/* * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by John Robert LoVerso. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * This implementation has been influenced by the CMU SNMP release, * by Steve Waldbusser. However, this shares no code with that system. * Additional ASN.1 insight gained from Marshall T. Rose's _The_Open_Book_. * Earlier forms of this implementation were derived and/or inspired by an * awk script originally written by C. Philip Wood of LANL (but later * heavily modified by John Robert LoVerso). The copyright notice for * that work is preserved below, even though it may not rightly apply * to this file. * * This started out as a very simple program, but the incremental decoding * (into the BE structure) complicated things. * # Los Alamos National Laboratory # # Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997 # This software was produced under a U.S. Government contract # (W-7405-ENG-36) by Los Alamos National Laboratory, which is # operated by the University of California for the U.S. Department # of Energy. The U.S. Government is licensed to use, reproduce, # and distribute this software. Permission is granted to the # public to copy and use this software without charge, provided # that this Notice and any statement of authorship are reproduced # on all copies. Neither the Government nor the University makes # any warranty, express or implied, or assumes any liability or # responsibility for the use of this software. # @(#)snmp.awk.x 1.1 (LANL) 1/15/90 */ #ifndef lint static const char rcsid[] = "@(#) $Header: /cvs/OpenBSD/src/usr.sbin/tcpdump/print-snmp.c,v 1.6 1999/09/16 20:58:47 brad Exp $ (LBL)"; #endif #include #include #include #include #include #include "interface.h" #include "addrtoname.h" /* * Universal ASN.1 types * (we only care about the tag values for those allowed in the Internet SMI) */ char *Universal[] = { "U-0", "Boolean", "Integer", #define INTEGER 2 "Bitstring", "String", #define STRING 4 "Null", #define ASN_NULL 5 "ObjID", #define OBJECTID 6 "ObjectDes", "U-8","U-9","U-10","U-11", /* 8-11 */ "U-12","U-13","U-14","U-15", /* 12-15 */ "Sequence", #define SEQUENCE 16 "Set" }; /* * Application-wide ASN.1 types from the Internet SMI and their tags */ char *Application[] = { "IpAddress", #define IPADDR 0 "Counter", #define COUNTER 1 "Gauge", #define GAUGE 2 "TimeTicks", #define TIMETICKS 3 "Opaque" }; /* * Context-specific ASN.1 types for the SNMP PDUs and their tags */ char *Context[] = { "GetRequest", #define GETREQ 0 "GetNextRequest", #define GETNEXTREQ 1 "GetResponse", #define GETRESP 2 "SetRequest", #define SETREQ 3 "Trap" #define TRAP 4 }; /* * Private ASN.1 types * The Internet SMI does not specify any */ char *Private[] = { "P-0" }; /* * error-status values for any SNMP PDU */ char *ErrorStatus[] = { "noError", "tooBig", "noSuchName", "badValue", "readOnly", "genErr" }; #define DECODE_ErrorStatus(e) \ ( e >= 0 && e <= sizeof(ErrorStatus)/sizeof(ErrorStatus[0]) \ ? ErrorStatus[e] : (sprintf(errbuf, "err=%u", e), errbuf)) /* * generic-trap values in the SNMP Trap-PDU */ char *GenericTrap[] = { "coldStart", "warmStart", "linkDown", "linkUp", "authenticationFailure", "egpNeighborLoss", "enterpriseSpecific" #define GT_ENTERPRISE 7 }; #define DECODE_GenericTrap(t) \ ( t >= 0 && t <= sizeof(GenericTrap)/sizeof(GenericTrap[0]) \ ? GenericTrap[t] : (sprintf(buf, "gt=%d", t), buf)) /* * ASN.1 type class table * Ties together the preceding Universal, Application, Context, and Private * type definitions. */ #define defineCLASS(x) { "x", x, sizeof(x)/sizeof(x[0]) } /* not ANSI-C */ struct { char *name; char **Id; int numIDs; } Class[] = { defineCLASS(Universal), #define UNIVERSAL 0 defineCLASS(Application), #define APPLICATION 1 defineCLASS(Context), #define CONTEXT 2 defineCLASS(Private), #define PRIVATE 3 }; /* * defined forms for ASN.1 types */ char *Form[] = { "Primitive", #define PRIMITIVE 0 "Constructed", #define CONSTRUCTED 1 }; /* * A structure for the OID tree for the compiled-in MIB. * This is stored as a general-order tree. */ struct obj { char *desc; /* name of object */ u_char oid; /* sub-id following parent */ u_char type; /* object type (unused) */ struct obj *child, *next; /* child and next sibling pointers */ } *objp = NULL; /* * Include the compiled in SNMP MIB. "mib.h" is produced by feeding * RFC-1156 format files into "makemib". "mib.h" MUST define at least * a value for `mibroot'. * * In particular, this is gross, as this is including initialized structures, * and by right shouldn't be an "include" file. */ #include "mib.h" /* * This defines a list of OIDs which will be abbreviated on output. * Currently, this includes the prefixes for the Internet MIB, the * private enterprises tree, and the experimental tree. */ struct obj_abrev { char *prefix; /* prefix for this abrev */ struct obj *node; /* pointer into object table */ char *oid; /* ASN.1 encoded OID */ } obj_abrev_list[] = { #ifndef NO_ABREV_MIB /* .iso.org.dod.internet.mgmt.mib */ { "", &_mib_obj, "\53\6\1\2\1" }, #endif #ifndef NO_ABREV_ENTER /* .iso.org.dod.internet.private.enterprises */ { "E:", &_enterprises_obj, "\53\6\1\4\1" }, #endif #ifndef NO_ABREV_EXPERI /* .iso.org.dod.internet.experimental */ { "X:", &_experimental_obj, "\53\6\1\3" }, #endif { 0,0,0 } }; /* * This is used in the OID print routine to walk down the object tree * rooted at `mibroot'. */ #define OBJ_PRINT(o, suppressdot) \ { \ if (objp) { \ do { \ if ((o) == objp->oid) \ break; \ } while ((objp = objp->next) != NULL); \ } \ if (objp) { \ printf(suppressdot?"%s":".%s", objp->desc); \ objp = objp->child; \ } else \ printf(suppressdot?"%u":".%u", (o)); \ } /* * This is the definition for the Any-Data-Type storage used purely for * temporary internal representation while decoding an ASN.1 data stream. */ struct be { u_int32_t asnlen; union { caddr_t raw; int32_t integer; u_int32_t uns; const u_char *str; } data; u_short id; u_char form, class; /* tag info */ u_char type; #define BE_ANY 255 #define BE_NONE 0 #define BE_NULL 1 #define BE_OCTET 2 #define BE_OID 3 #define BE_INT 4 #define BE_UNS 5 #define BE_STR 6 #define BE_SEQ 7 #define BE_INETADDR 8 #define BE_PDU 9 }; /* * Defaults for SNMP PDU components */ #define DEF_COMMUNITY "public" #define DEF_VERSION 0 /* * constants for ASN.1 decoding */ #define OIDMUX 40 #define ASNLEN_INETADDR 4 #define ASN_SHIFT7 7 #define ASN_SHIFT8 8 #define ASN_BIT8 0x80 #define ASN_LONGLEN 0x80 #define ASN_ID_BITS 0x1f #define ASN_FORM_BITS 0x20 #define ASN_FORM_SHIFT 5 #define ASN_CLASS_BITS 0xc0 #define ASN_CLASS_SHIFT 6 #define ASN_ID_EXT 0x1f /* extension ID in tag field */ /* * truncated==1 means the packet was complete, but we don't have all of * it to decode. */ static int truncated; #define ifNotTruncated if (truncated) fputs("[|snmp]", stdout); else /* * This decodes the next ASN.1 object in the stream pointed to by "p" * (and of real-length "len") and stores the intermediate data in the * provided BE object. * * This returns -l if it fails (i.e., the ASN.1 stream is not valid). * O/w, this returns the number of bytes parsed from "p". */ static int asn1_parse(register const u_char *p, u_int len, struct be *elem) { u_char form, class, id; int i, hdr; elem->asnlen = 0; elem->type = BE_ANY; if (len < 1) { ifNotTruncated puts("[nothing to parse], stdout"); return -1; } /* * it would be nice to use a bit field, but you can't depend on them. * +---+---+---+---+---+---+---+---+ * + class |frm| id | * +---+---+---+---+---+---+---+---+ * 7 6 5 4 3 2 1 0 */ id = *p & ASN_ID_BITS; /* lower 5 bits, range 00-1f */ #ifdef notdef form = (*p & 0xe0) >> 5; /* move upper 3 bits to lower 3 */ class = form >> 1; /* bits 7&6 -> bits 1&0, range 0-3 */ form &= 0x1; /* bit 5 -> bit 0, range 0-1 */ #else form = (u_char)(*p & ASN_FORM_BITS) >> ASN_FORM_SHIFT; class = (u_char)(*p & ASN_CLASS_BITS) >> ASN_CLASS_SHIFT; #endif elem->form = form; elem->class = class; elem->id = id; if (vflag) printf("|%.2x", *p); p++; len--; hdr = 1; /* extended tag field */ if (id == ASN_ID_EXT) { for (id = 0; *p & ASN_BIT8 && len > 0; len--, hdr++, p++) { if (vflag) printf("|%.2x", *p); id = (id << 7) | (*p & ~ASN_BIT8); } if (len == 0 && *p & ASN_BIT8) { ifNotTruncated fputs("[Xtagfield?]", stdout); return -1; } elem->id = id = (id << 7) | *p; --len; ++hdr; ++p; } if (len < 1) { ifNotTruncated fputs("[no asnlen]", stdout); return -1; } elem->asnlen = *p; if (vflag) printf("|%.2x", *p); p++; len--; hdr++; if (elem->asnlen & ASN_BIT8) { int noct = elem->asnlen % ASN_BIT8; elem->asnlen = 0; if (len < noct) { ifNotTruncated printf("[asnlen? %d<%d]", len, noct); return -1; } for (; noct-- > 0; len--, hdr++) { if (vflag) printf("|%.2x", *p); elem->asnlen = (elem->asnlen << ASN_SHIFT8) | *p++; } } if (len < elem->asnlen) { if (!truncated) { printf("[len%dasnlen); return -1; } /* maybe should check at least 4? */ elem->asnlen = len; } if (form >= sizeof(Form)/sizeof(Form[0])) { ifNotTruncated printf("[form?%d]", form); return -1; } if (class >= sizeof(Class)/sizeof(Class[0])) { ifNotTruncated printf("[class?%c/%d]", *Form[form], class); return -1; } if ((int)id >= Class[class].numIDs) { ifNotTruncated printf("[id?%c/%s/%d]", *Form[form], Class[class].name, id); return -1; } switch (form) { case PRIMITIVE: switch (class) { case UNIVERSAL: switch (id) { case STRING: elem->type = BE_STR; elem->data.str = p; break; case INTEGER: { register int32_t data; elem->type = BE_INT; data = 0; if (*p & ASN_BIT8) /* negative */ data = -1; for (i = elem->asnlen; i-- > 0; p++) data = (data << ASN_SHIFT8) | *p; elem->data.integer = data; break; } case OBJECTID: elem->type = BE_OID; elem->data.raw = (caddr_t)p; break; case ASN_NULL: elem->type = BE_NULL; elem->data.raw = NULL; break; default: elem->type = BE_OCTET; elem->data.raw = (caddr_t)p; printf("[P/U/%s]", Class[class].Id[id]); break; } break; case APPLICATION: switch (id) { case IPADDR: elem->type = BE_INETADDR; elem->data.raw = (caddr_t)p; break; case COUNTER: case GAUGE: case TIMETICKS: { register u_int32_t data; elem->type = BE_UNS; data = 0; for (i = elem->asnlen; i-- > 0; p++) data = (data << 8) + *p; elem->data.uns = data; break; } default: elem->type = BE_OCTET; elem->data.raw = (caddr_t)p; printf("[P/A/%s]", Class[class].Id[id]); break; } break; default: elem->type = BE_OCTET; elem->data.raw = (caddr_t)p; printf("[P/%s/%s]", Class[class].name, Class[class].Id[id]); break; } break; case CONSTRUCTED: switch (class) { case UNIVERSAL: switch (id) { case SEQUENCE: elem->type = BE_SEQ; elem->data.raw = (caddr_t)p; break; default: elem->type = BE_OCTET; elem->data.raw = (caddr_t)p; printf("C/U/%s", Class[class].Id[id]); break; } break; case CONTEXT: elem->type = BE_PDU; elem->data.raw = (caddr_t)p; break; default: elem->type = BE_OCTET; elem->data.raw = (caddr_t)p; printf("C/%s/%s", Class[class].name, Class[class].Id[id]); break; } break; } p += elem->asnlen; len -= elem->asnlen; return elem->asnlen + hdr; } /* * Display the ASN.1 object represented by the BE object. * This used to be an integral part of asn1_parse() before the intermediate * BE form was added. */ static void asn1_print(struct be *elem) { u_char *p = (u_char *)elem->data.raw; u_int32_t asnlen = elem->asnlen; int i; switch (elem->type) { case BE_OCTET: for (i = asnlen; i-- > 0; p++); printf("_%.2x", *p); break; case BE_NULL: break; case BE_OID: { int o = 0, first = -1, i = asnlen; if (!nflag && asnlen > 2) { struct obj_abrev *a = &obj_abrev_list[0]; for (; a->node; a++) { if (!memcmp(a->oid, (char *)p, strlen(a->oid))) { objp = a->node->child; i -= strlen(a->oid); p += strlen(a->oid); fputs(a->prefix, stdout); first = 1; break; } } } for (; i-- > 0; p++) { o = (o << ASN_SHIFT7) + (*p & ~ASN_BIT8); if (*p & ASN_LONGLEN) continue; /* * first subitem encodes two items with 1st*OIDMUX+2nd */ if (first < 0) { if (!nflag) objp = mibroot; first = 0; OBJ_PRINT(o/OIDMUX, first); o %= OIDMUX; } OBJ_PRINT(o, first); if (--first < 0) first = 0; o = 0; } break; } case BE_INT: printf("%d", elem->data.integer); break; case BE_UNS: printf("%d", elem->data.uns); break; case BE_STR: { register int printable = 1, first = 1; const u_char *p = elem->data.str; for (i = asnlen; printable && i-- > 0; p++) printable = isprint(*p) || isspace(*p); p = elem->data.str; if (printable) { putchar('"'); (void)fn_print(p, p + asnlen); putchar('"'); } else for (i = asnlen; i-- > 0; p++) { printf(first ? "%.2x" : "_%.2x", *p); first = 0; } break; } case BE_SEQ: printf("Seq(%u)", elem->asnlen); break; case BE_INETADDR: { char sep; if (asnlen != ASNLEN_INETADDR) printf("[inetaddr len!=%d]", ASNLEN_INETADDR); sep='['; for (i = asnlen; i-- > 0; p++) { printf("%c%u", sep, *p); sep='.'; } putchar(']'); break; } case BE_PDU: printf("%s(%u)", Class[CONTEXT].Id[elem->id], elem->asnlen); break; case BE_ANY: fputs("[BE_ANY!?]", stdout); break; default: fputs("[be!?]", stdout); break; } } #ifdef notdef /* * This is a brute force ASN.1 printer: recurses to dump an entire structure. * This will work for any ASN.1 stream, not just an SNMP PDU. * * By adding newlines and spaces at the correct places, this would print in * Rose-Normal-Form. * * This is not currently used. */ static void asn1_decode(u_char *p, u_int length) { struct be elem; int i = 0; while (i >= 0 && length > 0) { i = asn1_parse(p, length, &elem); if (i >= 0) { fputs(" ", stdout); asn1_print(&elem); if (elem.type == BE_SEQ || elem.type == BE_PDU) { fputs(" {", stdout); asn1_decode(elem.data.raw, elem.asnlen); fputs(" }", stdout); } length -= i; p += i; } } } #endif /* * General SNMP header * SEQUENCE { * version INTEGER {version-1(0)}, * community OCTET STRING, * data ANY -- PDUs * } * PDUs for all but Trap: (see rfc1157 from page 15 on) * SEQUENCE { * request-id INTEGER, * error-status INTEGER, * error-index INTEGER, * varbindlist SEQUENCE OF * SEQUENCE { * name ObjectName, * value ObjectValue * } * } * PDU for Trap: * SEQUENCE { * enterprise OBJECT IDENTIFIER, * agent-addr NetworkAddress, * generic-trap INTEGER, * specific-trap INTEGER, * time-stamp TimeTicks, * varbindlist SEQUENCE OF * SEQUENCE { * name ObjectName, * value ObjectValue * } * } */ /* * Decode SNMP varBind */ static void varbind_print(u_char pduid, const u_char *np, u_int length, int error) { struct be elem; int count = 0, ind; /* Sequence of varBind */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_SEQ) { fputs("[!SEQ of varbind]", stdout); asn1_print(&elem); return; } if (count < length) printf("[%d extra after SEQ of varbind]", length - count); /* descend */ length = elem.asnlen; np = (u_char *)elem.data.raw; for (ind = 1; length > 0; ind++) { const u_char *vbend; u_int vblength; if (!error || ind == error) fputs(" ", stdout); /* Sequence */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_SEQ) { fputs("[!varbind]", stdout); asn1_print(&elem); return; } vbend = np + count; vblength = length - count; /* descend */ length = elem.asnlen; np = (u_char *)elem.data.raw; /* objName (OID) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_OID) { fputs("[objName!=OID]", stdout); asn1_print(&elem); return; } if (!error || ind == error) asn1_print(&elem); length -= count; np += count; if (pduid != GETREQ && pduid != GETNEXTREQ && !error) fputs("=", stdout); /* objVal (ANY) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (pduid == GETREQ || pduid == GETNEXTREQ) { if (elem.type != BE_NULL) { fputs("[objVal!=NULL]", stdout); asn1_print(&elem); } } else if (error && ind == error && elem.type != BE_NULL) fputs("[err objVal!=NULL]", stdout); if (!error || ind == error) asn1_print(&elem); length = vblength; np = vbend; } } /* * Decode SNMP PDUs: GetRequest, GetNextRequest, GetResponse, and SetRequest */ static void snmppdu_print(u_char pduid, const u_char *np, u_int length) { struct be elem; int count = 0, error; /* reqId (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[reqId!=INT]", stdout); asn1_print(&elem); return; } /* ignore the reqId */ length -= count; np += count; /* errorStatus (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[errorStatus!=INT]", stdout); asn1_print(&elem); return; } error = 0; if ((pduid == GETREQ || pduid == GETNEXTREQ) && elem.data.integer != 0) { char errbuf[10]; printf("[errorStatus(%s)!=0]", DECODE_ErrorStatus(elem.data.integer)); } else if (elem.data.integer != 0) { char errbuf[10]; printf(" %s", DECODE_ErrorStatus(elem.data.integer)); error = elem.data.integer; } length -= count; np += count; /* errorIndex (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[errorIndex!=INT]", stdout); asn1_print(&elem); return; } if ((pduid == GETREQ || pduid == GETNEXTREQ) && elem.data.integer != 0) printf("[errorIndex(%d)!=0]", elem.data.integer); else if (elem.data.integer != 0) { if (!error) printf("[errorIndex(%d) w/o errorStatus]", elem.data.integer); else { printf("@%d", elem.data.integer); error = elem.data.integer; } } else if (error) { fputs("[errorIndex==0]", stdout); error = 0; } length -= count; np += count; varbind_print(pduid, np, length, error); return; } /* * Decode SNMP Trap PDU */ static void trap_print(const u_char *np, u_int length) { struct be elem; int count = 0, generic; putchar(' '); /* enterprise (oid) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_OID) { fputs("[enterprise!=OID]", stdout); asn1_print(&elem); return; } asn1_print(&elem); length -= count; np += count; putchar(' '); /* agent-addr (inetaddr) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INETADDR) { fputs("[agent-addr!=INETADDR]", stdout); asn1_print(&elem); return; } asn1_print(&elem); length -= count; np += count; /* generic-trap (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[generic-trap!=INT]", stdout); asn1_print(&elem); return; } generic = elem.data.integer; { char buf[10]; printf(" %s", DECODE_GenericTrap(generic)); } length -= count; np += count; /* specific-trap (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[specific-trap!=INT]", stdout); asn1_print(&elem); return; } if (generic != GT_ENTERPRISE) { if (elem.data.integer != 0) printf("[specific-trap(%d)!=0]", elem.data.integer); } else printf(" s=%d", elem.data.integer); length -= count; np += count; putchar(' '); /* time-stamp (TimeTicks) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_UNS) { /* XXX */ fputs("[time-stamp!=TIMETICKS]", stdout); asn1_print(&elem); return; } asn1_print(&elem); length -= count; np += count; varbind_print (TRAP, np, length, 0); return; } /* * Decode SNMP header and pass on to PDU printing routines */ void snmp_print(const u_char *np, u_int length) { struct be elem, pdu; int count = 0; truncated = 0; /* truncated packet? */ if (np + length > snapend) { truncated = 1; length = snapend - np; } putchar(' '); /* initial Sequence */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_SEQ) { fputs("[!init SEQ]", stdout); asn1_print(&elem); return; } if (count < length) printf("[%d extra after iSEQ]", length - count); /* descend */ length = elem.asnlen; np = (u_char *)elem.data.raw; /* Version (Integer) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_INT) { fputs("[version!=INT]", stdout); asn1_print(&elem); return; } /* only handle version==0 */ if (elem.data.integer != DEF_VERSION) { printf("[version(%d)!=0]", elem.data.integer); return; } length -= count; np += count; /* Community (String) */ if ((count = asn1_parse(np, length, &elem)) < 0) return; if (elem.type != BE_STR) { fputs("[comm!=STR]", stdout); asn1_print(&elem); return; } /* default community */ if (strncmp((char *)elem.data.str, DEF_COMMUNITY, sizeof(DEF_COMMUNITY) - 1)) /* ! "public" */ printf("C=%.*s ", (int)elem.asnlen, elem.data.str); length -= count; np += count; /* PDU (Context) */ if ((count = asn1_parse(np, length, &pdu)) < 0) return; if (pdu.type != BE_PDU) { fputs("[no PDU]", stdout); return; } if (count < length) printf("[%d extra after PDU]", length - count); asn1_print(&pdu); /* descend into PDU */ length = pdu.asnlen; np = (u_char *)pdu.data.raw; switch (pdu.id) { case TRAP: trap_print(np, length); break; case GETREQ: case GETNEXTREQ: case GETRESP: case SETREQ: snmppdu_print(pdu.id, np, length); break; } return; }