diff --git a/man/tio.1.in b/man/tio.1.in index 38c44d8..f038295 100644 --- a/man/tio.1.in +++ b/man/tio.1.in @@ -114,6 +114,17 @@ Colorize tio text using ANSI color code ranging from 0 to 255. If color code is negative a list of available ANSI colors will be printed. +.TP +.BR \-S ", " "\-\-socket unix:\fI\fR\fB + +Listen on a Unix domain socket at the specified path. Any input from clients connected to the socket is sent on the serial port as if entered at the terminal where tio is running (except that +.B ctrl-t +sequences are not recognized), and any input from the serial port is multiplexed to the terminal and all connected clients. + +Sockets remain open while the serial port is disconnected, and writes will block. + +At present there is a hardcoded limit of 16 clients connected at one time. + .TP .BR \-v ", " \-\-version @@ -201,6 +212,9 @@ Set log filename Map special characters on input or output .IP "\fBcolor" Colorize tio text using ANSI color code ranging from 0 to 255. +.IP "\fBsocket" +Set socket path (must include +.BR unix: ). .SH "CONFIGURATION EXAMPLES" diff --git a/src/bash-completion/tio.in b/src/bash-completion/tio.in index d64d7e3..58da18d 100644 --- a/src/bash-completion/tio.in +++ b/src/bash-completion/tio.in @@ -80,6 +80,10 @@ _tio() COMPREPLY=( $(compgen -W "$(seq 0 255)" -- ${cur}) ) return 0 ;; + -S | --socket) + COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) ) + return 0 + ;; -v | --version) COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) ) return 0 diff --git a/src/configfile.c b/src/configfile.c index 9d11023..392ad46 100644 --- a/src/configfile.c +++ b/src/configfile.c @@ -152,6 +152,11 @@ static int data_handler(void *user, const char *section, const char *name, { option.color = atoi(value); } + else if (!strcmp(name, "socket")) + { + asprintf(&c->socket, "%s", value); + option.socket = c->socket; + } } return 0; } diff --git a/src/configfile.h b/src/configfile.h index 7d94273..57ae2a1 100644 --- a/src/configfile.h +++ b/src/configfile.h @@ -34,6 +34,7 @@ struct config_t char *flow; char *parity; char *log_filename; + char *socket; char *map; }; diff --git a/src/main.c b/src/main.c index 44cedf2..7f0fe4a 100644 --- a/src/main.c +++ b/src/main.c @@ -30,6 +30,7 @@ #include "error.h" #include "print.h" #include "signals.h" +#include "socket.h" int main(int argc, char *argv[]) { @@ -71,6 +72,9 @@ int main(int argc, char *argv[]) if (option.log) log_open(option.log_filename); + /* Open socket */ + socket_configure(); + /* Enable ANSI text formatting (colors etc.) */ print_enable_ansi_formatting(); diff --git a/src/meson.build b/src/meson.build index 6f1e737..38d300a 100644 --- a/src/meson.build +++ b/src/meson.build @@ -12,7 +12,8 @@ tio_sources = [ 'tty.c', 'print.c', 'configfile.c', - 'signals.c' + 'signals.c', + 'socket.c' ] tio_dep = dependency('inih', required: true, diff --git a/src/options.c b/src/options.c index fc24974..0ab7147 100644 --- a/src/options.c +++ b/src/options.c @@ -51,6 +51,7 @@ struct option_t option = .timestamp = TIMESTAMP_NONE, .list_devices = false, .log_filename = "", + .socket = NULL, .map = "", .color = -1, }; @@ -73,6 +74,7 @@ void print_help(char *argv[]) printf(" -l, --log[=] Log to file\n"); printf(" -m, --map Map special characters\n"); printf(" -c, --color Colorize tio text\n"); + printf(" -S, --socket Listen on domain socket\n"); printf(" -v, --version Display version\n"); printf(" -h, --help Display help\n"); printf("\n"); @@ -174,6 +176,7 @@ void options_parse(int argc, char *argv[]) {"timestamp", optional_argument, 0, 't'}, {"list-devices", no_argument, 0, 'L'}, {"log", optional_argument, 0, 'l'}, + {"socket", required_argument, 0, 'S'}, {"map", required_argument, 0, 'm'}, {"color", required_argument, 0, 'c'}, {"version", no_argument, 0, 'v'}, @@ -185,7 +188,7 @@ void options_parse(int argc, char *argv[]) int option_index = 0; /* Parse argument using getopt_long */ - c = getopt_long(argc, argv, "b:d:f:s:p:o:net::Ll::m:c:vh", long_options, &option_index); + c = getopt_long(argc, argv, "b:d:f:s:p:o:net::Ll:S::m:c:vh", long_options, &option_index); /* Detect the end of the options */ if (c == -1) @@ -248,6 +251,10 @@ void options_parse(int argc, char *argv[]) option.log_filename = optarg; break; + case 'S': + option.socket = optarg; + break; + case 'm': option.map = optarg; break; diff --git a/src/options.h b/src/options.h index 8010602..98bec82 100644 --- a/src/options.h +++ b/src/options.h @@ -53,6 +53,7 @@ struct option_t bool list_devices; const char *log_filename; const char *map; + const char *socket; int color; }; diff --git a/src/socket.c b/src/socket.c new file mode 100644 index 0000000..b254a29 --- /dev/null +++ b/src/socket.c @@ -0,0 +1,195 @@ +/* + * tio - a simple serial terminal I/O tool + * + * Copyright (c) 2014-2022 Martin Lund + * Copyright (c) 2022 Google LLC + * + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include "socket.h" +#include "options.h" +#include "print.h" + +#include +#include +#include +#include +#include +#include + +#define MAX_SOCKET_CLIENTS 16 + +static int sockfd; +static int clientfds[MAX_SOCKET_CLIENTS]; + +static const char *socket_filename(void) +{ + /* skip 'unix:' */ + return option.socket + 5; +} + +static void socket_exit(void) +{ + unlink(socket_filename()); +} + +void socket_configure(void) +{ + if (!option.socket) + { + return; + } + + if (strncmp(option.socket, "unix:", 5) != 0) + { + error_printf("%s: Invalid socket scheme, must be 'unix:'", option.socket); + exit(EXIT_FAILURE); + } + + struct sockaddr_un sockaddr = {}; + if (strlen(socket_filename()) > sizeof(sockaddr.sun_path) - 1) + { + error_printf("Socket file path %s too long", option.socket); + exit(EXIT_FAILURE); + } + + sockaddr.sun_family = AF_UNIX; + strncpy(sockaddr.sun_path, socket_filename(), sizeof(sockaddr.sun_path) - 1); + + sockfd = socket(AF_UNIX, SOCK_STREAM, 0); + if (sockfd < 0) + { + error_printf("Failed to create socket: %s", strerror(errno)); + exit(EXIT_FAILURE); + } + + unlink(socket_filename()); + if (bind(sockfd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) + { + error_printf("Failed to bind to socket %s: %s", socket_filename(), strerror(errno)); + exit(EXIT_FAILURE); + } + + if (listen(sockfd, MAX_SOCKET_CLIENTS) < 0) + { + error_printf("Failed to listen on socket %s: %s", socket_filename(), strerror(errno)); + exit(EXIT_FAILURE); + } + + memset(clientfds, -1, sizeof(clientfds)); + atexit(socket_exit); +} + +void socket_write(char input_char) +{ + if (!option.socket) + { + return; + } + + for (int i = 0; i != MAX_SOCKET_CLIENTS; ++i) + { + if (clientfds[i] != -1) + { + if (write(clientfds[i], &input_char, 1) <= 0) + { + error_printf_silent("Failed to write to socket: %s", strerror(errno)); + close(clientfds[i]); + clientfds[i] = -1; + } + } + } +} + +int socket_add_fds(fd_set *rdfs, bool connected) +{ + if (!option.socket) + { + return 0; + } + + int numclients = 0, maxfd = 0; + for (int i = 0; i != MAX_SOCKET_CLIENTS; ++i) + { + if (clientfds[i] != -1) + { + /* let clients block if they try to send while we're disconnected */ + if (connected) + { + FD_SET(clientfds[i], rdfs); + maxfd = MAX(maxfd, clientfds[i]); + } + numclients++; + } + } + /* don't bother to accept clients if we're already full */ + if (numclients != MAX_SOCKET_CLIENTS) + { + FD_SET(sockfd, rdfs); + maxfd = MAX(maxfd, sockfd); + } + return maxfd; +} + +bool socket_handle_input(fd_set *rdfs, char *output_char) +{ + if (!option.socket) + { + return false; + } + + if (FD_ISSET(sockfd, rdfs)) + { + int clientfd = accept(sockfd, NULL, NULL); + /* this loop should always succeed because we don't select on sockfd when full */ + for (int i = 0; i != MAX_SOCKET_CLIENTS; ++i) + { + if (clientfds[i] == -1) + { + clientfds[i] = clientfd; + break; + } + } + } + for (int i = 0; i != MAX_SOCKET_CLIENTS; ++i) + { + if (clientfds[i] != -1 && FD_ISSET(clientfds[i], rdfs)) + { + int status = read(clientfds[i], output_char, 1); + if (status == 0) + { + close(clientfds[i]); + clientfds[i] = -1; + continue; + } + if (status < 0) + { + error_printf_silent("Failed to read from socket: %s", strerror(errno)); + close(clientfds[i]); + clientfds[i] = -1; + continue; + } + /* match the behavior of a terminal in raw mode */ + if (*output_char == '\n') + { + *output_char = '\r'; + } + return true; + } + } + return false; +} diff --git a/src/socket.h b/src/socket.h new file mode 100644 index 0000000..2caffaf --- /dev/null +++ b/src/socket.h @@ -0,0 +1,31 @@ +/* + * tio - a simple serial terminal I/O tool + * + * Copyright (c) 2014-2022 Martin Lund + * Copyright (c) 2022 Google LLC + * + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#pragma once + +#include +#include + +void socket_configure(void); +void socket_write(char input_char); +int socket_add_fds(fd_set *fds, bool connected); +bool socket_handle_input(fd_set *fds, char *output_char); diff --git a/src/tty.c b/src/tty.c index 9667ac9..613e1fa 100644 --- a/src/tty.c +++ b/src/tty.c @@ -31,6 +31,8 @@ #include #include #include +#include +#include #include #include #include @@ -45,6 +47,7 @@ #include "misc.h" #include "log.h" #include "error.h" +#include "socket.h" #ifdef HAVE_TERMIOS2 extern int setspeed2(int fd, int baudrate); @@ -494,6 +497,7 @@ void tty_wait_for_device(void) { fd_set rdfs; int status; + int maxfd; struct timeval tv; static char input_char, previous_char = 0; static bool first = true; @@ -517,26 +521,30 @@ void tty_wait_for_device(void) FD_ZERO(&rdfs); FD_SET(STDIN_FILENO, &rdfs); + maxfd = MAX(STDIN_FILENO, socket_add_fds(&rdfs, false)); /* Block until input becomes available or timeout */ - status = select(STDIN_FILENO + 1, &rdfs, NULL, NULL, &tv); + status = select(maxfd + 1, &rdfs, NULL, NULL, &tv); if (status > 0) { - /* Input from stdin ready */ - - /* Read one character */ - status = read(STDIN_FILENO, &input_char, 1); - if (status <= 0) + if (FD_ISSET(STDIN_FILENO, &rdfs)) { - error_printf("Could not read from stdin"); - exit(EXIT_FAILURE); + /* Input from stdin ready */ + + /* Read one character */ + status = read(STDIN_FILENO, &input_char, 1); + if (status <= 0) + { + error_printf("Could not read from stdin"); + exit(EXIT_FAILURE); + } + + /* Handle commands */ + handle_command_sequence(input_char, previous_char, NULL, NULL); + + previous_char = input_char; } - - /* Handle commands */ - handle_command_sequence(input_char, previous_char, NULL, NULL); - - previous_char = input_char; - + socket_handle_input(&rdfs, NULL); } else if (status == -1) { error_printf("select() failed (%s)", strerror(errno)); @@ -686,19 +694,20 @@ int tty_connect(void) } #endif - maxfd = MAX(fd, STDIN_FILENO) + 1; /* Maximum bit entry (fd) to test */ - /* Input loop */ while (true) { FD_ZERO(&rdfs); FD_SET(fd, &rdfs); FD_SET(STDIN_FILENO, &rdfs); + maxfd = MAX(fd, STDIN_FILENO); + maxfd = MAX(maxfd, socket_add_fds(&rdfs, true)); /* Block until input becomes available */ - status = select(maxfd, &rdfs, NULL, NULL, NULL); + status = select(maxfd + 1, &rdfs, NULL, NULL, NULL); if (status > 0) { + bool forward = false; if (FD_ISSET(fd, &rdfs)) { /* Input from tty device ready */ @@ -747,6 +756,8 @@ int tty_connect(void) if (option.log) log_write(input_char); + socket_write(input_char); + print_tainted = true; if (input_char == '\n' && option.timestamp) @@ -760,7 +771,7 @@ int tty_connect(void) } if (FD_ISSET(STDIN_FILENO, &rdfs)) { - bool forward = true; + forward = true; /* Input from stdin ready */ status = read(STDIN_FILENO, &input_char, 1); @@ -778,47 +789,51 @@ int tty_connect(void) /* Handle commands */ handle_command_sequence(input_char, previous_char, &output_char, &forward); - if (forward) - { - /* Map output character */ - if ((output_char == 127) && (map_o_del_bs)) - output_char = '\b'; - if ((output_char == '\r') && (map_o_cr_nl)) - output_char = '\n'; - - /* Map newline character */ - if ((output_char == '\n' || output_char == '\r') && (map_o_nl_crnl)) { - const char *crlf = "\r\n"; - - optional_local_echo(crlf[0]); - optional_local_echo(crlf[1]); - status = write(fd, crlf, 2); - if (status < 0) - warning_printf("Could not write to tty device"); - - tx_total += 2; - delay(option.output_delay); - } else - { - /* Send output to tty device */ - optional_local_echo(output_char); - status = write(fd, &output_char, 1); - if (status < 0) - warning_printf("Could not write to tty device"); - fsync(fd); - - /* Update transmit statistics */ - tx_total++; - - /* Insert output delay */ - delay(option.output_delay); - } - } - /* Save previous key */ previous_char = input_char; } + else + { + forward = socket_handle_input(&rdfs, &output_char); + } + + if (forward) + { + /* Map output character */ + if ((output_char == 127) && (map_o_del_bs)) + output_char = '\b'; + if ((output_char == '\r') && (map_o_cr_nl)) + output_char = '\n'; + + /* Map newline character */ + if ((output_char == '\n' || output_char == '\r') && (map_o_nl_crnl)) { + const char *crlf = "\r\n"; + + optional_local_echo(crlf[0]); + optional_local_echo(crlf[1]); + status = write(fd, crlf, 2); + if (status < 0) + warning_printf("Could not write to tty device"); + + tx_total += 2; + delay(option.output_delay); + } else + { + /* Send output to tty device */ + optional_local_echo(output_char); + status = write(fd, &output_char, 1); + if (status < 0) + warning_printf("Could not write to tty device"); + fsync(fd); + + /* Update transmit statistics */ + tx_total++; + + /* Insert output delay */ + delay(option.output_delay); + } + } } else if (status == -1) { error_printf("Error: select() failed (%s)", strerror(errno));