'\" t .\" Man page generated from reStructuredText. . . .nr rst2man-indent-level 0 . .de1 rstReportMargin \\$1 \\n[an-margin] level \\n[rst2man-indent-level] level margin: \\n[rst2man-indent\\n[rst2man-indent-level]] - \\n[rst2man-indent0] \\n[rst2man-indent1] \\n[rst2man-indent2] .. .de1 INDENT .\" .rstReportMargin pre: . RS \\$1 . nr rst2man-indent\\n[rst2man-indent-level] \\n[an-margin] . nr rst2man-indent-level +1 .\" .rstReportMargin post: .. .de UNINDENT . RE .\" indent \\n[an-margin] .\" old: \\n[rst2man-indent\\n[rst2man-indent-level]] .nr rst2man-indent-level -1 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]] .in \\n[rst2man-indent\\n[rst2man-indent-level]]u .. .TH "SCO" "7" "March 2025" "BlueZ" "Linux System Administration" .SH NAME sco \- SCO transport .SH SYNOPSIS .INDENT 0.0 .INDENT 3.5 .sp .EX #include #include #include sco_socket = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO); .EE .UNINDENT .UNINDENT .SH DESCRIPTION .sp The SCO logical transport, is a symmetric, point\-to\-point transport between the Central and a specific Peripheral. The SCO logical transport reserves slots and can therefore be considered as a circuit\-switched connection between the Central and the Peripheral. .sp In addition to the reserved slots, when eSCO is supported, a retransmission window follows immediately after. Together, the reserved slots and the retransmission window form the complete eSCO window. .SH SOCKET ADDRESS .INDENT 0.0 .INDENT 3.5 .sp .EX struct sockaddr_sco { sa_family_t sco_family; bdaddr_t sco_bdaddr; }; .EE .UNINDENT .UNINDENT .sp Example: .INDENT 0.0 .INDENT 3.5 .sp .EX struct sockaddr_sco addr; memset(&addr, 0, sizeof(addr)); addr.sco_family = AF_BLUETOOTH; bacpy(&addr.sco_bdaddr, bdaddr); .EE .UNINDENT .UNINDENT .SH SOCKET OPTIONS .sp The socket options listed below can be set by using \fBsetsockopt(2)\fP and read with \fBgetsockopt(2)\fP with the socket level set to SOL_BLUETOOTH. .SS BT_SECURITY (since Linux 2.6.30) .sp Channel security level, possible values: .TS box center; l|l|l|l. T{ Value T} T{ Security Level T} T{ Link Key Type T} T{ Encryption T} _ T{ \fBBT_SECURITY_SDP\fP T} T{ 0 (SDP Only) T} T{ None T} T{ Not required T} _ T{ \fBBT_SECURITY_LOW\fP T} T{ 1 (Low) T} T{ Unauthenticated T} T{ Not required T} _ T{ \fBBT_SECURITY_MEDIUM\fP T} T{ 2 (Medium \- default) T} T{ Unauthenticated T} T{ Desired T} _ T{ \fBBT_SECURITY_HIGH\fP T} T{ 3 (High) T} T{ Authenticated T} T{ Required T} _ T{ \fBBT_SECURITY_FIPS\fP (since Linux 3.15) T} T{ 4 (Secure Only) T} T{ Authenticated (P\-256 based Secure Simple Pairing and Secure Authentication) T} T{ Required T} .TE .sp Example: .INDENT 0.0 .INDENT 3.5 .sp .EX int level = BT_SECURITY_HIGH; int err = setsockopt(sco_socket, SOL_BLUETOOTH, BT_SECURITY, &level, sizeof(level)); if (err == \-1) { perror(\(dqsetsockopt\(dq); return 1; } .EE .UNINDENT .UNINDENT .SS BT_DEFER_SETUP (since Linux 2.6.30) .sp Channel defer connection setup, this control if the connection procedure needs to be authorized by userspace before responding which allows authorization at profile level, possible values: .TS box center; l|l|l. T{ Value T} T{ Description T} T{ Authorization T} _ T{ \fB0\fP T} T{ Disable (default) T} T{ Not required T} _ T{ \fB1\fP T} T{ Enable T} T{ Required T} .TE .sp Example: .INDENT 0.0 .INDENT 3.5 .sp .EX int defer_setup = 1; int err = setsockopt(sco_socket, SOL_BLUETOOTH, BT_DEFER_SETUP, &defer_setup, sizeof(defer_setup)); if (err == \-1) { perror(\(dqsetsockopt\(dq); return err; } err = listen(sco_socket, 5); if (err) { perror(\(dqlisten\(dq); return err; } struct sockaddr_sco remote_addr = {0}; socklen_t addr_len = sizeof(remote_addr); int new_socket = accept(sco_socket, (struct sockaddr*)&remote_addr, &addr_len); if (new_socket < 0) { perror(\(dqaccept\(dq); return new_socket; } /* To complete the connection setup of new_socket read 1 byte */ char c; struct pollfd pfd; memset(&pfd, 0, sizeof(pfd)); pfd.fd = new_socket; pfd.events = POLLOUT; err = poll(&pfd, 1, 0); if (err) { perror(\(dqpoll\(dq); return err; } if (!(pfd.revents & POLLOUT)) { err = read(sk, &c, 1); if (err < 0) { perror(\(dqread\(dq); return err; } } .EE .UNINDENT .UNINDENT .SS BT_VOICE (since Linux 3.11) .sp Transport voice settings, possible values: .INDENT 0.0 .INDENT 3.5 .sp .EX struct bt_voice { uint16_t setting; }; .EE .UNINDENT .UNINDENT .TS box center; l|l|l. T{ Define T} T{ Value T} T{ Description T} _ T{ \fBBT_VOICE_TRANSPARENT\fP T} T{ 0x0003 T} T{ Transparent output T} _ T{ \fBBT_VOICE_CVSD_16BIT\fP T} T{ 0x0060 T} T{ C\-VSD output PCM 16\-bit input T} _ T{ \fBBT_VOICE_TRANSPARENT_16BIT\fP T} T{ 0x0063 T} T{ Transparent output PCM 16\-bit input T} .TE .sp Example: .INDENT 0.0 .INDENT 3.5 .sp .EX struct bt_voice voice; memset(&voice, 0, sizeof(voice)); voice.setting = BT_VOICE_TRANSPARENT; int err = setsockopt(sco_socket, SOL_BLUETOOTH, BT_VOICE, &voice, sizeof(voice)); if (err == \-1) { perror(\(dqsetsockopt\(dq); return 1; } .EE .UNINDENT .UNINDENT .SS BT_PHY (since Linux 5.10) .sp Transport supported PHY(s), possible values: .TS box center; l|l|l. T{ Define T} T{ Value T} T{ Description T} _ T{ \fBBT_PHY_BR_1M_1SLOT\fP T} T{ BIT 0 T} T{ BR 1Mbps 1SLOT T} _ T{ \fBBT_PHY_BR_1M_3SLOT\fP T} T{ BIT 1 T} T{ BR 1Mbps 3SLOT T} _ T{ \fBBT_PHY_BR_2M_1SLOT\fP T} T{ BIT 3 T} T{ EDR 2Mbps 1SLOT T} _ T{ \fBBT_PHY_BR_2M_3SLOT\fP T} T{ BIT 4 T} T{ EDR 2Mbps 3SLOT T} _ T{ \fBBT_PHY_BR_3M_1SLOT\fP T} T{ BIT 6 T} T{ EDR 3Mbps 1SLOT T} _ T{ \fBBT_PHY_BR_3M_3SLOT\fP T} T{ BIT 7 T} T{ EDR 3Mbps 3SLOT T} .TE .SS BT_CODEC (since Linux 5.14) .sp Transport codec offload, possible values: .INDENT 0.0 .INDENT 3.5 .sp .EX struct bt_codec { uint8_t id; uint16_t cid; uint16_t vid; uint8_t data_path_id; uint8_t num_caps; struct codec_caps { uint8_t len; uint8_t data[]; } caps[]; } __attribute__((packed)); struct bt_codecs { uint8_t num_codecs; struct bt_codec codecs[]; } __attribute__((packed)); .EE .UNINDENT .UNINDENT .sp Example: .INDENT 0.0 .INDENT 3.5 .sp .EX char buffer[sizeof(struct bt_codecs) + sizeof(struct bt_codec)]; struct bt_codec *codecs = (void *)buffer; memset(codecs, 0, sizeof(codecs)); codec\->num_codecs = 1; codecs\->codecs[0].id = 0x05; codecs\->codecs[0].data_path_id = 1; int err = setsockopt(sco_socket, SOL_BLUETOOTH, BT_CODEC, codecs, sizeof(buffer)); if (err == \-1) { perror(\(dqsetsockopt\(dq); return 1; } .EE .UNINDENT .UNINDENT .SH RESOURCES .sp .SH REPORTING BUGS .sp .SH SEE ALSO .sp socket(7), scotest(1) .SH COPYRIGHT Free use of this software is granted under the terms of the GNU Lesser General Public Licenses (LGPL). .\" Generated by docutils manpage writer. .