add getifaddrs(3), from bsdi4.

this will help future apps from complexity of SIOCGIFCONF.
NOTE: getifaddrs(3) uses sysctl interface, not SIOCGIFCONF.

3 files changed, 539 insertions, 5 deletions

diff --git a/src/lib/libc/net/Makefile.inc b/src/lib/libc/net/Makefile.inc
index 7174d68220..7504a3e195 100644
--- a/src/lib/libc/net/Makefile.inc
+++ b/src/lib/libc/net/Makefile.inc
@@ -1,4 +1,4 @@
-#       $OpenBSD: Makefile.inc,v 1.28 2000/01/27 05:18:46 itojun Exp $
+#       $OpenBSD: Makefile.inc,v 1.29 2000/02/23 06:55:58 itojun Exp $
 
 # net sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_ARCH}/net ${LIBCSRCDIR}/net
@@ -6,7 +6,7 @@
 CFLAGS+=-DRESOLVSORT
 
 SRCS+=  base64.c freeaddrinfo.c gai_strerror.c getaddrinfo.c gethostnamadr.c \
-        getnameinfo.c getnetbyaddr.c getnetbyname.c getnetent.c \
+        getifaddrs.c getnameinfo.c getnetbyaddr.c getnetbyname.c getnetent.c \
         getnetnamadr.c getproto.c getprotoent.c getprotoname.c \
         getservbyname.c getservbyport.c getservent.c herror.c \
         if_indextoname.c if_nameindex.c if_nametoindex.c inet_addr.c \
@@ -28,9 +28,9 @@ SRCS+=	ip6opt.c rthdr.c vars6.c
 
 .include "${LIBCSRCDIR}/arch/${MACHINE_ARCH}/net/Makefile.inc"
 
-MAN+=   byteorder.3 ethers.3 getaddrinfo.3 gethostbyname.3 getnameinfo.3 \
-        getnetent.3 getprotoent.3 getservent.3 inet.3 if_indextoname.3 \
-        inet_net.3 iso_addr.3 link_addr.3 ns.3 ipx.3 \
+MAN+=   byteorder.3 ethers.3 getaddrinfo.3 gethostbyname.3 getifaddrs.3 \
+        getnameinfo.3 getnetent.3 getprotoent.3 getservent.3 inet.3 \
+        if_indextoname.3 inet_net.3 iso_addr.3 link_addr.3 ns.3 ipx.3 \
         rcmd.3 rcmdsh.3 resolver.3 net_addrcmp.3 \
         inet6_option_space.3 inet6_rthdr_space.3
 
diff --git a/src/lib/libc/net/getifaddrs.3 b/src/lib/libc/net/getifaddrs.3
new file mode 100644
index 0000000000..68c12b552a
--- /dev/null
+++ b/src/lib/libc/net/getifaddrs.3
@@ -0,0 +1,161 @@
+.\"     $OpenBSD: getifaddrs.3,v 1.1 2000/02/23 06:55:58 itojun Exp $
+.\"     BSDI    getifaddrs.3,v 2.4 1999/03/15 20:57:20 jch 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"
+.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 free
+.Pq see Xr free 3
+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/src/lib/libc/net/getifaddrs.c b/src/lib/libc/net/getifaddrs.c
new file mode 100644
index 0000000000..9537405667
--- /dev/null
+++ b/src/lib/libc/net/getifaddrs.c
@@ -0,0 +1,373 @@
+/*      $OpenBSD: getifaddrs.c,v 1.1 2000/02/23 06:55:58 itojun 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.
+ *
+ *      BSDI getifaddrs.c,v 2.11 1999/03/15 20:57:20 jch 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);
+}