diff options
Diffstat (limited to 'lib/libc/net/ifname.c')
| -rw-r--r-- | lib/libc/net/ifname.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/lib/libc/net/ifname.c b/lib/libc/net/ifname.c new file mode 100644 index 0000000..3d3916a --- /dev/null +++ b/lib/libc/net/ifname.c @@ -0,0 +1,212 @@ +/* + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * 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. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``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 THE PROJECT OR CONTRIBUTORS 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. + * + * $FreeBSD$ + */ +/* + * TODO: + * - prototype defs into arpa/inet.h, not net/if.h (bsd-api-new-02) + */ + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/sysctl.h> +#include <net/if.h> +#include <net/route.h> +#include <net/if_dl.h> + +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#define ROUNDUP(a) \ + ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) +#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) + +unsigned int +if_nametoindex(ifname) + const char *ifname; +{ + struct if_nameindex *iff = if_nameindex(), *ifx; + int ret; + + if (iff == NULL) return 0; + ifx = iff; + while (ifx->if_name != NULL) { + if (strcmp(ifx->if_name, ifname) == 0) { + ret = ifx->if_index; + if_freenameindex(iff); + return ret; + } + ifx++; + } + if_freenameindex(iff); + errno = ENXIO; + return 0; +} + +char * +if_indextoname(ifindex, ifname) + unsigned int ifindex; + char *ifname; /* at least IF_NAMESIZE */ +{ + struct if_nameindex *iff = if_nameindex(), *ifx; + char *cp, *dp; + + if (iff == NULL) return NULL; + ifx = iff; + while (ifx->if_index != 0) { + if (ifx->if_index == ifindex) { + cp = ifname; + dp = ifx->if_name; + while ((*cp++ = *dp++)) ; + if_freenameindex(iff); + return (ifname); + } + ifx++; + } + if_freenameindex(iff); + errno = ENXIO; + return NULL; +} + +struct if_nameindex * +if_nameindex() +{ + size_t needed; + int mib[6], i, ifn = 0, off = 0, hlen; + char *buf = NULL, *lim, *next, *cp, *ifbuf = NULL; + struct rt_msghdr *rtm; + struct if_msghdr *ifm; + struct sockaddr *sa; + struct sockaddr_dl *sdl; + struct if_nameindex *ret = NULL; + static int ifxs = 64; /* initial upper limit */ + struct _ifx { + int if_index; + int if_off; + } *ifx = NULL; + + 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 NULL; + if ((buf = malloc(needed)) == NULL) { + errno = ENOMEM; + goto end; + } + /* XXX: we may have allocated too much than necessary */ + if ((ifbuf = malloc(needed)) == NULL) { + errno = ENOMEM; + goto end; + } + if ((ifx = (struct _ifx *)malloc(sizeof(*ifx) * ifxs)) == NULL) { + errno = ENOMEM; + goto end; + } + if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { + /* sysctl has set errno */ + goto end; + } + lim = buf + needed; + for (next = buf; next < lim; next += rtm->rtm_msglen) { + rtm = (struct rt_msghdr *)next; + if (rtm->rtm_version != RTM_VERSION) { + errno = EPROTONOSUPPORT; + goto end; + } + switch (rtm->rtm_type) { + case RTM_IFINFO: + ifm = (struct if_msghdr *)rtm; + ifx[ifn].if_index = ifm->ifm_index; + ifx[ifn].if_off = off; + cp = (char *)(ifm + 1); + for (i = 1; i; i <<= 1) { + if (i & ifm->ifm_addrs) { + sa = (struct sockaddr *)cp; + if (i == RTA_IFP && + sa->sa_family == AF_LINK) { + sdl = (struct sockaddr_dl *)sa; + memcpy(ifbuf + off, + sdl->sdl_data, + sdl->sdl_nlen); + off += sdl->sdl_nlen; + *(ifbuf + off) = '\0'; + off++; + } + ADVANCE(cp, sa); + } + } + if (++ifn == ifxs) { + /* we need more memory */ + struct _ifx *newifx; + + ifxs *= 2; + if ((newifx = (struct _ifx *)malloc(sizeof(*newifx) * ifxs)) == NULL) { + errno = ENOMEM; + goto end; + } + + /* copy and free old data */ + memcpy(newifx, ifx, (sizeof(*ifx) * ifxs) / 2); + free(ifx); + ifx = newifx; + } + } + } + hlen = sizeof(struct if_nameindex) * (ifn + 1); + if ((cp = (char *)malloc(hlen + off)) == NULL) { + errno = ENOMEM; + goto end; + } + bcopy(ifbuf, cp + hlen, off); + ret = (struct if_nameindex *)cp; + for (i = 0; i < ifn; i++) { + ret[i].if_index = ifx[i].if_index; + ret[i].if_name = cp + hlen + ifx[i].if_off; + } + ret[ifn].if_index = 0; + ret[ifn].if_name = NULL; + + end: + if (buf) free(buf); + if (ifbuf) free(ifbuf); + if (ifx) free(ifx); + + return ret; +} + +void if_freenameindex(ptr) + struct if_nameindex *ptr; +{ + free(ptr); +} |
