X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/56bcff3da9fa58a9b3f8132d71a2fd9497ef799e..refs/heads/master:/print-zeromq.c diff --git a/print-zeromq.c b/print-zeromq.c index 10ca2cc4..82010475 100644 --- a/print-zeromq.c +++ b/print-zeromq.c @@ -1,7 +1,4 @@ /* - * This file implements decoding of ZeroMQ network protocol(s). - * - * * Copyright (c) 2013 The TCPDUMP project * All rights reserved. * @@ -28,22 +25,34 @@ * POSSIBILITY OF SUCH DAMAGE. */ -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif +/* \summary: ZeroMQ Message Transport Protocol (ZMTP) printer */ +/* specification: https://rfc.zeromq.org/spec/13/ */ -#include +#include -#include +#include "netdissect-stdinc.h" -#include "interface.h" +#include "netdissect.h" #include "extract.h" + /* Maximum number of ZMTP/1.0 frame body bytes (without the flags) to dump in * hex and ASCII under a single "-v" flag. */ #define VBYTES 128 +static const struct tok flags_bm[] = { + { 0x01, "MORE" }, + { 0x02, "R1" }, + { 0x04, "R2" }, + { 0x08, "R3" }, + { 0x10, "R4" }, + { 0x20, "R5" }, + { 0x40, "R6" }, + { 0x80, "R7" }, + { 0, NULL } +}; + /* * Below is an excerpt from the "13/ZMTP" specification: * @@ -75,74 +84,134 @@ */ static const u_char * -zmtp1_print_frame(const u_char *cp, const u_char *ep) { - u_int64_t body_len_declared, body_len_captured, header_len; - u_int8_t flags; +zmtp1_print_frame(netdissect_options *ndo, const u_char *cp, const u_char *ep) +{ + uint64_t body_len_declared, body_len_captured, header_len; + uint8_t flags; - printf("\n\t"); - TCHECK2(*cp, 1); /* length/0xFF */ + ND_PRINT("\n\t"); - if (cp[0] != 0xFF) { + if (GET_U_1(cp) != 0xFF) { /* length/0xFF */ header_len = 1; /* length */ - body_len_declared = cp[0]; - if (body_len_declared == 0) - return cp + header_len; /* skip to next frame */ - printf(" frame flags+body (8-bit) length %u", cp[0]); - TCHECK2(*cp, header_len + 1); /* length, flags */ - flags = cp[1]; + body_len_declared = GET_U_1(cp); + ND_PRINT(" frame flags+body (8-bit) length %" PRIu64, body_len_declared); } else { header_len = 1 + 8; /* 0xFF, length */ - printf(" frame flags+body (64-bit) length"); - TCHECK2(*cp, header_len); /* 0xFF, length */ - body_len_declared = EXTRACT_64BITS(cp + 1); - if (body_len_declared == 0) - return cp + header_len; /* skip to next frame */ - printf(" %" PRIu64, body_len_declared); - TCHECK2(*cp, header_len + 1); /* 0xFF, length, flags */ - flags = cp[9]; + ND_PRINT(" frame flags+body (64-bit) length"); + ND_TCHECK_LEN(cp, header_len); /* 0xFF, length */ + body_len_declared = GET_BE_U_8(cp + 1); + ND_PRINT(" %" PRIu64, body_len_declared); } + if (body_len_declared == 0) + return cp + header_len; /* skip to the next frame */ + ND_TCHECK_LEN(cp, header_len + 1); /* ..., flags */ + flags = GET_U_1(cp + header_len); body_len_captured = ep - cp - header_len; if (body_len_declared > body_len_captured) - printf(" (%" PRIu64 " captured)", body_len_captured); - printf(", flags 0x%02x", flags); - - if (vflag) { - u_int64_t body_len_printed = MIN(body_len_captured, body_len_declared); - - printf(" (%s|%s|%s|%s|%s|%s|%s|%s)", - flags & 0x80 ? "MBZ" : "-", - flags & 0x40 ? "MBZ" : "-", - flags & 0x20 ? "MBZ" : "-", - flags & 0x10 ? "MBZ" : "-", - flags & 0x08 ? "MBZ" : "-", - flags & 0x04 ? "MBZ" : "-", - flags & 0x02 ? "MBZ" : "-", - flags & 0x01 ? "MORE" : "-"); - - if (vflag == 1) - body_len_printed = MIN(VBYTES + 1, body_len_printed); + ND_PRINT(" (%" PRIu64 " captured)", body_len_captured); + ND_PRINT(", flags 0x%02x", flags); + + if (ndo->ndo_vflag) { + uint64_t body_len_printed = ND_MIN(body_len_captured, body_len_declared); + + ND_PRINT(" (%s)", bittok2str(flags_bm, "none", flags)); + if (ndo->ndo_vflag == 1) + body_len_printed = ND_MIN(VBYTES + 1, body_len_printed); if (body_len_printed > 1) { - printf(", first %" PRIu64 " byte(s) of body:", body_len_printed - 1); - hex_and_ascii_print("\n\t ", cp + header_len + 1, body_len_printed - 1); - printf("\n"); + ND_PRINT(", first %" PRIu64 " byte(s) of body:", body_len_printed - 1); + hex_and_ascii_print(ndo, "\n\t ", cp + header_len + 1, body_len_printed - 1); } } - TCHECK2(*cp, header_len + body_len_declared); /* Next frame within the buffer ? */ - return cp + header_len + body_len_declared; + /* + * Do not advance cp by the sum of header_len and body_len_declared + * before each offset has successfully passed ND_TCHECK_LEN() as the + * sum can roll over (9 + 0xfffffffffffffff7 = 0) and cause an + * infinite loop. + */ + cp += header_len; + ND_TCHECK_LEN(cp, body_len_declared); /* Next frame within the buffer ? */ + return cp + body_len_declared; trunc: - printf(" [|zmtp1]"); - return ep; + nd_trunc_longjmp(ndo); } void -zmtp1_print(const u_char *cp, u_int len) { - const u_char *ep = MIN(snapend, cp + len); +zmtp1_print(netdissect_options *ndo, const u_char *cp, u_int len) +{ + const u_char *ep = ND_MIN(ndo->ndo_snapend, cp + len); - printf(": ZMTP/1.0"); + ndo->ndo_protocol = "zmtp1"; + ND_PRINT(": ZMTP/1.0"); while (cp < ep) - cp = zmtp1_print_frame(cp, ep); + cp = zmtp1_print_frame(ndo, cp, ep); } +/* The functions below decode a ZeroMQ datagram, supposedly stored in the "Data" + * field of an ODATA/RDATA [E]PGM packet. An excerpt from zmq_pgm(7) man page + * follows. + * + * In order for late joining consumers to be able to identify message + * boundaries, each PGM datagram payload starts with a 16-bit unsigned integer + * in network byte order specifying either the offset of the first message frame + * in the datagram or containing the value 0xFFFF if the datagram contains + * solely an intermediate part of a larger message. + * + * Note that offset specifies where the first message begins rather than the + * first message part. Thus, if there are trailing message parts at the + * beginning of the packet the offset ignores them and points to first initial + * message part in the packet. + */ + +static const u_char * +zmtp1_print_intermediate_part(netdissect_options *ndo, const u_char *cp, const u_int len) +{ + u_int frame_offset; + u_int remaining_len; + + frame_offset = GET_BE_U_2(cp); + ND_PRINT("\n\t frame offset 0x%04x", frame_offset); + cp += 2; + remaining_len = ND_BYTES_AVAILABLE_AFTER(cp); /* without the frame length */ + + if (frame_offset == 0xFFFF) + frame_offset = len - 2; /* always within the declared length */ + else if (2 + frame_offset > len) { + ND_PRINT(" (exceeds datagram declared length)"); + goto trunc; + } + + /* offset within declared length of the datagram */ + if (frame_offset) { + ND_PRINT("\n\t frame intermediate part, %u bytes", frame_offset); + if (frame_offset > remaining_len) + ND_PRINT(" (%u captured)", remaining_len); + if (ndo->ndo_vflag) { + u_int len_printed = ND_MIN(frame_offset, remaining_len); + + if (ndo->ndo_vflag == 1) + len_printed = ND_MIN(VBYTES, len_printed); + if (len_printed > 1) { + ND_PRINT(", first %u byte(s):", len_printed); + hex_and_ascii_print(ndo, "\n\t ", cp, len_printed); + } + } + } + return cp + frame_offset; + +trunc: + nd_trunc_longjmp(ndo); +} + +void +zmtp1_datagram_print(netdissect_options *ndo, const u_char *cp, const u_int len) +{ + const u_char *ep = ND_MIN(ndo->ndo_snapend, cp + len); + + ndo->ndo_protocol = "zmtp1"; + cp = zmtp1_print_intermediate_part(ndo, cp, len); + while (cp < ep) + cp = zmtp1_print_frame(ndo, cp, ep); +}