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/* $OpenBSD: if_nameindex.c,v 1.13 2016/12/16 17:44:59 krw Exp $ */ |
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/* $KAME: if_nameindex.c,v 1.7 2000/11/24 08:17:20 itojun Exp $ */ |
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/*- |
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* Copyright (c) 2015 Claudio Jeker <claudio@openbsd.org> |
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* Copyright (c) 1997, 2000 |
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* Berkeley Software Design, Inc. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* |
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* BSDI Id: if_nameindex.c,v 2.3 2000/04/17 22:38:05 dab Exp |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/sysctl.h> |
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#include <net/if.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <errno.h> |
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/* |
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* From RFC 2553: |
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* |
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* 4.3 Return All Interface Names and Indexes |
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* |
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* The if_nameindex structure holds the information about a single |
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* interface and is defined as a result of including the <net/if.h> |
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* header. |
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* |
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* struct if_nameindex { |
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* unsigned int if_index; |
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* char *if_name; |
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* }; |
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* |
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* The final function returns an array of if_nameindex structures, one |
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* structure per interface. |
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* |
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* struct if_nameindex *if_nameindex(void); |
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* |
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* The end of the array of structures is indicated by a structure with |
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* an if_index of 0 and an if_name of NULL. The function returns a NULL |
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* pointer upon an error, and would set errno to the appropriate value. |
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* |
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* The memory used for this array of structures along with the interface |
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* names pointed to by the if_name members is obtained dynamically. |
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* This memory is freed by the next function. |
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* |
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* 4.4. Free Memory |
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* |
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* The following function frees the dynamic memory that was allocated by |
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* if_nameindex(). |
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* |
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* #include <net/if.h> |
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* |
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* void if_freenameindex(struct if_nameindex *ptr); |
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* |
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* The argument to this function must be a pointer that was returned by |
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* if_nameindex(). |
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*/ |
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struct if_nameindex * |
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if_nameindex(void) |
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{ |
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struct if_nameindex_msg *ifnm = NULL; |
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struct if_nameindex *ifni = NULL, *ifni2; |
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char *cp; |
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size_t needed; |
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unsigned int ni, i; |
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int mib[6]; |
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mib[0] = CTL_NET; |
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mib[1] = PF_ROUTE; |
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mib[2] = 0; /* protocol */ |
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mib[3] = 0; /* not used */ |
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mib[4] = NET_RT_IFNAMES; |
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mib[5] = 0; /* no flags */ |
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while (1) { |
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struct if_nameindex_msg *buf = NULL; |
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if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1) |
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goto out; |
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if (needed == 0) |
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break; |
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if ((buf = realloc(ifnm, needed)) == NULL) |
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goto out; |
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ifnm = buf; |
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if (sysctl(mib, 6, ifnm, &needed, NULL, 0) == -1) { |
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if (errno == ENOMEM) |
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continue; |
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goto out; |
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} |
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break; |
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} |
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/* |
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* Allocate a chunk of memory, use the first part for the array of |
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* structures, and the last part for the strings. |
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*/ |
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ni = needed / sizeof(*ifnm); |
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ifni = calloc(ni + 1, sizeof(struct if_nameindex) + IF_NAMESIZE); |
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if (ifni == NULL) |
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goto out; |
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cp = (char *)(ifni + (ni + 1)); |
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ifni2 = ifni; |
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for (i = 0; i < ni; i++) { |
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ifni2->if_index = ifnm[i].if_index; |
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/* don't care about truncation */ |
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strlcpy(cp, ifnm[i].if_name, IF_NAMESIZE); |
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ifni2->if_name = cp; |
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ifni2++; |
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cp += IF_NAMESIZE; |
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} |
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/* Finally, terminate the array. */ |
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ifni2->if_index = 0; |
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ifni2->if_name = NULL; |
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out: |
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free(ifnm); |
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return ifni; |
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} |
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void |
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if_freenameindex(struct if_nameindex *ptr) |
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{ |
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free(ptr); |
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} |
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DEF_WEAK(if_nameindex); |
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DEF_WEAK(if_freenameindex); |