) { @@ -329,10 +351,10 @@ static void interpret_interfaces(char *s, struct interface **interfaces, if (got_nmask) { iface->nmask = default_nmask; - iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr; + iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr); } - if (iface->bcast.s_addr != (iface->ip.s_addr | ~iface->nmask.s_addr)) { + if (iface->bcast.s_addr != MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr)) { DEBUG(2,("Warning: inconsistant interface %s\n",inet_ntoa(iface->ip))); } |