diff options
| author | Denis Ovsienko <denis@ovsienko.info> | 2017-08-27 14:15:17 +0100 |
|---|---|---|
| committer | Denis Ovsienko <denis@ovsienko.info> | 2017-08-27 14:19:25 +0100 |
| commit | b3fb6a6c61e25ef8be56a2f1da7790a4e5ccd20b (patch) | |
| tree | 0ce06ef12a7abd269a88240027d1e22e56b0a673 /ipproto.c | |
| parent | 1b17a8cc5e2f73c17a11b07ada38e2cb173975a7 (diff) | |
| download | tcpdump-b3fb6a6c61e25ef8be56a2f1da7790a4e5ccd20b.tar.gz | |
Use a table instead of getprotobynumber().
On Linux getprotobynumber() returns different results for the same
argument depending on the contents of /etc/protocols at runtime
(expectedly but gets in the way of reproducible test cases). On FreeBSD
it returns results that are irrelevant of the contents of /etc/protocols
at runtime (unexpectedly). Other implementations exist and may expose
interesting properties too. And if the host uses LDAP instead of
/etc/protocols for name services, a call to that function may cause LDAP
handle the request. All of the above is not right for the specific task
of network protocols decoding, which needs to be fast and deterministic.
As the protocol number space is just 8-bit, add a 256-element array of
strings/NULLs for the translation and a wrapper function around it for
index range enforcement. Change the code to use the new function instead
of getprotobynumber().
Fix a typo while at it.
Diffstat (limited to 'ipproto.c')
| -rw-r--r-- | ipproto.c | 305 |
1 files changed, 305 insertions, 0 deletions
@@ -53,3 +53,308 @@ const struct tok ipproto_values[] = { { 0, NULL } }; +/* + * For completeness the number space in the array below comes from IANA: + * https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml + * However, the spelling tries to match that of /etc/protocols to achieve as + * much consistency as possible with the previously implemented behaviour, + * which was based on getprotobynumber (3). + */ +static const char *netdb_protocol_names[256] = { + "hopopt", /* 0 (IPPROTO_HOPOPTS, IPv6 Hop-by-Hop Option) */ + "icmp", /* 1 (IPPROTO_ICMP, Internet Control Message) */ + "igmp", /* 2 (IPPROTO_IGMP, Internet Group Management) */ + "ggp", /* 3 (Gateway-to-Gateway) */ + "ipencap", /* 4 (IPPROTO_IPV4, IPv4 encapsulation) */ + "st", /* 5 (Stream, ST datagram mode) */ + "tcp", /* 6 (IPPROTO_TCP, Transmission Control) */ + "cbt", /* 7 (CBT) */ + "egp", /* 8 (IPPROTO_EGP, Exterior Gateway Protocol) */ + "igp", /* 9 (IPPROTO_PIGP, "any private interior gateway + * (used by Cisco for their IGRP)") + */ + "bbn-rcc-mon", /* 10 (BBN RCC Monitoring) */ + "nvp-ii", /* 11 (Network Voice Protocol) */ + "pup", /* 12 (PARC universal packet protocol) */ + "argus", /* 13 (ARGUS) */ + "emcon", /* 14 (EMCON) */ + "xnet", /* 15 (Cross Net Debugger) */ + "chaos", /* 16 (Chaos) */ + "udp", /* 17 (IPPROTO_UDP, User Datagram) */ + "mux", /* 18 (Multiplexing) */ + "dcn-meas", /* 19 (DCN Measurement Subsystems) */ + "hmp", /* 20 (Host Monitoring) */ + "prm", /* 21 (Packet Radio Measurement) */ + "xns-idp", /* 22 (XEROX NS IDP) */ + "trunk-1", /* 23 (Trunk-1) */ + "trunk-2", /* 24 (Trunk-2) */ + "leaf-1", /* 25 (Leaf-1) */ + "leaf-2", /* 26 (Leaf-2) */ + "rdp", /* 27 (Reliable Data Protocol) */ + "irtp", /* 28 (Internet Reliable Transaction) */ + "iso-tp4", /* 29 (ISO Transport Protocol Class 4) */ + "netblt", /* 30 (Bulk Data Transfer Protocol) */ + "mfe-nsp", /* 31 (MFE Network Services Protocol) */ + "merit-inp", /* 32 (MERIT Internodal Protocol) */ + "dccp", /* 33 (IPPROTO_DCCP, Datagram Congestion + * Control Protocol) + */ + "3pc", /* 34 (Third Party Connect Protocol) */ + "idpr", /* 35 (Inter-Domain Policy Routing Protocol) */ + "xtp", /* 36 (Xpress Transfer Protocol) */ + "ddp", /* 37 (Datagram Delivery Protocol) */ + "idpr-cmtp", /* 38 (IDPR Control Message Transport Proto) */ + "tp++", /* 39 (TP++ Transport Protocol) */ + "il", /* 40 (IL Transport Protocol) */ + "ipv6", /* 41 (IPPROTO_IPV6, IPv6 encapsulation) */ + "sdrp", /* 42 (Source Demand Routing Protocol) */ + "ipv6-route", /* 43 (IPPROTO_ROUTING, Routing Header for IPv6) */ + "ipv6-frag", /* 44 (IPPROTO_FRAGMENT, Fragment Header for + * IPv6) + */ + "idrp", /* 45 (Inter-Domain Routing Protocol) */ + "rsvp", /* 46 (IPPROTO_RSVP, Reservation Protocol) */ + "gre", /* 47 (IPPROTO_GRE, Generic Routing + * Encapsulation) + */ + "dsr", /* 48 (Dynamic Source Routing Protocol) */ + "bna", /* 49 (BNA) */ + "esp", /* 50 (IPPROTO_ESP, Encap Security Payload) */ + "ah", /* 51 (IPPROTO_AH, Authentication Header) */ + "i-nlsp", /* 52 (Integrated Net Layer Security TUBA) */ + "swipe", /* 53 (IP with Encryption) */ + "narp", /* 54 (NBMA Address Resolution Protocol) */ + "mobile", /* 55 (IPPROTO_MOBILE, IP Mobility) */ + "tlsp", /* 56 (Transport Layer Security Protocol using + * Kryptonet key management) + */ + "skip", /* 57 (SKIP) */ + "ipv6-icmp", /* 58 (IPPROTO_ICMPV6, ICMP for IPv6) */ + "ipv6-nonxt", /* 59 (IPPROTO_NONE, No Next Header for IPv6) */ + "ipv6-opts", /* 60 (IPPROTO_DSTOPTS, Destination Options for + * IPv6) + */ + NULL, /* 61 (any host internal protocol) */ + "cftp", /* 62 (IPPROTO_MOBILITY_OLD, CFTP, see the note + * in ipproto.h) + */ + NULL, /* 63 (any local network) */ + "sat-expak", /* 64 (SATNET and Backroom EXPAK) */ + "kryptolan", /* 65 (Kryptolan) */ + "rvd", /* 66 (MIT Remote Virtual Disk Protocol) */ + "ippc", /* 67 (Internet Pluribus Packet Core) */ + NULL, /* 68 (any distributed file system) */ + "sat-mon", /* 69 (SATNET Monitoring) */ + "visa", /* 70 (VISA Protocol) */ + "ipcv", /* 71 (Internet Packet Core Utility) */ + "cpnx", /* 72 (Computer Protocol Network Executive) */ + "rspf", /* 73 (Radio Shortest Path First, CPHB -- Computer + * Protocol Heart Beat -- in IANA) + */ + "wsn", /* 74 (Wang Span Network) */ + "pvp", /* 75 (Packet Video Protocol) */ + "br-sat-mon", /* 76 (Backroom SATNET Monitoring) */ + "sun-nd", /* 77 (IPPROTO_ND, SUN ND PROTOCOL-Temporary) */ + "wb-mon", /* 78 (WIDEBAND Monitoring) */ + "wb-expak", /* 79 (WIDEBAND EXPAK) */ + "iso-ip", /* 80 (ISO Internet Protocol) */ + "vmtp", /* 81 (Versatile Message Transport) */ + "secure-vmtp", /* 82 (Secure VMTP) */ + "vines", /* 83 (VINES) */ + "ttp", /* 84 (Transaction Transport Protocol, also IPTM -- + * Internet Protocol Traffic Manager) + */ + "nsfnet-igp", /* 85 (NSFNET-IGP) */ + "dgp", /* 86 (Dissimilar Gateway Protocol) */ + "tcf", /* 87 (TCF) */ + "eigrp", /* 88 (IPPROTO_EIGRP, Cisco EIGRP) */ + "ospf", /* 89 (IPPROTO_OSPF, Open Shortest Path First + * IGP) + */ + "sprite-rpc", /* 90 (Sprite RPC Protocol) */ + "larp", /* 91 (Locus Address Resolution Protocol) */ + "mtp", /* 92 (Multicast Transport Protocol) */ + "ax.25", /* 93 (AX.25 Frames) */ + "ipip", /* 94 (IP-within-IP Encapsulation Protocol) */ + "micp", /* 95 (Mobile Internetworking Control Pro.) */ + "scc-sp", /* 96 (Semaphore Communications Sec. Pro.) */ + "etherip", /* 97 (Ethernet-within-IP Encapsulation) */ + "encap", /* 98 (Encapsulation Header) */ + NULL, /* 99 (any private encryption scheme) */ + "gmtp", /* 100 (GMTP) */ + "ifmp", /* 101 (Ipsilon Flow Management Protocol) */ + "pnni", /* 102 (PNNI over IP) */ + "pim", /* 103 (IPPROTO_PIM, Protocol Independent + * Multicast) + */ + "aris", /* 104 (ARIS) */ + "scps", /* 105 (SCPS) */ + "qnx", /* 106 (QNX) */ + "a/n", /* 107 (Active Networks) */ + "ipcomp", /* 108 (IPPROTO_IPCOMP, IP Payload Compression + * Protocol) + */ + "snp", /* 109 (Sitara Networks Protocol) */ + "compaq-peer", /* 110 (Compaq Peer Protocol) */ + "ipx-in-ip", /* 111 (IPX in IP) */ + "vrrp", /* 112 (IPPROTO_VRRP, Virtual Router Redundancy + * Protocol) + */ + "pgm", /* 113 (IPPROTO_PGM, PGM Reliable Transport + * Protocol) + */ + NULL, /* 114 (any 0-hop protocol) */ + "l2tp", /* 115 (Layer Two Tunneling Protocol) */ + "ddx", /* 116 (D-II Data Exchange (DDX)) */ + "iatp", /* 117 (Interactive Agent Transfer Protocol) */ + "stp", /* 118 (Schedule Transfer Protocol) */ + "srp", /* 119 (SpectraLink Radio Protocol) */ + "uti", /* 120 (UTI) */ + "smp", /* 121 (Simple Message Protocol) */ + "sm", /* 122 (Simple Multicast Protocol) */ + "ptp", /* 123 (Performance Transparency Protocol) */ + "isis", /* 124 (ISIS over IPv4) */ + "fire", /* 125 (FIRE) */ + "crtp", /* 126 (Combat Radio Transport Protocol) */ + "crudp", /* 127 (Combat Radio User Datagram) */ + "sscopmce", /* 128 (SSCOPMCE) */ + "iplt", /* 129 (IPLT) */ + "sps", /* 130 (Secure Packet Shield) */ + "pipe", /* 131 (Private IP Encapsulation within IP) */ + "sctp", /* 132 (IPPROTO_SCTP, Stream Control Transmission + * Protocol) + */ + "fc", /* 133 (Fibre Channel) */ + "rsvp-e2e-ignore", /* 134 (RSVP-E2E-IGNORE) */ + "mobility-header", /* 135 (IPPROTO_MOBILITY, Mobility Header) */ + "udplite", /* 136 (UDPLite) */ + "mpls-in-ip", /* 137 (MPLS-in-IP) */ + "manet", /* 138 (MANET Protocols) */ + "hip", /* 139 (Host Identity Protocol) */ + "shim6", /* 140 (Shim6 Protocol) */ + "wesp", /* 141 (Wrapped Encapsulating Security Payload) */ + "rohc", /* 142 (Robust Header Compression) */ + NULL, /* 143 (unassigned) */ + NULL, /* 144 (unassigned) */ + NULL, /* 145 (unassigned) */ + NULL, /* 146 (unassigned) */ + NULL, /* 147 (unassigned) */ + NULL, /* 148 (unassigned) */ + NULL, /* 149 (unassigned) */ + NULL, /* 150 (unassigned) */ + NULL, /* 151 (unassigned) */ + NULL, /* 152 (unassigned) */ + NULL, /* 153 (unassigned) */ + NULL, /* 154 (unassigned) */ + NULL, /* 155 (unassigned) */ + NULL, /* 156 (unassigned) */ + NULL, /* 157 (unassigned) */ + NULL, /* 158 (unassigned) */ + NULL, /* 159 (unassigned) */ + NULL, /* 160 (unassigned) */ + NULL, /* 161 (unassigned) */ + NULL, /* 162 (unassigned) */ + NULL, /* 163 (unassigned) */ + NULL, /* 164 (unassigned) */ + NULL, /* 165 (unassigned) */ + NULL, /* 166 (unassigned) */ + NULL, /* 167 (unassigned) */ + NULL, /* 168 (unassigned) */ + NULL, /* 169 (unassigned) */ + NULL, /* 170 (unassigned) */ + NULL, /* 171 (unassigned) */ + NULL, /* 172 (unassigned) */ + NULL, /* 173 (unassigned) */ + NULL, /* 174 (unassigned) */ + NULL, /* 175 (unassigned) */ + NULL, /* 176 (unassigned) */ + NULL, /* 177 (unassigned) */ + NULL, /* 178 (unassigned) */ + NULL, /* 179 (unassigned) */ + NULL, /* 180 (unassigned) */ + NULL, /* 181 (unassigned) */ + NULL, /* 182 (unassigned) */ + NULL, /* 183 (unassigned) */ + NULL, /* 184 (unassigned) */ + NULL, /* 185 (unassigned) */ + NULL, /* 186 (unassigned) */ + NULL, /* 187 (unassigned) */ + NULL, /* 188 (unassigned) */ + NULL, /* 189 (unassigned) */ + NULL, /* 190 (unassigned) */ + NULL, /* 191 (unassigned) */ + NULL, /* 192 (unassigned) */ + NULL, /* 193 (unassigned) */ + NULL, /* 194 (unassigned) */ + NULL, /* 195 (unassigned) */ + NULL, /* 196 (unassigned) */ + NULL, /* 197 (unassigned) */ + NULL, /* 198 (unassigned) */ + NULL, /* 199 (unassigned) */ + NULL, /* 200 (unassigned) */ + NULL, /* 201 (unassigned) */ + NULL, /* 202 (unassigned) */ + NULL, /* 203 (unassigned) */ + NULL, /* 204 (unassigned) */ + NULL, /* 205 (unassigned) */ + NULL, /* 206 (unassigned) */ + NULL, /* 207 (unassigned) */ + NULL, /* 208 (unassigned) */ + NULL, /* 209 (unassigned) */ + NULL, /* 210 (unassigned) */ + NULL, /* 211 (unassigned) */ + NULL, /* 212 (unassigned) */ + NULL, /* 213 (unassigned) */ + NULL, /* 214 (unassigned) */ + NULL, /* 215 (unassigned) */ + NULL, /* 216 (unassigned) */ + NULL, /* 217 (unassigned) */ + NULL, /* 218 (unassigned) */ + NULL, /* 219 (unassigned) */ + NULL, /* 220 (unassigned) */ + NULL, /* 221 (unassigned) */ + NULL, /* 222 (unassigned) */ + NULL, /* 223 (unassigned) */ + NULL, /* 224 (unassigned) */ + NULL, /* 225 (unassigned) */ + NULL, /* 226 (unassigned) */ + NULL, /* 227 (unassigned) */ + NULL, /* 228 (unassigned) */ + NULL, /* 229 (unassigned) */ + NULL, /* 230 (unassigned) */ + NULL, /* 231 (unassigned) */ + NULL, /* 232 (unassigned) */ + NULL, /* 233 (unassigned) */ + NULL, /* 234 (unassigned) */ + NULL, /* 235 (unassigned) */ + NULL, /* 236 (unassigned) */ + NULL, /* 237 (unassigned) */ + NULL, /* 238 (unassigned) */ + NULL, /* 239 (unassigned) */ + NULL, /* 240 (unassigned) */ + NULL, /* 241 (unassigned) */ + NULL, /* 242 (unassigned) */ + NULL, /* 243 (unassigned) */ + NULL, /* 244 (unassigned) */ + NULL, /* 245 (unassigned) */ + NULL, /* 246 (unassigned) */ + NULL, /* 247 (unassigned) */ + NULL, /* 248 (unassigned) */ + NULL, /* 249 (unassigned) */ + NULL, /* 250 (unassigned) */ + NULL, /* 251 (unassigned) */ + "exptest-253", /* 253 (Use for experimentation and testing, + * RFC 3692) + */ + "exptest-254", /* 254 (Use for experimentation and testing, + * RFC 3692) + */ + "reserved", /* 255 (reserved) */ +}; + +/* The function enforces the array index to be 8-bit. */ +const char * +netdb_protoname (const nd_uint8_t protoid) +{ + return netdb_protocol_names[protoid]; +} |