X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/d84a8dfca144f096a10ffbd3047455ffcb712bfd..a8abce5c5e2dce2ba6dbccd5d3829da104b80f9c:/print-zeromq.c diff --git a/print-zeromq.c b/print-zeromq.c index d5ac4bd3..6e5e9dc8 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. * @@ -28,17 +25,18 @@ * POSSIBILITY OF SUCH DAMAGE. */ +/* \summary: ZeroMQ Message Transport Protocol (ZMTP) printer */ + #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include +#include "netdissect-stdinc.h" -#include - -#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. */ @@ -75,42 +73,39 @@ */ 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"); + ND_TCHECK_1(cp); /* length/0xFF */ - if (cp[0] != 0xFF) { + if (EXTRACT_U_1(cp) != 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 %"PRIu8"", cp[0]); - TCHECK2(*cp, header_len + 1); /* length, flags */ - flags = cp[1]; + body_len_declared = EXTRACT_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 = EXTRACT_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 = EXTRACT_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%02"PRIx8"", flags); + ND_PRINT(" (%" PRIu64 " captured)", body_len_captured); + ND_PRINT(", flags 0x%02x", flags); - if (vflag) { - u_int64_t body_len_printed = MIN(body_len_captured, body_len_declared); + if (ndo->ndo_vflag) { + uint64_t body_len_printed = min(body_len_captured, body_len_declared); - printf(" (%s|%s|%s|%s|%s|%s|%s|%s)", + ND_PRINT(" (%s|%s|%s|%s|%s|%s|%s|%s)", flags & 0x80 ? "MBZ" : "-", flags & 0x40 ? "MBZ" : "-", flags & 0x20 ? "MBZ" : "-", @@ -120,29 +115,107 @@ zmtp1_print_frame(const u_char *cp, const u_char *ep) { flags & 0x02 ? "MBZ" : "-", flags & 0x01 ? "MORE" : "-"); - if (vflag == 1) - body_len_printed = MIN(VBYTES + 1, body_len_printed); + if (ndo->ndo_vflag == 1) + body_len_printed = 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); + ND_PRINT("\n"); } } - 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]"); + nd_print_trunc(ndo); return ep; } 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 = 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; + uint64_t remaining_len; + + ND_TCHECK_2(cp); + frame_offset = EXTRACT_BE_U_2(cp); + ND_PRINT("\n\t frame offset 0x%04x", frame_offset); + cp += 2; + remaining_len = ndo->ndo_snapend - 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(" (%"PRIu64" captured)", remaining_len); + if (ndo->ndo_vflag) { + uint64_t len_printed = min(frame_offset, remaining_len); + + if (ndo->ndo_vflag == 1) + len_printed = min(VBYTES, len_printed); + if (len_printed > 1) { + ND_PRINT(", first %"PRIu64" byte(s):", len_printed); + hex_and_ascii_print(ndo, "\n\t ", cp, len_printed); + ND_PRINT("\n"); + } + } + } + return cp + frame_offset; + +trunc: + nd_print_trunc(ndo); + return cp + len; } +void +zmtp1_datagram_print(netdissect_options *ndo, const u_char *cp, const u_int len) +{ + const u_char *ep = 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); +}