X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ed85e20e4d6a27d5405f37366dd34b64c10a9211..c7b0738460b08e63a1bd15c88ef1f9599cd71a08:/print-mptcp.c diff --git a/print-mptcp.c b/print-mptcp.c index f85f1d24..392791e6 100644 --- a/print-mptcp.c +++ b/print-mptcp.c @@ -32,14 +32,17 @@ * SUCH DAMAGE. */ -#define NETDISSECT_REWORKED +/* \summary: Multipath TCP (MPTCP) printer */ + +/* specification: RFC 6824 */ + #ifdef HAVE_CONFIG_H #include "config.h" #endif -#include +#include -#include "interface.h" +#include "netdissect.h" #include "extract.h" #include "addrtoname.h" @@ -173,9 +176,9 @@ static int mp_capable_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags) { - struct mp_capable *mpc = (struct mp_capable *) opt; + const struct mp_capable *mpc = (const struct mp_capable *) opt; - if (!(opt_len == 12 && flags & TH_SYN) && + if (!(opt_len == 12 && (flags & TH_SYN)) && !(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK)) return 0; @@ -197,11 +200,11 @@ static int mp_join_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags) { - struct mp_join *mpj = (struct mp_join *) opt; + const struct mp_join *mpj = (const struct mp_join *) opt; - if (!(opt_len == 12 && flags & TH_SYN) && + if (!(opt_len == 12 && (flags & TH_SYN)) && !(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) && - !(opt_len == 24 && flags & TH_ACK)) + !(opt_len == 24 && (flags & TH_ACK))) return 0; if (opt_len != 24) { @@ -233,76 +236,92 @@ mp_join_print(netdissect_options *ndo, return 1; } -static u_int mp_dss_len(struct mp_dss *m, int csum) -{ - u_int len; - - len = 4; - if (m->flags & MP_DSS_A) { - /* Ack present - 4 or 8 octets */ - len += (m->flags & MP_DSS_a) ? 8 : 4; - } - if (m->flags & MP_DSS_M) { - /* - * Data Sequence Number (DSN), Subflow Sequence Number (SSN), - * Data-Level Length present, and Checksum possibly present. - * All but the Checksum are 10 bytes if the m flag is - * clear (4-byte DSN) and 14 bytes if the m flag is set - * (8-byte DSN). - */ - len += (m->flags & MP_DSS_m) ? 14 : 10; - - /* - * The Checksum is present only if negotiated. - */ - if (csum) - len += 2; - } - return len; -} - static int mp_dss_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags) { - struct mp_dss *mdss = (struct mp_dss *) opt; + const struct mp_dss *mdss = (const struct mp_dss *) opt; - if ((opt_len != mp_dss_len(mdss, 1) && - opt_len != mp_dss_len(mdss, 0)) || flags & TH_SYN) + /* We need the flags, at a minimum. */ + if (opt_len < 4) + return 0; + + if (flags & TH_SYN) return 0; if (mdss->flags & MP_DSS_F) ND_PRINT((ndo, " fin")); opt += 4; + opt_len -= 4; if (mdss->flags & MP_DSS_A) { + /* Ack present */ ND_PRINT((ndo, " ack ")); + /* + * If the a flag is set, we have an 8-byte ack; if it's + * clear, we have a 4-byte ack. + */ if (mdss->flags & MP_DSS_a) { + if (opt_len < 8) + return 0; ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt))); opt += 8; + opt_len -= 8; } else { + if (opt_len < 4) + return 0; ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt))); opt += 4; + opt_len -= 4; } } if (mdss->flags & MP_DSS_M) { + /* + * Data Sequence Number (DSN), Subflow Sequence Number (SSN), + * Data-Level Length present, and Checksum possibly present. + */ ND_PRINT((ndo, " seq ")); + /* + * If the m flag is set, we have an 8-byte NDS; if it's clear, + * we have a 4-byte DSN. + */ if (mdss->flags & MP_DSS_m) { + if (opt_len < 8) + return 0; ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt))); opt += 8; + opt_len -= 8; } else { + if (opt_len < 4) + return 0; ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt))); opt += 4; + opt_len -= 4; } + if (opt_len < 4) + return 0; ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt))); opt += 4; + opt_len -= 4; + if (opt_len < 2) + return 0; ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt))); opt += 2; + opt_len -= 2; - if (opt_len == mp_dss_len(mdss, 1)) + /* + * The Checksum is present only if negotiated. + * If there are at least 2 bytes left, process the next 2 + * bytes as the Checksum. + */ + if (opt_len >= 2) { ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt))); + opt_len -= 2; + } } + if (opt_len != 0) + return 0; return 1; } @@ -310,7 +329,7 @@ static int add_addr_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags _U_) { - struct mp_add_addr *add_addr = (struct mp_add_addr *) opt; + const struct mp_add_addr *add_addr = (const struct mp_add_addr *) opt; u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver); if (!((opt_len == 8 || opt_len == 10) && ipver == 4) && @@ -325,9 +344,7 @@ add_addr_print(netdissect_options *ndo, ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v4.port))); break; case 6: -#ifdef INET6 ND_PRINT((ndo, " %s", ip6addr_string(ndo, add_addr->u.v6.addr))); -#endif if (opt_len == 22) ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v6.port))); break; @@ -342,8 +359,8 @@ static int remove_addr_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags _U_) { - struct mp_remove_addr *remove_addr = (struct mp_remove_addr *) opt; - uint8_t *addr_id = &remove_addr->addrs_id; + const struct mp_remove_addr *remove_addr = (const struct mp_remove_addr *) opt; + const uint8_t *addr_id = &remove_addr->addrs_id; if (opt_len < 4) return 0; @@ -359,7 +376,7 @@ static int mp_prio_print(netdissect_options *ndo, const u_char *opt, u_int opt_len, u_char flags _U_) { - struct mp_prio *mpp = (struct mp_prio *) opt; + const struct mp_prio *mpp = (const struct mp_prio *) opt; if (opt_len != 3 && opt_len != 4) return 0; @@ -415,13 +432,13 @@ int mptcp_print(netdissect_options *ndo, const u_char *cp, u_int len, u_char flags) { - struct mptcp_option *opt; + const struct mptcp_option *opt; u_int subtype; if (len < 3) return 0; - opt = (struct mptcp_option *) cp; + opt = (const struct mptcp_option *) cp; subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1); ND_PRINT((ndo, " %s", mptcp_options[subtype].name));