lib/snmplib/snmp_api.c

   1 /*
   2  * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /**********************************************************************
  10  *
  11  *           Copyright 1997 by Carnegie Mellon University
  12  *
  13  *                       All Rights Reserved
  14  *
  15  * Permission to use, copy, modify, and distribute this software and its
  16  * documentation for any purpose and without fee is hereby granted,
  17  * provided that the above copyright notice appear in all copies and that
  18  * both that copyright notice and this permission notice appear in
  19  * supporting documentation, and that the name of CMU not be
  20  * used in advertising or publicity pertaining to distribution of the
  21  * software without specific, written prior permission.
  22  *
  23  * CMU DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
  24  * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
  25  * CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
  26  * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  27  * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  28  * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  29  * SOFTWARE.
  30  *
  31  **********************************************************************/
  32
  33 #include "squid.h"
  34
  35 #if HAVE_UNISTD_H
  36 #include <unistd.h>
  37 #endif
  38 #if HAVE_STDLIB_H
  39 #include <stdlib.h>
  40 #endif
  41 #if HAVE_SYS_TYPES_H
  42 #include <sys/types.h>
  43 #endif
  44 #if HAVE_CTYPE_H
  45 #include <ctype.h>
  46 #endif
  47 #if HAVE_GNUMALLOC_H
  48 #include <gnumalloc.h>
  49 #elif HAVE_MALLOC_H
  50 #include <malloc.h>
  51 #endif
  52 #if HAVE_MEMORY_H
  53 #include <memory.h>
  54 #endif
  55 #if HAVE_STRING_H
  56 #include <string.h>
  57 #endif
  58 #if HAVE_STRINGS_H
  59 #include <strings.h>
  60 #endif
  61 #if HAVE_BSTRING_H
  62 #include <bstring.h>
  63 #endif
  64 #if HAVE_SYS_SOCKET_H
  65 #include <sys/socket.h>
  66 #endif
  67 #if HAVE_NETINET_IN_H
  68 #include <netinet/in.h>
  69 #endif
  70 #if HAVE_ARPA_INET_H
  71 #include <arpa/inet.h>
  72 #endif
  73 #if HAVE_SYS_TIME_H
  74 #include <sys/time.h>
  75 #endif
  76 #if HAVE_NETDB_H
  77 #include <netdb.h>
  78 #endif
  79
  80 #include "asn1.h"
  81 #include "snmp.h"
  82
  83 #include "snmp-internal.h"
  84 #include "snmp_error.h"
  85 #include "snmp_impl.h"
  86 #include "snmp_msg.h"
  87 #include "snmp_pdu.h"
  88 #include "snmp_session.h"
  89 #include "snmp_vars.h"
  90
  91 #include "snmp_api.h"
  92 #include "snmp_api_error.h"
  93 #include "snmp_api_util.h"
  94
  95 #include "util.h"
  96
  97 /**********************************************************************/
  98
  99 /*
 100  * Takes a session and a pdu and serializes the ASN PDU into the area
 101  * pointed to by packet.  out_length is the size of the data area available.
 102  * Returns the length of the encoded packet in out_length.  If an error
 103  * occurs, -1 is returned.  If all goes well, 0 is returned.
 104  */
 105 int
 106 snmp_build(struct snmp_session *session, struct snmp_pdu *pdu, u_char *packet, int *out_length)
 107 {
 108     u_char *bufp;
 109
 110     bufp = snmp_msg_Encode(packet, out_length,
 111                            session->community, session->community_len,
 112                            session->Version,
 113                            pdu);
 114     snmplib_debug(8, "LIBSNMP: snmp_build():  Packet len %d (requid %d)\n",
 115                   *out_length, pdu->reqid);
 116
 117     if (bufp == NULL)
 118         return (-1);
 119
 120     return (0);
 121 }
 122
 123 /*
 124  * Parses the packet received on the input session, and places the data into
 125  * the input pdu.  length is the length of the input packet.  If any errors
 126  * are encountered, NULL is returned.  If not, the community is.
 127  */
 128 u_char *
 129 snmp_parse(struct snmp_session * session,
 130            struct snmp_pdu * pdu,
 131            u_char * data,
 132            int length)
 133 {
 134     u_char Community[128];
 135     u_char *bufp;
 136     int CommunityLen = 128;
 137
 138     /* Decode the entire message. */
 139     data = snmp_msg_Decode(data, &length,
 140                            Community, &CommunityLen,
 141                            &session->Version, pdu);
 142     if (data == NULL)
 143         return (NULL);
 144
 145     bufp = (u_char *) xmalloc(CommunityLen + 1);
 146     if (bufp == NULL)
 147         return (NULL);
 148
 149     strncpy((char *) bufp, (char *) Community, CommunityLen);
 150     bufp[CommunityLen] = '\0';
 151
 152     session->community = bufp;
 153     session->community_len = CommunityLen;
 154
 155     return (bufp);
 156 }
 157