add getifaddrs(3) from bsdi. this is a magic function which lets you grab

interface addresses in a portable manner, without headache of SIOCGIFCONF
or sysctl.  it is in bsdi/openbsd/netbsd already.
from kame tree (actually, mandatory for latest kame tree).

3 files changed, 545 insertions, 2 deletions

diff --git a/lib/libc/net/Makefile.inc b/lib/libc/net/Makefile.inc
index 22c4010..1d3ab66 100644
--- a/lib/libc/net/Makefile.inc
+++ b/lib/libc/net/Makefile.inc
@@ -6,7 +6,7 @@
 
 SRCS+=	addr2ascii.c ascii2addr.c base64.c ether_addr.c getaddrinfo.c \
 	gethostbydns.c gethostbyht.c gethostbynis.c gethostnamadr.c \
-	getnameinfo.c \
+	getifaddrs.c getnameinfo.c \
 	getnetbydns.c getnetbyht.c getnetbynis.c getnetnamadr.c \
 	getproto.c getprotoent.c getprotoname.c getservbyname.c \
 	getservbyport.c getservent.c herror.c inet_addr.c ifname.c \
@@ -28,7 +28,7 @@ CFLAGS+=-DINET6
 
 .if ${LIB} == "c"
 MAN3+=	addr2ascii.3 byteorder.3 ethers.3 getaddrinfo.3 gethostbyname.3 \
-	getipnodebyname.3 \
+	getifaddrs.3 getipnodebyname.3 \
 	getnameinfo.3 getnetent.3 getprotoent.3 getservent.3 if_indextoname.3 \
 	inet.3 inet6_option_space.3 inet6_rthdr_space.3 linkaddr.3 \
 	rcmd.3 resolver.3
@@ -44,6 +44,7 @@ MLINKS+=gethostbyname.3 endhostent.3 gethostbyname.3 gethostbyaddr.3 \
 	gethostbyname.3 gethostbyname2.3 gethostbyname.3 gethostent.3 \
 	gethostbyname.3 herror.3 gethostbyname.3 hstrerror.3 \
 	gethostbyname.3 sethostent.3
+MLINKS+=getifaddrs.3 freeifaddrs.3
 MLINKS+=getipnodebyname.3 getipnodebyaddr.3 getipnodebyname.3 freehostent.3
 MLINKS+=getnetent.3 endnetent.3 getnetent.3 getnetbyaddr.3 \
 	getnetent.3 getnetbyname.3 getnetent.3 setnetent.3
diff --git a/lib/libc/net/getifaddrs.3 b/lib/libc/net/getifaddrs.3
new file mode 100644
index 0000000..f2fa749
--- /dev/null
+++ b/lib/libc/net/getifaddrs.3
@@ -0,0 +1,163 @@
+.\"	$FreeBSD$
+.\"	$KAME: getifaddrs.3,v 1.4 2000/05/17 14:13:14 itojun Exp $
+.\"	BSDI	getifaddrs.3,v 2.5 2000/02/23 14:51:59 dab Exp
+.\"
+.\" Copyright (c) 1995, 1999
+.\"	Berkeley Software Design, Inc.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.Dd "October 12, 1995"
+.Dt GETIFADDRS 3
+.Sh NAME
+.Nm getifaddrs
+.Nd get interface addresses
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <sys/socket.h>
+.Fd #include <ifaddrs.h>
+.Ft int
+.Fn getifaddrs "struct ifaddrs **ifap"
+.Ft void
+.Fn freeifaddrs "struct ifaddrs *ifp"
+.Sh DESCRIPTION
+The
+.Fn getifaddrs
+function stores a reference to a linked list of the network interfaces
+on the local machine in the memory referenced by
+.Fa ifap .
+The list consists of
+.Nm ifaddrs
+structures, as defined in the include file
+.Aq Pa ifaddrs.h .
+The
+.Nm ifaddrs
+structure contains at least the following entries:
+.Bd -literal
+    struct ifaddrs   *ifa_next;         /* Pointer to next struct */
+    char             *ifa_name;         /* Interface name */
+    u_int             ifa_flags;        /* Interface flags */
+    struct sockaddr  *ifa_addr;         /* Interface address */
+    struct sockaddr  *ifa_netmask;      /* Interface netmask */
+    struct sockaddr  *ifa_broadaddr;    /* Interface broadcast address */
+    struct sockaddr  *ifa_dstaddr;      /* P2P interface destination */
+    void             *ifa_data;		/* Address specific data */
+.Ed
+.Pp
+The
+.Li ifa_next
+field contains a pointer to the next structure on the list.
+This field is
+.Dv NULL
+in last structure on the list.
+.Pp
+The
+.Li ifa_name
+field contains the interface name.
+.Pp
+The
+.Li ifa_flags
+field contains the interface flags, as set by
+.Xr ifconfig 8
+utility.
+.Pp
+The
+.Li ifa_addr
+field references either the address of the interface or the link level
+address of the interface, if one exists, otherwise it is NULL.
+(The
+.Li sa_family
+field of the
+.Li ifa_addr
+field should be consulted to determine the format of the
+.Li ifa_addr
+address.)
+.Pp
+The
+.Li ifa_netmask
+field references the netmask associated with
+.Li ifa_addr ,
+if one is set, otherwise it is NULL.
+.Pp
+The
+.Li ifa_broadaddr
+field,
+which should only be referenced for non-P2P interfaces,
+references the broadcast address associated with
+.Li ifa_addr ,
+if one exists, otherwise it is NULL.
+.Pp
+The
+.Li ifa_dstaddr
+field references the destination address on a P2P interface,
+if one exists, otherwise it is NULL.
+.Pp
+The
+.Li ifa_data
+field references address family specific data.  For
+.Dv AF_LINK
+addresses it contains a pointer to the
+.Fa struct if_data
+.Pq as defined in include file Aq Pa net/if.h
+which contains various interface attributes and statistics.
+For all other address families, it contains a pointer to the
+.Fa struct ifa_data
+.Pq as defined in include file Aq Pa net/if.h
+which contains per-address interface statistics.
+.Pp
+The data returned by
+.Fn getifaddrs
+is dynamically allocated and should be freed using
+.Fn freeifaddrs
+when no longer needed.
+.Sh RETURN VALUES
+Upon successful completion, a value of 0 is returned.
+Otherwise, a value of -1 is returned and
+.Va errno
+is set to indicate the error.
+.Sh ERRORS
+The
+.Fn getifaddrs
+may fail and set
+.Va errno
+for any of the errors specified for the library routines
+.Xr ioctl 2 ,
+.Xr socket 2 ,
+.Xr malloc 3
+or
+.Xr sysctl 3 .
+.Sh BUGS
+If both
+.Aq Pa net/if.h
+and
+.Aq Pa ifaddrs.h
+are being included,
+.Aq Pa net/if.h
+.Em must
+be included before
+.Aq Pa ifaddrs.h .
+.Sh SEE ALSO
+.Xr ioctl 2 ,
+.Xr socket 2 ,
+.Xr sysctl 3 ,
+.Xr networking 4 ,
+.Xr ifconfig 8
+.Sh HISTORY
+The
+.Nm
+implementation first appeared in BSDI BSD/OS.
diff --git a/lib/libc/net/getifaddrs.c b/lib/libc/net/getifaddrs.c
new file mode 100644
index 0000000..573aada
--- /dev/null
+++ b/lib/libc/net/getifaddrs.c
@@ -0,0 +1,379 @@
+/*	$FreeBSD$	*/
+
+/*
+ * Copyright (c) 1995, 1999
+ *	Berkeley Software Design, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
+ */
+/*
+ * NOTE: SIOCGIFCONF case is not LP64 friendly.  it also does not perform
+ * try-and-error for region size.
+ */
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#ifdef	NET_RT_IFLIST
+#include <sys/param.h>
+#include <net/route.h>
+#include <sys/sysctl.h>
+#include <net/if_dl.h>
+#endif
+
+#include <errno.h>
+#include <ifaddrs.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if !defined(AF_LINK)
+#define	SA_LEN(sa)	sizeof(struct sockaddr)
+#endif
+
+#if !defined(SA_LEN)
+#define	SA_LEN(sa)	(sa)->sa_len
+#endif
+
+#define	SALIGN	(sizeof(long) - 1)
+#define	SA_RLEN(sa)	((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))
+
+#ifndef	ALIGNBYTES
+/*
+ * On systems with a routing socket, ALIGNBYTES should match the value
+ * that the kernel uses when building the messages.
+ */
+#define	ALIGNBYTES	XXX
+#endif
+#ifndef	ALIGN
+#define	ALIGN(p)	(((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
+#endif
+
+#if	_BSDI_VERSION >= 199701
+#define	HAVE_IFM_DATA
+#endif
+
+#if	_BSDI_VERSION >= 199802
+#define	HAVE_IFAM_DATA
+#endif
+
+int
+getifaddrs(struct ifaddrs **pif)
+{
+	int icnt = 1;
+	int dcnt = 0;
+	int ncnt = 0;
+#ifdef	NET_RT_IFLIST
+	int mib[6];
+	size_t needed;
+	char *buf;
+	char *next;
+	struct ifaddrs *cif = 0;
+	char *p, *p0;
+	struct rt_msghdr *rtm;
+	struct if_msghdr *ifm;
+	struct ifa_msghdr *ifam;
+	struct sockaddr_dl *dl;
+	struct sockaddr *sa;
+	struct ifaddrs *ifa, *ift;
+	u_short index = 0;
+#else	/* NET_RT_IFLIST */
+	char buf[1024];
+	int m, sock;
+	struct ifconf ifc;
+	struct ifreq *ifr;
+	struct ifreq *lifr;
+#endif	/* NET_RT_IFLIST */
+	int i;
+	size_t len, alen;
+	char *data;
+	char *names;
+
+#ifdef	NET_RT_IFLIST
+	mib[0] = CTL_NET;
+	mib[1] = PF_ROUTE;
+	mib[2] = 0;             /* protocol */
+	mib[3] = 0;             /* wildcard address family */
+	mib[4] = NET_RT_IFLIST;
+	mib[5] = 0;             /* no flags */
+	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
+		return (-1);
+	if ((buf = malloc(needed)) == NULL)
+		return (-1);
+	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
+		free(buf);
+		return (-1);
+	}
+
+	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
+		rtm = (struct rt_msghdr *)next;
+		if (rtm->rtm_version != RTM_VERSION)
+			continue;
+		switch (rtm->rtm_type) {
+		case RTM_IFINFO:
+			ifm = (struct if_msghdr *)rtm;
+			if (ifm->ifm_addrs & RTA_IFP) {
+				index = ifm->ifm_index;
+				++icnt;
+				dl = (struct sockaddr_dl *)(ifm + 1);
+				dcnt += SA_RLEN((struct sockaddr *)dl) +
+					ALIGNBYTES;
+#ifdef	HAVE_IFM_DATA
+				dcnt += sizeof(ifm->ifm_data);
+#endif	/* HAVE_IFM_DATA */
+				ncnt += dl->sdl_nlen + 1;
+			} else
+				index = 0;
+			break;
+
+		case RTM_NEWADDR:
+			ifam = (struct ifa_msghdr *)rtm;
+			if (index && ifam->ifam_index != index)
+				abort();	/* this cannot happen */
+
+#define	RTA_MASKS	(RTA_NETMASK | RTA_IFA | RTA_BRD)
+			if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
+				break;
+			p = (char *)(ifam + 1);
+			++icnt;
+#ifdef	HAVE_IFAM_DATA
+			dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES;
+#endif	/* HAVE_IFAM_DATA */
+			/* Scan to look for length of address */
+			alen = 0;
+			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
+				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
+				    == 0)
+					continue;
+				sa = (struct sockaddr *)p;
+				len = SA_RLEN(sa);
+				if (i == RTAX_IFA) {
+					alen = len;
+					break;
+				}
+				p += len;
+			}
+			for (p = p0, i = 0; i < RTAX_MAX; i++) {
+				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
+				    == 0)
+					continue;
+				sa = (struct sockaddr *)p;
+				len = SA_RLEN(sa);
+				if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
+					dcnt += alen;
+				else
+					dcnt += len;
+				p += len;
+			}
+			break;
+		}
+	}
+#else	/* NET_RT_IFLIST */
+	ifc.ifc_buf = buf;
+	ifc.ifc_len = sizeof(buf);
+
+	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		return (-1);
+	i =  ioctl(sock, SIOCGIFCONF, (char *)&ifc);
+	close(sock);
+	if (i < 0)
+		return (-1);
+
+	ifr = ifc.ifc_req;
+	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
+
+	while (ifr < lifr) {
+		struct sockaddr *sa;
+
+		sa = &ifr->ifr_addr;
+		++icnt;
+		dcnt += SA_RLEN(sa);
+		ncnt += sizeof(ifr->ifr_name) + 1;
+		
+		ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
+	}
+#endif	/* NET_RT_IFLIST */
+
+	if (icnt + dcnt + ncnt == 1) {
+		*pif = NULL;
+		free(buf);
+		return (0);
+	}
+	data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
+	if (data == NULL) {
+		free(buf);
+		return(-1);
+	}
+
+	ifa = (struct ifaddrs *)data;
+	data += sizeof(struct ifaddrs) * icnt;
+	names = data + dcnt;
+
+	memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
+	ift = ifa;
+
+#ifdef	NET_RT_IFLIST
+	index = 0;
+	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
+		rtm = (struct rt_msghdr *)next;
+		if (rtm->rtm_version != RTM_VERSION)
+			continue;
+		switch (rtm->rtm_type) {
+		case RTM_IFINFO:
+			ifm = (struct if_msghdr *)rtm;
+			if (ifm->ifm_addrs & RTA_IFP) {
+				index = ifm->ifm_index;
+				dl = (struct sockaddr_dl *)(ifm + 1);
+
+				cif = ift;
+				ift->ifa_name = names;
+				ift->ifa_flags = (int)ifm->ifm_flags;
+				memcpy(names, dl->sdl_data, dl->sdl_nlen);
+				names[dl->sdl_nlen] = 0;
+				names += dl->sdl_nlen + 1;
+
+				ift->ifa_addr = (struct sockaddr *)data;
+				memcpy(data, dl, SA_LEN((struct sockaddr *)dl));
+				data += SA_RLEN((struct sockaddr *)dl);
+
+#ifdef	HAVE_IFM_DATA
+				/* ifm_data needs to be aligned */
+				ift->ifa_data = data = (void *)ALIGN(data);
+				memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
+ 				data += sizeof(ifm->ifm_data);
+#else	/* HAVE_IFM_DATA */
+				ift->ifa_data = NULL;
+#endif	/* HAVE_IFM_DATA */
+
+				ift = (ift->ifa_next = ift + 1);
+			} else
+				index = 0;
+			break;
+
+		case RTM_NEWADDR:
+			ifam = (struct ifa_msghdr *)rtm;
+			if (index && ifam->ifam_index != index)
+				abort();	/* this cannot happen */
+
+			if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
+				break;
+			ift->ifa_name = cif->ifa_name;
+			ift->ifa_flags = cif->ifa_flags;
+			ift->ifa_data = NULL;
+			p = (char *)(ifam + 1);
+			/* Scan to look for length of address */
+			alen = 0;
+			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
+				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
+				    == 0)
+					continue;
+				sa = (struct sockaddr *)p;
+				len = SA_RLEN(sa);
+				if (i == RTAX_IFA) {
+					alen = len;
+					break;
+				}
+				p += len;
+			}
+			for (p = p0, i = 0; i < RTAX_MAX; i++) {
+				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
+				    == 0)
+					continue;
+				sa = (struct sockaddr *)p;
+				len = SA_RLEN(sa);
+				switch (i) {
+				case RTAX_IFA:
+					ift->ifa_addr = (struct sockaddr *)data;
+					memcpy(data, p, len);
+					data += len;
+					break;
+
+				case RTAX_NETMASK:
+					ift->ifa_netmask =
+					    (struct sockaddr *)data;
+					if (SA_LEN(sa) == 0) {
+						memset(data, 0, alen);
+						data += alen;
+						break;
+					}
+					memcpy(data, p, len);
+					data += len;
+					break;
+
+				case RTAX_BRD:
+					ift->ifa_broadaddr =
+					    (struct sockaddr *)data;
+					memcpy(data, p, len);
+					data += len;
+					break;
+				}
+				p += len;
+			}
+
+#ifdef	HAVE_IFAM_DATA
+			/* ifam_data needs to be aligned */
+			ift->ifa_data = data = (void *)ALIGN(data);
+			memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data));
+			data += sizeof(ifam->ifam_data);
+#endif	/* HAVE_IFAM_DATA */
+
+			ift = (ift->ifa_next = ift + 1);
+			break;
+		}
+	}
+
+	free(buf);
+#else	/* NET_RT_IFLIST */
+	ifr = ifc.ifc_req;
+	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
+
+	while (ifr < lifr) {
+		struct sockaddr *sa;
+
+		ift->ifa_name = names;
+		names[sizeof(ifr->ifr_name)] = 0;
+		strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name));
+		while (*names++)
+			;
+
+		ift->ifa_addr = (struct sockaddr *)data;
+		sa = &ifr->ifr_addr;
+		memcpy(data, sa, SA_LEN(sa));
+		data += SA_RLEN(sa);
+		
+		ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
+		ift = (ift->ifa_next = ift + 1);
+	}
+#endif	/* NET_RT_IFLIST */
+	if (--ift >= ifa) {
+		ift->ifa_next = NULL;
+		*pif = ifa;
+	} else {
+		*pif = NULL;
+		free(ifa);
+	}
+	return (0);
+}
+
+void
+freeifaddrs(struct ifaddrs *ifp)
+{
+	free(ifp);
+}