struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk, gfp_t gfp, int unkparam_len) { sctp_inithdr_t initack; struct sctp_chunk *retval; union sctp_params addrs; struct sctp_sock *sp; int addrs_len; sctp_cookie_param_t *cookie; int cookie_len; size_t chunksize; sctp_adaptation_ind_param_t aiparam; sctp_supported_ext_param_t ext_param; int num_ext = 0; __u8 extensions[3]; sctp_paramhdr_t *auth_chunks = NULL, *auth_hmacs = NULL, *auth_random = NULL; retval = NULL; /* Note: there may be no addresses to embed. */ addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); initack.init_tag = htonl(asoc->c.my_vtag); initack.a_rwnd = htonl(asoc->rwnd); initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); initack.initial_tsn = htonl(asoc->c.initial_tsn); /* FIXME: We really ought to build the cookie right * into the packet instead of allocating more fresh memory. */ cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, addrs.v, addrs_len); if (!cookie) goto nomem_cookie; /* Calculate the total size of allocation, include the reserved * space for reporting unknown parameters if it is specified. */ sp = sctp_sk(asoc->base.sk); chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; /* Tell peer that we'll do ECN
struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, const struct sctp_chunk *chunk, gfp_t gfp, int unkparam_len) { sctp_inithdr_t initack; struct sctp_chunk *retval; union sctp_params addrs; struct sctp_sock *sp; int addrs_len; sctp_cookie_param_t *cookie; int cookie_len; size_t chunksize; sctp_adaptation_ind_param_t aiparam; sctp_supported_ext_param_t ext_param; int num_ext = 0; __u8 extensions[3]; sctp_paramhdr_t *auth_chunks = NULL, *auth_hmacs = NULL, *auth_random = NULL; retval = NULL; /* Note: there may be no addresses to embed. */ addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); initack.init_tag = htonl(asoc->c.my_vtag); initack.a_rwnd = htonl(asoc->rwnd); initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); initack.initial_tsn = htonl(asoc->c.initial_tsn); /* FIXME: We really ought to build the cookie right * into the packet instead of allocating more fresh memory. */ cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, addrs.v, addrs_len); if (!cookie) goto nomem_cookie; /* Calculate the total size of allocation, include the reserved * space for reporting unknown parameters if it is specified. */ sp = sctp_sk(asoc->base.sk); chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; /* Tell peer that we'll do ECN only if peer advertised such cap. */ if (asoc->peer.ecn_capable) chunksize += sizeof(ecap_param); if (asoc->peer.prsctp_capable) chunksize += sizeof(prsctp_param); if (asoc->peer.asconf_capable) { extensions[num_ext] = SCTP_CID_ASCONF; extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; num_ext += 2; } if (sp->adaptation_ind) chunksize += sizeof(aiparam); if (asoc->peer.auth_capable) { auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; chunksize += ntohs(auth_random->length); auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; if (auth_hmacs->length) chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); else auth_hmacs = NULL; auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; if (auth_chunks->length) chunksize += WORD_ROUND(ntohs(auth_chunks->length)); else auth_chunks = NULL; extensions[num_ext] = SCTP_CID_AUTH; num_ext += 1; } if (num_ext) chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + num_ext); /* Now allocate and fill out the chunk. */ retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize); if (!retval) goto nomem_chunk; /* RFC 2960 6.4 Multi-homed SCTP Endpoints * * An endpoint SHOULD transmit reply chunks (e.g., SACK, * HEARTBEAT ACK, * etc.) to the same destination transport * address from which it received the DATA or control chunk * to which it is replying. * * [INIT ACK back to where the INIT came from.] */ retval->transport = chunk->transport; retval->subh.init_hdr = sctp_addto_chunk(retval, sizeof(initack), &initack); retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); sctp_addto_chunk(retval, cookie_len, cookie); if (asoc->peer.ecn_capable) sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); if (num_ext) { ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; ext_param.param_hdr.length = htons(sizeof(sctp_supported_ext_param_t) + num_ext); sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), &ext_param); sctp_addto_param(retval, num_ext, extensions); } if (asoc->peer.prsctp_capable) sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); if (sp->adaptation_ind) { aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; aiparam.param_hdr.length = htons(sizeof(aiparam)); aiparam.adaptation_ind = htonl(sp->adaptation_ind); sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); } if (asoc->peer.auth_capable) { sctp_addto_chunk(retval, ntohs(auth_random->length), auth_random); if (auth_hmacs) sctp_addto_chunk(retval, ntohs(auth_hmacs->length), auth_hmacs); if (auth_chunks) sctp_addto_chunk(retval, ntohs(auth_chunks->length), auth_chunks); } /* We need to remove the const qualifier at this point. */ retval->asoc = (struct sctp_association *) asoc; nomem_chunk: kfree(cookie); nomem_cookie: kfree(addrs.v); return retval; }