X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/56bcff3da9fa58a9b3f8132d71a2fd9497ef799e..0845bc813c1cc48b18cdefff0b387c110647463c:/print-zeromq.c diff --git a/print-zeromq.c b/print-zeromq.c index 10ca2cc4..410241e4 100644 --- a/print-zeromq.c +++ b/print-zeromq.c @@ -34,11 +34,11 @@ #include -#include - -#include "interface.h" +#include "netdissect.h" #include "extract.h" +static const char tstr[] = " [|zmtp1]"; + /* 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 +75,43 @@ */ 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((ndo, "\n\t")); + ND_TCHECK2(*cp, 1); /* length/0xFF */ if (cp[0] != 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 */ + ND_PRINT((ndo, " frame flags+body (8-bit) length %u", cp[0])); + ND_TCHECK2(*cp, header_len + 1); /* length, flags */ flags = cp[1]; } else { header_len = 1 + 8; /* 0xFF, length */ - printf(" frame flags+body (64-bit) length"); - TCHECK2(*cp, header_len); /* 0xFF, length */ + ND_PRINT((ndo, " frame flags+body (64-bit) length")); + ND_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 */ + ND_PRINT((ndo, " %" PRIu64, body_len_declared)); + ND_TCHECK2(*cp, header_len + 1); /* 0xFF, length, flags */ flags = cp[9]; } 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); + ND_PRINT((ndo, " (%" PRIu64 " captured)", body_len_captured)); + ND_PRINT((ndo, ", 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((ndo, " (%s|%s|%s|%s|%s|%s|%s|%s)", flags & 0x80 ? "MBZ" : "-", flags & 0x40 ? "MBZ" : "-", flags & 0x20 ? "MBZ" : "-", @@ -118,31 +119,100 @@ zmtp1_print_frame(const u_char *cp, const u_char *ep) { flags & 0x08 ? "MBZ" : "-", flags & 0x04 ? "MBZ" : "-", flags & 0x02 ? "MBZ" : "-", - flags & 0x01 ? "MORE" : "-"); + 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((ndo, ", 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((ndo, "\n")); } } - TCHECK2(*cp, header_len + body_len_declared); /* Next frame within the buffer ? */ + ND_TCHECK2(*cp, header_len + body_len_declared); /* Next frame within the buffer ? */ return cp + header_len + body_len_declared; trunc: - printf(" [|zmtp1]"); + ND_PRINT((ndo, "%s", tstr)); 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"); + ND_PRINT((ndo, ": 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_TCHECK2(*cp, 2); + frame_offset = EXTRACT_16BITS(cp); + ND_PRINT((ndo, "\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((ndo, " (exceeds datagram declared length)")); + goto trunc; + } + + /* offset within declared length of the datagram */ + if (frame_offset) { + ND_PRINT((ndo, "\n\t frame intermediate part, %u bytes", frame_offset)); + if (frame_offset > remaining_len) + ND_PRINT((ndo, " (%"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((ndo, ", first %"PRIu64" byte(s):", len_printed)); + hex_and_ascii_print(ndo, "\n\t ", cp, len_printed); + ND_PRINT((ndo, "\n")); + } + } + } + return cp + frame_offset; + +trunc: + ND_PRINT((ndo, "%s", tstr)); + return cp + len; +} + +void +zmtp1_print_datagram(netdissect_options *ndo, const u_char *cp, const u_int len) +{ + const u_char *ep = min(ndo->ndo_snapend, cp + len); + + cp = zmtp1_print_intermediate_part(ndo, cp, len); + while (cp < ep) + cp = zmtp1_print_frame(ndo, cp, ep); +}