/* * QEMU Bluetooth L2CAP logic. * * Copyright (C) 2008 Andrzej Zaborowski <balrog@zabor.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "qemu-common.h" #include "qemu-timer.h" #include "bt.h" #define L2CAP_CID_MAX 0x100 /* Between 0x40 and 0x10000 */ struct l2cap_instance_s { struct bt_link_s *link; struct bt_l2cap_device_s *dev; int role; uint8_t frame_in[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4))); int frame_in_len; uint8_t frame_out[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4))); int frame_out_len; /* Signalling channel timers. They exist per-request but we can make * sure we have no more than one outstanding request at any time. */ QEMUTimer *rtx; QEMUTimer *ertx; int last_id; int next_id; struct l2cap_chan_s { struct bt_l2cap_conn_params_s params; void (*frame_in)(struct l2cap_chan_s *chan, uint16_t cid, const l2cap_hdr *hdr, int len); int mps; int min_mtu; struct l2cap_instance_s *l2cap; /* Only allocated channels */ uint16_t remote_cid; #define L2CAP_CFG_INIT 2 #define L2CAP_CFG_ACC 1 int config_req_id; /* TODO: handle outgoing requests generically */ int config; /* Only connection-oriented channels. Note: if we allow the tx and * rx traffic to be in different modes at any time, we need two. */ int mode; /* Only flow-controlled, connection-oriented channels */ uint8_t sdu[65536]; /* TODO: dynamically allocate */ int len_cur, len_total; int rexmit; int monitor_timeout; QEMUTimer *monitor_timer; QEMUTimer *retransmission_timer; } *cid[L2CAP_CID_MAX]; /* The channel state machine states map as following: * CLOSED -> !cid[N] * WAIT_CONNECT -> never occurs * WAIT_CONNECT_RSP -> never occurs * CONFIG -> cid[N] && config < 3 * WAIT_CONFIG -> never occurs, cid[N] && config == 0 && !config_r * WAIT_SEND_CONFIG -> never occurs, cid[N] && config == 1 && !config_r * WAIT_CONFIG_REQ_RSP -> cid[N] && config == 0 && config_req_id * WAIT_CONFIG_RSP -> cid[N] && config == 1 && config_req_id * WAIT_CONFIG_REQ -> cid[N] && config == 2 * OPEN -> cid[N] && config == 3 * WAIT_DISCONNECT -> never occurs */ struct l2cap_chan_s signalling_ch; struct l2cap_chan_s group_ch; }; struct slave_l2cap_instance_s { struct bt_link_s link; /* Underlying logical link (ACL) */ struct l2cap_instance_s l2cap; }; struct bt_l2cap_psm_s { int psm; int min_mtu; int (*new_channel)(struct bt_l2cap_device_s *device, struct bt_l2cap_conn_params_s *params); struct bt_l2cap_psm_s *next; }; static const uint16_t l2cap_fcs16_table[256] = { 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, }; static uint16_t l2cap_fcs16(const uint8_t *message, int len) { uint16_t fcs = 0x0000; while (len --) #if 0 { int i; fcs ^= *message ++; for (i = 8; i; -- i) if (fcs & 1) fcs = (fcs >> 1) ^ 0xa001; else fcs = (fcs >> 1); } #else fcs = (fcs >> 8) ^ l2cap_fcs16_table[(fcs ^ *message ++) & 0xff]; #endif return fcs; } /* L2CAP layer logic (protocol) */ static void l2cap_retransmission_timer_update(struct l2cap_chan_s *ch) { #if 0 if (ch->mode != L2CAP_MODE_BASIC && ch->rexmit) qemu_mod_timer(ch->retransmission_timer); else qemu_del_timer(ch->retransmission_timer); #endif } static void l2cap_monitor_timer_update(struct l2cap_chan_s *ch) { #if 0 if (ch->mode != L2CAP_MODE_BASIC && !ch->rexmit) qemu_mod_timer(ch->monitor_timer); else qemu_del_timer(ch->monitor_timer); #endif } static void l2cap_command_reject(struct l2cap_instance_s *l2cap, int id, uint16_t reason, const void *data, int plen) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_cmd_rej *params; uint16_t len; reason = cpu_to_le16(reason); len = cpu_to_le16(L2CAP_CMD_REJ_SIZE + plen); pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_CMD_REJ_SIZE + plen); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_COMMAND_REJ; hdr->ident = id; memcpy(&hdr->len, &len, sizeof(hdr->len)); memcpy(¶ms->reason, &reason, sizeof(reason)); if (plen) memcpy(pkt + L2CAP_CMD_HDR_SIZE + L2CAP_CMD_REJ_SIZE, data, plen); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_command_reject_cid(struct l2cap_instance_s *l2cap, int id, uint16_t reason, uint16_t dcid, uint16_t scid) { l2cap_cmd_rej_cid params = { .dcid = dcid, .scid = scid, }; l2cap_command_reject(l2cap, id, reason, ¶ms, L2CAP_CMD_REJ_CID_SIZE); } static void l2cap_connection_response(struct l2cap_instance_s *l2cap, int dcid, int scid, int result, int status) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_conn_rsp *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_CONN_RSP_SIZE); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_CONN_RSP; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(L2CAP_CONN_RSP_SIZE); params->dcid = cpu_to_le16(dcid); params->scid = cpu_to_le16(scid); params->result = cpu_to_le16(result); params->status = cpu_to_le16(status); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_configuration_request(struct l2cap_instance_s *l2cap, int dcid, int flag, const uint8_t *data, int len) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_conf_req *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_CONF_REQ_SIZE(len)); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); /* TODO: unify the id sequencing */ l2cap->last_id = l2cap->next_id; l2cap->next_id = l2cap->next_id == 255 ? 1 : l2cap->next_id + 1; hdr->code = L2CAP_CONF_REQ; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(L2CAP_CONF_REQ_SIZE(len)); params->dcid = cpu_to_le16(dcid); params->flags = cpu_to_le16(flag); if (len) memcpy(params->data, data, len); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_configuration_response(struct l2cap_instance_s *l2cap, int scid, int flag, int result, const uint8_t *data, int len) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_conf_rsp *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_CONF_RSP_SIZE(len)); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_CONF_RSP; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(L2CAP_CONF_RSP_SIZE(len)); params->scid = cpu_to_le16(scid); params->flags = cpu_to_le16(flag); params->result = cpu_to_le16(result); if (len) memcpy(params->data, data, len); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_disconnection_response(struct l2cap_instance_s *l2cap, int dcid, int scid) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_disconn_rsp *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_DISCONN_RSP_SIZE); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_DISCONN_RSP; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(L2CAP_DISCONN_RSP_SIZE); params->dcid = cpu_to_le16(dcid); params->scid = cpu_to_le16(scid); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_echo_response(struct l2cap_instance_s *l2cap, const uint8_t *data, int len) { uint8_t *pkt; l2cap_cmd_hdr *hdr; uint8_t *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + len); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_ECHO_RSP; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(len); memcpy(params, data, len); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static void l2cap_info_response(struct l2cap_instance_s *l2cap, int type, int result, const uint8_t *data, int len) { uint8_t *pkt; l2cap_cmd_hdr *hdr; l2cap_info_rsp *params; pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params, L2CAP_CMD_HDR_SIZE + L2CAP_INFO_RSP_SIZE + len); hdr = (void *) (pkt + 0); params = (void *) (pkt + L2CAP_CMD_HDR_SIZE); hdr->code = L2CAP_INFO_RSP; hdr->ident = l2cap->last_id; hdr->len = cpu_to_le16(L2CAP_INFO_RSP_SIZE + len); params->type = cpu_to_le16(type); params->result = cpu_to_le16(result); if (len) memcpy(params->data, data, len); l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params); } static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len); static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms); #if 0 static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len); static void l2cap_iframe_submit(struct bt_l2cap_conn_params_s *parm); #endif static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid, const l2cap_hdr *hdr, int len); static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid, const l2cap_hdr *hdr, int len); static int l2cap_cid_new(struct l2cap_instance_s *l2cap) { int i; for (i = L2CAP_CID_ALLOC; i < L2CAP_CID_MAX; i ++) if (!l2cap->cid[i]) return i; return L2CAP_CID_INVALID; } static inline struct bt_l2cap_psm_s *l2cap_psm( struct bt_l2cap_device_s *device, int psm) { struct bt_l2cap_psm_s *ret = device->first_psm; while (ret && ret->psm != psm) ret = ret->next; return ret; } static struct l2cap_chan_s *l2cap_channel_open(struct l2cap_instance_s *l2cap, int psm, int source_cid) { struct l2cap_chan_s *ch = NULL; struct bt_l2cap_psm_s *psm_info; int result, status; int cid = l2cap_cid_new(l2cap); if (cid) { /* See what the channel is to be used for.. */ psm_info = l2cap_psm(l2cap->dev, psm); if (psm_info) { /* Device supports this use-case. */ ch = g_malloc0(sizeof(*ch)); ch->params.sdu_out = l2cap_bframe_out; ch->params.sdu_submit = l2cap_bframe_submit; ch->frame_in = l2cap_bframe_in; ch->mps = 65536; ch->min_mtu = MAX(48, psm_info->min_mtu); ch->params.remote_mtu = MAX(672, ch->min_mtu); ch->remote_cid = source_cid; ch->mode = L2CAP_MODE_BASIC; ch->l2cap = l2cap; /* Does it feel like opening yet another channel though? */ if (!psm_info->new_channel(l2cap->dev, &ch->params)) { l2cap->cid[cid] = ch; result = L2CAP_CR_SUCCESS; status = L2CAP_CS_NO_INFO; } else { g_free(ch); result = L2CAP_CR_NO_MEM; status = L2CAP_CS_NO_INFO; } } else { result = L2CAP_CR_BAD_PSM; status = L2CAP_CS_NO_INFO; } } else { result = L2CAP_CR_NO_MEM; status = L2CAP_CS_NO_INFO; } l2cap_connection_response(l2cap, cid, source_cid, result, status); return ch; } static void l2cap_channel_close(struct l2cap_instance_s *l2cap, int cid, int source_cid) { struct l2cap_chan_s *ch = NULL; /* According to Volume 3, section 6.1.1, pg 1048 of BT Core V2.0, a * connection in CLOSED state still responds with a L2CAP_DisconnectRsp * message on an L2CAP_DisconnectReq event. */ if (unlikely(cid < L2CAP_CID_ALLOC)) { l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL, cid, source_cid); return; } if (likely(cid >= L2CAP_CID_ALLOC && cid < L2CAP_CID_MAX)) ch = l2cap->cid[cid]; if (likely(ch)) { if (ch->remote_cid != source_cid) { fprintf(stderr, "%s: Ignoring a Disconnection Request with the " "invalid SCID %04x.\n", __FUNCTION__, source_cid); return; } l2cap->cid[cid] = NULL; ch->params.close(ch->params.opaque); g_free(ch); } l2cap_disconnection_response(l2cap, cid, source_cid); } static void l2cap_channel_config_null(struct l2cap_instance_s *l2cap, struct l2cap_chan_s *ch) { l2cap_configuration_request(l2cap, ch->remote_cid, 0, NULL, 0); ch->config_req_id = l2cap->last_id; ch->config &= ~L2CAP_CFG_INIT; } static void l2cap_channel_config_req_event(struct l2cap_instance_s *l2cap, struct l2cap_chan_s *ch) { /* Use all default channel options and terminate negotiation. */ l2cap_channel_config_null(l2cap, ch); } static int l2cap_channel_config(struct l2cap_instance_s *l2cap, struct l2cap_chan_s *ch, int flag, const uint8_t *data, int len) { l2cap_conf_opt *opt; l2cap_conf_opt_qos *qos; uint32_t val; uint8_t rsp[len]; int result = L2CAP_CONF_SUCCESS; data = memcpy(rsp, data, len); while (len) { opt = (void *) data; if (len < L2CAP_CONF_OPT_SIZE || len < L2CAP_CONF_OPT_SIZE + opt->len) { result = L2CAP_CONF_REJECT; break; } data += L2CAP_CONF_OPT_SIZE + opt->len; len -= L2CAP_CONF_OPT_SIZE + opt->len; switch (opt->type & 0x7f) { case L2CAP_CONF_MTU: if (opt->len != 2) { result = L2CAP_CONF_REJECT; break; } /* MTU */ val = le16_to_cpup((void *) opt->val); if (val < ch->min_mtu) { cpu_to_le16w((void *) opt->val, ch->min_mtu); result = L2CAP_CONF_UNACCEPT; break; } ch->params.remote_mtu = val; break; case L2CAP_CONF_FLUSH_TO: if (opt->len != 2) { result = L2CAP_CONF_REJECT; break; } /* Flush Timeout */ val = le16_to_cpup((void *) opt->val); if (val < 0x0001) { opt->val[0] = 0xff; opt->val[1] = 0xff; result = L2CAP_CONF_UNACCEPT; break; } break; case L2CAP_CONF_QOS: if (opt->len != L2CAP_CONF_OPT_QOS_SIZE) { result = L2CAP_CONF_REJECT; break; } qos = (void *) opt->val; /* Flags */ val = qos->flags; if (val) { qos->flags = 0; result = L2CAP_CONF_UNACCEPT; } /* Service type */ val = qos->service_type; if (val != L2CAP_CONF_QOS_BEST_EFFORT && val != L2CAP_CONF_QOS_NO_TRAFFIC) { qos->service_type = L2CAP_CONF_QOS_BEST_EFFORT; result = L2CAP_CONF_UNACCEPT; } if (val != L2CAP_CONF_QOS_NO_TRAFFIC) { /* XXX: These values should possibly be calculated * based on LM / baseband properties also. */ /* Token rate */ val = le32_to_cpu(qos->token_rate); if (val == L2CAP_CONF_QOS_WILDCARD) qos->token_rate = cpu_to_le32(0x100000); /* Token bucket size */ val = le32_to_cpu(qos->token_bucket_size); if (val == L2CAP_CONF_QOS_WILDCARD) qos->token_bucket_size = cpu_to_le32(65500); /* Any Peak bandwidth value is correct to return as-is */ /* Any Access latency value is correct to return as-is */ /* Any Delay variation value is correct to return as-is */ } break; case L2CAP_CONF_RFC: if (opt->len != 9) { result = L2CAP_CONF_REJECT; break; } /* Mode */ val = opt->val[0]; switch (val) { case L2CAP_MODE_BASIC: ch->mode = val; ch->frame_in = l2cap_bframe_in; /* All other parameters shall be ignored */ break; case L2CAP_MODE_RETRANS: case L2CAP_MODE_FLOWCTL: ch->mode = val; ch->frame_in = l2cap_iframe_in; /* Note: most of these parameters refer to incoming traffic * so we don't need to save them as long as we can accept * incoming PDUs at any values of the parameters. */ /* TxWindow size */ val = opt->val[1]; if (val < 1 || val > 32) { opt->val[1] = 32; result = L2CAP_CONF_UNACCEPT; break; } /* MaxTransmit */ val = opt->val[2]; if (val < 1) { opt->val[2] = 1; result = L2CAP_CONF_UNACCEPT; break; } /* Remote Retransmission time-out shouldn't affect local * operation (?) */ /* The Monitor time-out drives the local Monitor timer (?), * so save the value. */ val = (opt->val[6] << 8) | opt->val[5]; if (val < 30) { opt->val[5] = 100 & 0xff; opt->val[6] = 100 >> 8; result = L2CAP_CONF_UNACCEPT; break; } ch->monitor_timeout = val; l2cap_monitor_timer_update(ch); /* MPS */ val = (opt->val[8] << 8) | opt->val[7]; if (val < ch->min_mtu) { opt->val[7] = ch->min_mtu & 0xff; opt->val[8] = ch->min_mtu >> 8; result = L2CAP_CONF_UNACCEPT; break; } ch->mps = val; break; default: result = L2CAP_CONF_UNACCEPT; break; } break; default: if (!(opt->type >> 7)) result = L2CAP_CONF_UNKNOWN; break; } if (result != L2CAP_CONF_SUCCESS) break; /* XXX: should continue? */ } l2cap_configuration_response(l2cap, ch->remote_cid, flag, result, rsp, len); return result == L2CAP_CONF_SUCCESS && !flag; } static void l2cap_channel_config_req_msg(struct l2cap_instance_s *l2cap, int flag, int cid, const uint8_t *data, int len) { struct l2cap_chan_s *ch; if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) { l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL, cid, 0x0000); return; } ch = l2cap->cid[cid]; /* From OPEN go to WAIT_CONFIG_REQ and from WAIT_CONFIG_REQ_RSP to * WAIT_CONFIG_REQ_RSP. This is assuming the transition chart for OPEN * on pg 1053, section 6.1.5, volume 3 of BT Core V2.0 has a mistake * and on options-acceptable we go back to OPEN and otherwise to * WAIT_CONFIG_REQ and not the other way. */ ch->config &= ~L2CAP_CFG_ACC; if (l2cap_channel_config(l2cap, ch, flag, data, len)) /* Go to OPEN or WAIT_CONFIG_RSP */ ch->config |= L2CAP_CFG_ACC; /* TODO: if the incoming traffic flow control or retransmission mode * changed then we probably need to also generate the * ConfigureChannel_Req event and set the outgoing traffic to the same * mode. */ if (!(ch->config & L2CAP_CFG_INIT) && (ch->config & L2CAP_CFG_ACC) && !ch->config_req_id) l2cap_channel_config_req_event(l2cap, ch); } static int l2cap_channel_config_rsp_msg(struct l2cap_instance_s *l2cap, int result, int flag, int cid, const uint8_t *data, int len) { struct l2cap_chan_s *ch; if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) { l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL, cid, 0x0000); return 0; } ch = l2cap->cid[cid]; if (ch->config_req_id != l2cap->last_id) return 1; ch->config_req_id = 0; if (result == L2CAP_CONF_SUCCESS) { if (!flag) ch->config |= L2CAP_CFG_INIT; else l2cap_channel_config_null(l2cap, ch); } else /* Retry until we succeed */ l2cap_channel_config_req_event(l2cap, ch); return 0; } static void l2cap_channel_open_req_msg(struct l2cap_instance_s *l2cap, int psm, int source_cid) { struct l2cap_chan_s *ch = l2cap_channel_open(l2cap, psm, source_cid); if (!ch) return; /* Optional */ if (!(ch->config & L2CAP_CFG_INIT) && !ch->config_req_id) l2cap_channel_config_req_event(l2cap, ch); } static void l2cap_info(struct l2cap_instance_s *l2cap, int type) { uint8_t data[4]; int len = 0; int result = L2CAP_IR_SUCCESS; switch (type) { case L2CAP_IT_CL_MTU: data[len ++] = l2cap->group_ch.mps & 0xff; data[len ++] = l2cap->group_ch.mps >> 8; break; case L2CAP_IT_FEAT_MASK: /* (Prematurely) report Flow control and Retransmission modes. */ data[len ++] = 0x03; data[len ++] = 0x00; data[len ++] = 0x00; data[len ++] = 0x00; break; default: result = L2CAP_IR_NOTSUPP; } l2cap_info_response(l2cap, type, result, data, len); } static void l2cap_command(struct l2cap_instance_s *l2cap, int code, int id, const uint8_t *params, int len) { int err; #if 0 /* TODO: do the IDs really have to be in sequence? */ if (!id || (id != l2cap->last_id && id != l2cap->next_id)) { fprintf(stderr, "%s: out of sequence command packet ignored.\n", __FUNCTION__); return; } #else l2cap->next_id = id; #endif if (id == l2cap->next_id) { l2cap->last_id = l2cap->next_id; l2cap->next_id = l2cap->next_id == 255 ? 1 : l2cap->next_id + 1; } else { /* TODO: Need to re-send the same response, without re-executing * the corresponding command! */ } switch (code) { case L2CAP_COMMAND_REJ: if (unlikely(len != 2 && len != 4 && len != 6)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } /* We never issue commands other than Command Reject currently. */ fprintf(stderr, "%s: stray Command Reject (%02x, %04x) " "packet, ignoring.\n", __FUNCTION__, id, le16_to_cpu(((l2cap_cmd_rej *) params)->reason)); break; case L2CAP_CONN_REQ: if (unlikely(len != L2CAP_CONN_REQ_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } l2cap_channel_open_req_msg(l2cap, le16_to_cpu(((l2cap_conn_req *) params)->psm), le16_to_cpu(((l2cap_conn_req *) params)->scid)); break; case L2CAP_CONN_RSP: if (unlikely(len != L2CAP_CONN_RSP_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } /* We never issue Connection Requests currently. TODO */ fprintf(stderr, "%s: unexpected Connection Response (%02x) " "packet, ignoring.\n", __FUNCTION__, id); break; case L2CAP_CONF_REQ: if (unlikely(len < L2CAP_CONF_REQ_SIZE(0))) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } l2cap_channel_config_req_msg(l2cap, le16_to_cpu(((l2cap_conf_req *) params)->flags) & 1, le16_to_cpu(((l2cap_conf_req *) params)->dcid), ((l2cap_conf_req *) params)->data, len - L2CAP_CONF_REQ_SIZE(0)); break; case L2CAP_CONF_RSP: if (unlikely(len < L2CAP_CONF_RSP_SIZE(0))) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } if (l2cap_channel_config_rsp_msg(l2cap, le16_to_cpu(((l2cap_conf_rsp *) params)->result), le16_to_cpu(((l2cap_conf_rsp *) params)->flags) & 1, le16_to_cpu(((l2cap_conf_rsp *) params)->scid), ((l2cap_conf_rsp *) params)->data, len - L2CAP_CONF_RSP_SIZE(0))) fprintf(stderr, "%s: unexpected Configure Response (%02x) " "packet, ignoring.\n", __FUNCTION__, id); break; case L2CAP_DISCONN_REQ: if (unlikely(len != L2CAP_DISCONN_REQ_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } l2cap_channel_close(l2cap, le16_to_cpu(((l2cap_disconn_req *) params)->dcid), le16_to_cpu(((l2cap_disconn_req *) params)->scid)); break; case L2CAP_DISCONN_RSP: if (unlikely(len != L2CAP_DISCONN_RSP_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } /* We never issue Disconnection Requests currently. TODO */ fprintf(stderr, "%s: unexpected Disconnection Response (%02x) " "packet, ignoring.\n", __FUNCTION__, id); break; case L2CAP_ECHO_REQ: l2cap_echo_response(l2cap, params, len); break; case L2CAP_ECHO_RSP: /* We never issue Echo Requests currently. TODO */ fprintf(stderr, "%s: unexpected Echo Response (%02x) " "packet, ignoring.\n", __FUNCTION__, id); break; case L2CAP_INFO_REQ: if (unlikely(len != L2CAP_INFO_REQ_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } l2cap_info(l2cap, le16_to_cpu(((l2cap_info_req *) params)->type)); break; case L2CAP_INFO_RSP: if (unlikely(len != L2CAP_INFO_RSP_SIZE)) { err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; goto reject; } /* We never issue Information Requests currently. TODO */ fprintf(stderr, "%s: unexpected Information Response (%02x) " "packet, ignoring.\n", __FUNCTION__, id); break; default: err = L2CAP_REJ_CMD_NOT_UNDERSTOOD; reject: l2cap_command_reject(l2cap, id, err, 0, 0); break; } } static void l2cap_rexmit_enable(struct l2cap_chan_s *ch, int enable) { ch->rexmit = enable; l2cap_retransmission_timer_update(ch); l2cap_monitor_timer_update(ch); } /* Command frame SDU */ static void l2cap_cframe_in(void *opaque, const uint8_t *data, int len) { struct l2cap_instance_s *l2cap = opaque; const l2cap_cmd_hdr *hdr; int clen; while (len) { hdr = (void *) data; if (len < L2CAP_CMD_HDR_SIZE) /* TODO: signal an error */ return; len -= L2CAP_CMD_HDR_SIZE; data += L2CAP_CMD_HDR_SIZE; clen = le16_to_cpu(hdr->len); if (len < clen) { l2cap_command_reject(l2cap, hdr->ident, L2CAP_REJ_CMD_NOT_UNDERSTOOD, 0, 0); break; } l2cap_command(l2cap, hdr->code, hdr->ident, data, clen); len -= clen; data += clen; } } /* Group frame SDU */ static void l2cap_gframe_in(void *opaque, const uint8_t *data, int len) { } /* Supervisory frame */ static void l2cap_sframe_in(struct l2cap_chan_s *ch, uint16_t ctrl) { } /* Basic L2CAP mode Information frame */ static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid, const l2cap_hdr *hdr, int len) { /* We have a full SDU, no further processing */ ch->params.sdu_in(ch->params.opaque, hdr->data, len); } /* Flow Control and Retransmission mode frame */ static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid, const l2cap_hdr *hdr, int len) { uint16_t fcs = le16_to_cpup((void *) (hdr->data + len - 2)); if (len < 4) goto len_error; if (l2cap_fcs16((const uint8_t *) hdr, L2CAP_HDR_SIZE + len - 2) != fcs) goto fcs_error; if ((hdr->data[0] >> 7) == ch->rexmit) l2cap_rexmit_enable(ch, !(hdr->data[0] >> 7)); if (hdr->data[0] & 1) { if (len != 4) { /* TODO: Signal an error? */ return; } return l2cap_sframe_in(ch, le16_to_cpup((void *) hdr->data)); } switch (hdr->data[1] >> 6) { /* SAR */ case L2CAP_SAR_NO_SEG: if (ch->len_total) goto seg_error; if (len - 4 > ch->mps) goto len_error; return ch->params.sdu_in(ch->params.opaque, hdr->data + 2, len - 4); case L2CAP_SAR_START: if (ch->len_total || len < 6) goto seg_error; if (len - 6 > ch->mps) goto len_error; ch->len_total = le16_to_cpup((void *) (hdr->data + 2)); if (len >= 6 + ch->len_total) goto seg_error; ch->len_cur = len - 6; memcpy(ch->sdu, hdr->data + 4, ch->len_cur); break; case L2CAP_SAR_END: if (!ch->len_total || ch->len_cur + len - 4 < ch->len_total) goto seg_error; if (len - 4 > ch->mps) goto len_error; memcpy(ch->sdu + ch->len_cur, hdr->data + 2, len - 4); return ch->params.sdu_in(ch->params.opaque, ch->sdu, ch->len_total); case L2CAP_SAR_CONT: if (!ch->len_total || ch->len_cur + len - 4 >= ch->len_total) goto seg_error; if (len - 4 > ch->mps) goto len_error; memcpy(ch->sdu + ch->len_cur, hdr->data + 2, len - 4); ch->len_cur += len - 4; break; seg_error: len_error: /* TODO */ fcs_error: /* TODO */ ch->len_cur = 0; ch->len_total = 0; break; } } static void l2cap_frame_in(struct l2cap_instance_s *l2cap, const l2cap_hdr *frame) { uint16_t cid = le16_to_cpu(frame->cid); uint16_t len = le16_to_cpu(frame->len); if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) { fprintf(stderr, "%s: frame addressed to a non-existent L2CAP " "channel %04x received.\n", __FUNCTION__, cid); return; } l2cap->cid[cid]->frame_in(l2cap->cid[cid], cid, frame, len); } /* "Recombination" */ static void l2cap_pdu_in(struct l2cap_instance_s *l2cap, const uint8_t *data, int len) { const l2cap_hdr *hdr = (void *) l2cap->frame_in; if (unlikely(len + l2cap->frame_in_len > sizeof(l2cap->frame_in))) { if (l2cap->frame_in_len < sizeof(l2cap->frame_in)) { memcpy(l2cap->frame_in + l2cap->frame_in_len, data, sizeof(l2cap->frame_in) - l2cap->frame_in_len); l2cap->frame_in_len = sizeof(l2cap->frame_in); /* TODO: truncate */ l2cap_frame_in(l2cap, hdr); } return; } memcpy(l2cap->frame_in + l2cap->frame_in_len, data, len); l2cap->frame_in_len += len; if (len >= L2CAP_HDR_SIZE) if (len >= L2CAP_HDR_SIZE + le16_to_cpu(hdr->len)) l2cap_frame_in(l2cap, hdr); /* There is never a start of a new PDU in the same ACL packet, so * no need to memmove the remaining payload and loop. */ } static inline uint8_t *l2cap_pdu_out(struct l2cap_instance_s *l2cap, uint16_t cid, uint16_t len) { l2cap_hdr *hdr = (void *) l2cap->frame_out; l2cap->frame_out_len = len + L2CAP_HDR_SIZE; hdr->cid = cpu_to_le16(cid); hdr->len = cpu_to_le16(len); return l2cap->frame_out + L2CAP_HDR_SIZE; } static inline void l2cap_pdu_submit(struct l2cap_instance_s *l2cap) { /* TODO: Fragmentation */ (l2cap->role ? l2cap->link->slave->lmp_acl_data : l2cap->link->host->lmp_acl_resp) (l2cap->link, l2cap->frame_out, 1, l2cap->frame_out_len); } static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len) { struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm; if (len > chan->params.remote_mtu) { fprintf(stderr, "%s: B-Frame for CID %04x longer than %i octets.\n", __FUNCTION__, chan->remote_cid, chan->params.remote_mtu); exit(-1); } return l2cap_pdu_out(chan->l2cap, chan->remote_cid, len); } static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms) { struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parms; return l2cap_pdu_submit(chan->l2cap); } #if 0 /* Stub: Only used if an emulated device requests outgoing flow control */ static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len) { struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm; if (len > chan->params.remote_mtu) { /* TODO: slice into segments and queue each segment as a separate * I-Frame in a FIFO of I-Frames, local to the CID. */ } else { /* TODO: add to the FIFO of I-Frames, local to the CID. */ /* Possibly we need to return a pointer to a contiguous buffer * for now and then memcpy from it into FIFOs in l2cap_iframe_submit * while segmenting at the same time. */ } return 0; } static void l2cap_iframe_submit(struct bt_l2cap_conn_params_s *parm) { /* TODO: If flow control indicates clear to send, start submitting the * invidual I-Frames from the FIFO, but don't remove them from there. * Kick the appropriate timer until we get an S-Frame, and only then * remove from FIFO or resubmit and re-kick the timer if the timer * expired. */ } #endif static void l2cap_init(struct l2cap_instance_s *l2cap, struct bt_link_s *link, int role) { l2cap->link = link; l2cap->role = role; l2cap->dev = (struct bt_l2cap_device_s *) (role ? link->host : link->slave); l2cap->next_id = 1; /* Establish the signalling channel */ l2cap->signalling_ch.params.sdu_in = l2cap_cframe_in; l2cap->signalling_ch.params.sdu_out = l2cap_bframe_out; l2cap->signalling_ch.params.sdu_submit = l2cap_bframe_submit; l2cap->signalling_ch.params.opaque = l2cap; l2cap->signalling_ch.params.remote_mtu = 48; l2cap->signalling_ch.remote_cid = L2CAP_CID_SIGNALLING; l2cap->signalling_ch.frame_in = l2cap_bframe_in; l2cap->signalling_ch.mps = 65536; l2cap->signalling_ch.min_mtu = 48; l2cap->signalling_ch.mode = L2CAP_MODE_BASIC; l2cap->signalling_ch.l2cap = l2cap; l2cap->cid[L2CAP_CID_SIGNALLING] = &l2cap->signalling_ch; /* Establish the connection-less data channel */ l2cap->group_ch.params.sdu_in = l2cap_gframe_in; l2cap->group_ch.params.opaque = l2cap; l2cap->group_ch.frame_in = l2cap_bframe_in; l2cap->group_ch.mps = 65533; l2cap->group_ch.l2cap = l2cap; l2cap->group_ch.remote_cid = L2CAP_CID_INVALID; l2cap->cid[L2CAP_CID_GROUP] = &l2cap->group_ch; } static void l2cap_teardown(struct l2cap_instance_s *l2cap, int send_disconnect) { int cid; /* Don't send DISCONNECT if we are currently handling a DISCONNECT * sent from the other side. */ if (send_disconnect) { if (l2cap->role) l2cap->dev->device.lmp_disconnect_slave(l2cap->link); /* l2cap->link is invalid from now on. */ else l2cap->dev->device.lmp_disconnect_master(l2cap->link); } for (cid = L2CAP_CID_ALLOC; cid < L2CAP_CID_MAX; cid ++) if (l2cap->cid[cid]) { l2cap->cid[cid]->params.close(l2cap->cid[cid]->params.opaque); g_free(l2cap->cid[cid]); } if (l2cap->role) g_free(l2cap); else g_free(l2cap->link); } /* L2CAP glue to lower layers in bluetooth stack (LMP) */ static void l2cap_lmp_connection_request(struct bt_link_s *link) { struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->slave; struct slave_l2cap_instance_s *l2cap; /* Always accept - we only get called if (dev->device->page_scan). */ l2cap = g_malloc0(sizeof(struct slave_l2cap_instance_s)); l2cap->link.slave = &dev->device; l2cap->link.host = link->host; l2cap_init(&l2cap->l2cap, &l2cap->link, 0); /* Always at the end */ link->host->reject_reason = 0; link->host->lmp_connection_complete(&l2cap->link); } /* Stub */ static void l2cap_lmp_connection_complete(struct bt_link_s *link) { struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host; struct l2cap_instance_s *l2cap; if (dev->device.reject_reason) { /* Signal to upper layer */ return; } l2cap = g_malloc0(sizeof(struct l2cap_instance_s)); l2cap_init(l2cap, link, 1); link->acl_mode = acl_active; /* Signal to upper layer */ } /* Stub */ static void l2cap_lmp_disconnect_host(struct bt_link_s *link) { struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host; struct l2cap_instance_s *l2cap = /* TODO: Retrieve from upper layer */ (void *) dev; /* Signal to upper layer */ l2cap_teardown(l2cap, 0); } static void l2cap_lmp_disconnect_slave(struct bt_link_s *link) { struct slave_l2cap_instance_s *l2cap = (struct slave_l2cap_instance_s *) link; l2cap_teardown(&l2cap->l2cap, 0); } static void l2cap_lmp_acl_data_slave(struct bt_link_s *link, const uint8_t *data, int start, int len) { struct slave_l2cap_instance_s *l2cap = (struct slave_l2cap_instance_s *) link; if (start) l2cap->l2cap.frame_in_len = 0; l2cap_pdu_in(&l2cap->l2cap, data, len); } /* Stub */ static void l2cap_lmp_acl_data_host(struct bt_link_s *link, const uint8_t *data, int start, int len) { struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host; struct l2cap_instance_s *l2cap = /* TODO: Retrieve from upper layer */ (void *) dev; if (start) l2cap->frame_in_len = 0; l2cap_pdu_in(l2cap, data, len); } static void l2cap_dummy_destroy(struct bt_device_s *dev) { struct bt_l2cap_device_s *l2cap_dev = (struct bt_l2cap_device_s *) dev; bt_l2cap_device_done(l2cap_dev); } void bt_l2cap_device_init(struct bt_l2cap_device_s *dev, struct bt_scatternet_s *net) { bt_device_init(&dev->device, net); dev->device.lmp_connection_request = l2cap_lmp_connection_request; dev->device.lmp_connection_complete = l2cap_lmp_connection_complete; dev->device.lmp_disconnect_master = l2cap_lmp_disconnect_host; dev->device.lmp_disconnect_slave = l2cap_lmp_disconnect_slave; dev->device.lmp_acl_data = l2cap_lmp_acl_data_slave; dev->device.lmp_acl_resp = l2cap_lmp_acl_data_host; dev->device.handle_destroy = l2cap_dummy_destroy; } void bt_l2cap_device_done(struct bt_l2cap_device_s *dev) { bt_device_done(&dev->device); /* Should keep a list of all instances and go through it and * invoke l2cap_teardown() for each. */ } void bt_l2cap_psm_register(struct bt_l2cap_device_s *dev, int psm, int min_mtu, int (*new_channel)(struct bt_l2cap_device_s *dev, struct bt_l2cap_conn_params_s *params)) { struct bt_l2cap_psm_s *new_psm = l2cap_psm(dev, psm); if (new_psm) { fprintf(stderr, "%s: PSM %04x already registered for device `%s'.\n", __FUNCTION__, psm, dev->device.lmp_name); exit(-1); } new_psm = g_malloc0(sizeof(*new_psm)); new_psm->psm = psm; new_psm->min_mtu = min_mtu; new_psm->new_channel = new_channel; new_psm->next = dev->first_psm; dev->first_psm = new_psm; }