diff options
Diffstat (limited to 'erts/etc/unix/to_erl.c')
| -rw-r--r-- | erts/etc/unix/to_erl.c | 591 |
1 files changed, 587 insertions, 4 deletions
diff --git a/erts/etc/unix/to_erl.c b/erts/etc/unix/to_erl.c index 82d3218964..0bd469727c 100644 --- a/erts/etc/unix/to_erl.c +++ b/erts/etc/unix/to_erl.c @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 1996-2013. All Rights Reserved. + * Copyright Ericsson AB 1996-2015. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -17,9 +17,592 @@ * * %CopyrightEnd% */ +/* + * Module: to_erl.c + * + * This module implements a process that opens two specified FIFOs, one + * for reading and one for writing; reads from its stdin, and writes what + * it has read to the write FIF0; reads from the read FIFO, and writes to + * its stdout. + * + ________ _________ + | |--<-- pipe.r (fifo1) --<--| | + | to_erl | | run_erl | (parent) + |________|-->-- pipe.w (fifo2) -->--|_________| + ^ master pty + | + | slave pty + ____V____ + | | + | "erl" | (child) + |_________| + */ +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <termios.h> +#include <dirent.h> +#include <signal.h> +#include <errno.h> +#ifdef HAVE_SYS_IOCTL_H +# include <sys/ioctl.h> +#endif + +#include "run_erl.h" +#include "safe_string.h" /* strn_cpy, strn_catf, sn_printf, etc. */ + +#if defined(O_NONBLOCK) +# define DONT_BLOCK_PLEASE O_NONBLOCK +#else +# define DONT_BLOCK_PLEASE O_NDELAY +# if !defined(EAGAIN) +# define EAGAIN -3898734 +# endif +#endif + +#ifdef HAVE_STRERROR +# define STRERROR(x) strerror(x) +#else +# define STRERROR(x) "" +#endif + +#define noDEBUG + +#define PIPE_DIR "/tmp/" +#define PIPE_STUBNAME "erlang.pipe" +#define PIPE_STUBLEN strlen(PIPE_STUBNAME) + +#ifdef DEBUG +#define STATUS(s) { fprintf(stderr, (s)); fflush(stderr); } +#else +#define STATUS(s) +#endif + +#ifndef FILENAME_MAX +#define FILENAME_MAX 250 +#endif + +static struct termios tty_smode, tty_rmode; +static int tty_eof = 0; +static int recv_sig = 0; +static int protocol_ver = RUN_ERL_LO_VER; /* assume lowest to begin with */ + +static int write_all(int fd, const char* buf, int len); +static int window_size_seq(char* buf, size_t bufsz); +static int version_handshake(char* buf, int len, int wfd); +#ifdef DEBUG +static void show_terminal_settings(struct termios *); +#endif + +static void handle_ctrlc(int sig) +{ + /* Reinstall the handler, and signal break flag */ + signal(SIGINT,handle_ctrlc); + recv_sig = SIGINT; +} + +static void handle_sigwinch(int sig) +{ + recv_sig = SIGWINCH; +} + +static void usage(char *pname) +{ + fprintf(stderr, "Usage: %s [-h|-F] [pipe_name|pipe_dir/]\n", pname); + fprintf(stderr, "\t-h\tThis help text.\n"); + fprintf(stderr, "\t-F\tForce connection even though pipe is locked by other to_erl process.\n"); +} + +int main(int argc, char **argv) +{ + char FIFO1[FILENAME_MAX], FIFO2[FILENAME_MAX]; + int i, len, wfd, rfd; + fd_set readfds; + char buf[BUFSIZ]; + char pipename[FILENAME_MAX]; + int pipeIx = 1; + int force_lock = 0; + int got_some = 0; + + if (argc >= 2 && argv[1][0]=='-') { + switch (argv[1][1]) { + case 'h': + usage(argv[0]); + exit(1); + case 'F': + force_lock = 1; + break; + default: + fprintf(stderr,"Invalid option '%s'\n",argv[1]); + exit(1); + } + pipeIx = 2; + } + +#ifdef DEBUG + fprintf(stderr, "%s: pid is : %d\n", argv[0], (int)getpid()); +#endif + + strn_cpy(pipename, sizeof(pipename), + (argv[pipeIx] ? argv[pipeIx] : PIPE_DIR)); + + if(*pipename && pipename[strlen(pipename)-1] == '/') { + /* The user wishes us to find a pipe name in the specified */ + /* directory */ + int highest_pipe_num = 0; + DIR *dirp; + struct dirent *direntp; + + dirp = opendir(pipename); + if(!dirp) { + fprintf(stderr, "Can't access pipe directory %s: %s\n", pipename, strerror(errno)); + exit(1); + } + + /* Check the directory for existing pipes */ + + while((direntp=readdir(dirp)) != NULL) { + if(strncmp(direntp->d_name,PIPE_STUBNAME,PIPE_STUBLEN)==0) { + int num = atoi(direntp->d_name+PIPE_STUBLEN+1); + if(num > highest_pipe_num) + highest_pipe_num = num; + } + } + closedir(dirp); + strn_catf(pipename, sizeof(pipename), (highest_pipe_num?"%s.%d":"%s"), + PIPE_STUBNAME, highest_pipe_num); + } /* if */ + + /* read FIFO */ + sn_printf(FIFO1,sizeof(FIFO1),"%s.r",pipename); + /* write FIFO */ + sn_printf(FIFO2,sizeof(FIFO2),"%s.w",pipename); + + /* Check that nobody is running to_erl on this pipe already */ + if ((wfd = open (FIFO1, O_WRONLY|DONT_BLOCK_PLEASE, 0)) >= 0) { + /* Open as server succeeded -- to_erl is already running! */ + close(wfd); + fprintf(stderr, "Another to_erl process already attached to pipe " + "%s.\n", pipename); + if (force_lock) { + fprintf(stderr, "But we proceed anyway by force (-F).\n"); + } + else { + exit(1); + } + } + + if ((rfd = open (FIFO1, O_RDONLY|DONT_BLOCK_PLEASE, 0)) < 0) { +#ifdef DEBUG + fprintf(stderr, "Could not open FIFO %s for reading.\n", FIFO1); +#endif + fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno)); + exit(1); + } +#ifdef DEBUG + fprintf(stderr, "to_erl: %s opened for reading\n", FIFO1); +#endif + + if ((wfd = open (FIFO2, O_WRONLY|DONT_BLOCK_PLEASE, 0)) < 0) { +#ifdef DEBUG + fprintf(stderr, "Could not open FIFO %s for writing.\n", FIFO2); +#endif + fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno)); + close(rfd); + exit(1); + } +#ifdef DEBUG + fprintf(stderr, "to_erl: %s opened for writing\n", FIFO2); +#endif + + fprintf(stderr, "Attaching to %s (^D to exit)\n\n", pipename); + + /* Set break handler to our handler */ + signal(SIGINT,handle_ctrlc); + + /* + * Save the current state of the terminal, and set raw mode. + */ + if (tcgetattr(0, &tty_rmode) , 0) { + fprintf(stderr, "Cannot get terminals current mode\n"); + exit(-1); + } + tty_smode = tty_rmode; + tty_eof = '\004'; /* Ctrl+D to exit */ +#ifdef DEBUG + show_terminal_settings(&tty_rmode); +#endif + tty_smode.c_iflag = + 1*BRKINT |/*Signal interrupt on break.*/ + 1*IGNPAR |/*Ignore characters with parity errors.*/ + 1*ISTRIP |/*Strip character.*/ + 0; + +#if 0 +0*IGNBRK |/*Ignore break condition.*/ +0*PARMRK |/*Mark parity errors.*/ +0*INPCK |/*Enable input parity check.*/ +0*INLCR |/*Map NL to CR on input.*/ +0*IGNCR |/*Ignore CR.*/ +0*ICRNL |/*Map CR to NL on input.*/ +0*IUCLC |/*Map upper-case to lower-case on input.*/ +0*IXON |/*Enable start/stop output control.*/ +0*IXANY |/*Enable any character to restart output.*/ +0*IXOFF |/*Enable start/stop input control.*/ +0*IMAXBEL|/*Echo BEL on input line too long.*/ +#endif + + tty_smode.c_oflag = + 1*OPOST |/*Post-process output.*/ + 1*ONLCR |/*Map NL to CR-NL on output.*/ +#ifdef XTABS + 1*XTABS |/*Expand tabs to spaces. (Linux)*/ +#endif +#ifdef OXTABS + 1*OXTABS |/*Expand tabs to spaces. (FreeBSD)*/ +#endif +#ifdef NL0 + 1*NL0 |/*Select newline delays*/ +#endif +#ifdef CR0 + 1*CR0 |/*Select carriage-return delays*/ +#endif +#ifdef TAB0 + 1*TAB0 |/*Select horizontal tab delays*/ +#endif +#ifdef BS0 + 1*BS0 |/*Select backspace delays*/ +#endif +#ifdef VT0 + 1*VT0 |/*Select vertical tab delays*/ +#endif +#ifdef FF0 + 1*FF0 |/*Select form feed delays*/ +#endif + 0; + +#if 0 +0*OLCUC |/*Map lower case to upper on output.*/ +0*OCRNL |/*Map CR to NL on output.*/ +0*ONOCR |/*No CR output at column 0.*/ +0*ONLRET |/*NL performs CR function.*/ +0*OFILL |/*Use fill characters for delay.*/ +0*OFDEL |/*Fill is DEL, else NULL.*/ +0*NL1 | +0*CR1 | +0*CR2 | +0*CR3 | +0*TAB1 | +0*TAB2 | +0*TAB3 |/*Expand tabs to spaces.*/ +0*BS1 | +0*VT1 | +0*FF1 | +#endif + + /* JALI: removed setting the tty_smode.c_cflag flags, since this is not */ + /* advisable if this is a *real* terminal, such as the console. In fact */ + /* this may hang the entire machine, deep, deep down (signalling break */ + /* or toggling the abort switch doesn't help) */ + + tty_smode.c_lflag = + 0; + +#if 0 +0*ISIG |/*Enable signals.*/ +0*ICANON |/*Canonical input (erase and kill processing).*/ +0*XCASE |/*Canonical upper/lower presentation.*/ +0*ECHO |/*Enable echo.*/ +0*ECHOE |/*Echo erase character as BS-SP-BS.*/ +0*ECHOK |/*Echo NL after kill character.*/ +0*ECHONL |/*Echo NL.*/ +0*NOFLSH |/*Disable flush after interrupt or quit.*/ +0*TOSTOP |/*Send SIGTTOU for background output.*/ +0*ECHOCTL|/*Echo control characters as ^char, delete as ^?.*/ +0*ECHOPRT|/*Echo erase character as character erased.*/ +0*ECHOKE |/*BS-SP-BS erase entire line on line kill.*/ +0*FLUSHO |/*Output is being flushed.*/ +0*PENDIN |/*Retype pending input at next read or input character.*/ +0*IEXTEN |/*Enable extended (implementation-defined) functions.*/ +#endif + + tty_smode.c_cc[VMIN] =0;/* Note that VMIN is the same as VEOF! */ + tty_smode.c_cc[VTIME] =0;/* Note that VTIME is the same as VEOL! */ + tty_smode.c_cc[VINTR] =3; + + tcsetattr(0, TCSADRAIN, &tty_smode); + +#ifdef DEBUG + show_terminal_settings(&tty_smode); +#endif + /* + * "Write a ^L to the FIFO which causes the other end to redisplay + * the input line." + * This does not seem to work as was intended in old comment above. + * However, this control character is now (R12B-3) used by run_erl + * to trigger the version handshaking between to_erl and run_erl + * at the start of every new to_erl-session. + */ + + if (write(wfd, "\014", 1) < 0) { + fprintf(stderr, "Error in writing ^L to FIFO.\n"); + } + + /* + * read and write + */ + while (1) { + FD_ZERO(&readfds); + FD_SET(0, &readfds); + FD_SET(rfd, &readfds); + if (select(rfd + 1, &readfds, NULL, NULL, NULL) < 0) { + if (recv_sig) { + FD_ZERO(&readfds); + } + else { + fprintf(stderr, "Error in select.\n"); + break; + } + } + len = 0; + + /* + * Read from terminal and write to FIFO + */ + if (recv_sig) { + switch (recv_sig) { + case SIGINT: + fprintf(stderr, "[Break]\n\r"); + buf[0] = '\003'; + len = 1; + break; + case SIGWINCH: + len = window_size_seq(buf,sizeof(buf)); + break; + default: + fprintf(stderr,"Unexpected signal: %u\n",recv_sig); + } + recv_sig = 0; + } + else if (FD_ISSET(0, &readfds)) { + len = read(0, buf, sizeof(buf)); + if (len <= 0) { + close(rfd); + close(wfd); + if (len < 0) { + fprintf(stderr, "Error in reading from stdin.\n"); + } else { + fprintf(stderr, "[EOF]\n\r"); + } + break; + } + /* check if there is an eof character in input */ + for (i = 0; i < len && buf[i] != tty_eof; i++); + if (buf[i] == tty_eof) { + fprintf(stderr, "[Quit]\n\r"); + break; + } + } + + if (len) { +#ifdef DEBUG + if(write(1, buf, len)); +#endif + if (write_all(wfd, buf, len) != len) { + fprintf(stderr, "Error in writing to FIFO.\n"); + close(rfd); + close(wfd); + break; + } + STATUS("\" OK\r\n"); + } + + /* + * Read from FIFO, write to terminal. + */ + if (FD_ISSET(rfd, &readfds)) { + STATUS("FIFO read: "); + len = read(rfd, buf, BUFSIZ); + if (len < 0 && errno == EAGAIN) { + /* + * No data this time, but the writing end of the FIFO is still open. + * Do nothing. + */ + ; + } else if (len <= 0) { + /* + * Either an error or end of file. In either case, break out + * of the loop. + */ + close(rfd); + close(wfd); + if (len < 0) { + fprintf(stderr, "Error in reading from FIFO.\n"); + } else + fprintf(stderr, "[End]\n\r"); + break; + } else { + if (!got_some) { + if ((len=version_handshake(buf,len,wfd)) < 0) { + close(rfd); + close(wfd); + break; + } + if (protocol_ver >= 1) { + /* Tell run_erl size of terminal window */ + signal(SIGWINCH, handle_sigwinch); + raise(SIGWINCH); + } + got_some = 1; + } + + /* + * We successfully read at least one character. Write what we got. + */ + STATUS("Terminal write: \""); + if (write_all(1, buf, len) != len) { + fprintf(stderr, "Error in writing to terminal.\n"); + close(rfd); + close(wfd); + break; + } + STATUS("\" OK\r\n"); + } + } + } + + /* + * Reset terminal characterstics + * XXX + */ + tcsetattr(0, TCSADRAIN, &tty_rmode); + return 0; +} + +/* Call write() until entire buffer has been written or error. + * Return len or -1. + */ +static int write_all(int fd, const char* buf, int len) +{ + int left = len; + int written; + while (left) { + written = write(fd,buf,left); + if (written < 0) { + return -1; + } + left -= written; + buf += written; + } + return len; +} + +static int window_size_seq(char* buf, size_t bufsz) +{ +#ifdef TIOCGWINSZ + struct winsize ws; + static const char prefix[] = "\033_"; + static const char suffix[] = "\033\\"; + /* This Esc sequence is called "Application Program Command" + and seems suitable to use for our own customized stuff. */ + + if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == 0) { + int len = sn_printf(buf, bufsz, "%swinsize=%u,%u%s", + prefix, ws.ws_col, ws.ws_row, suffix); + return len; + } +#endif /* TIOCGWINSZ */ + return 0; +} + +/* to_erl run_erl + * | | + * |---------- '\014' -------->| (session start) + * | | + * |<---- "[run_erl v1-0]" ----| (version interval) + * | | + * |--- Esc_"version=1"Esc\ -->| (common version) + * | | + */ +static int version_handshake(char* buf, int len, int wfd) +{ + unsigned re_high=0, re_low; + char *end = find_str(buf,len,"]\n"); + + if (end && sscanf(buf,"[run_erl v%u-%u",&re_high,&re_low)==2) { + char wbuf[30]; + int wlen; + + if (re_low > RUN_ERL_HI_VER || re_high < RUN_ERL_LO_VER) { + fprintf(stderr,"Incompatible versions: to_erl=v%u-%u run_erl=v%u-%u\n", + RUN_ERL_HI_VER, RUN_ERL_LO_VER, re_high, re_low); + return -1; + } + /* Choose highest common version */ + protocol_ver = re_high < RUN_ERL_HI_VER ? re_high : RUN_ERL_HI_VER; + + wlen = sn_printf(wbuf, sizeof(wbuf), "\033_version=%u\033\\", + protocol_ver); + if (write_all(wfd, wbuf, wlen) < 0) { + fprintf(stderr,"Failed to send version handshake\n"); + return -1; + } + end += 2; + len -= (end-buf); + memmove(buf,end,len); + + } + else { /* we assume old run_erl without version handshake */ + protocol_ver = 0; + } + + if (re_high != RUN_ERL_HI_VER) { + fprintf(stderr,"run_erl has different version, " + "using common protocol level %u\n", protocol_ver); + } + + return len; +} + -#include "to_erl_common.h" +#ifdef DEBUG +#define S(x) ((x) > 0 ? 1 : 0) -int main(int argc,char **argv) { - return to_erl(argc,argv); +static void show_terminal_settings(struct termios *t) +{ + fprintf(stderr,"c_iflag:\n"); + fprintf(stderr,"Signal interrupt on break: BRKINT %d\n", S(t->c_iflag & BRKINT)); + fprintf(stderr,"Map CR to NL on input: ICRNL %d\n", S(t->c_iflag & ICRNL)); + fprintf(stderr,"Ignore break condition: IGNBRK %d\n", S(t->c_iflag & IGNBRK)); + fprintf(stderr,"Ignore CR: IGNCR %d\n", S(t->c_iflag & IGNCR)); + fprintf(stderr,"Ignore char with par. err's: IGNPAR %d\n", S(t->c_iflag & IGNPAR)); + fprintf(stderr,"Map NL to CR on input: INLCR %d\n", S(t->c_iflag & INLCR)); + fprintf(stderr,"Enable input parity check: INPCK %d\n", S(t->c_iflag & INPCK)); + fprintf(stderr,"Strip character ISTRIP %d\n", S(t->c_iflag & ISTRIP)); + fprintf(stderr,"Enable start/stop input ctrl IXOFF %d\n", S(t->c_iflag & IXOFF)); + fprintf(stderr,"ditto output ctrl IXON %d\n", S(t->c_iflag & IXON)); + fprintf(stderr,"Mark parity errors PARMRK %d\n", S(t->c_iflag & PARMRK)); + fprintf(stderr,"\n"); + fprintf(stderr,"c_oflag:\n"); + fprintf(stderr,"Perform output processing OPOST %d\n", S(t->c_oflag & OPOST)); + fprintf(stderr,"\n"); + fprintf(stderr,"c_cflag:\n"); + fprintf(stderr,"Ignore modem status lines CLOCAL %d\n", S(t->c_cflag & CLOCAL)); + fprintf(stderr,"\n"); + fprintf(stderr,"c_local:\n"); + fprintf(stderr,"Enable echo ECHO %d\n", S(t->c_lflag & ECHO)); + fprintf(stderr,"\n"); + fprintf(stderr,"c_cc:\n"); + fprintf(stderr,"c_cc[VEOF] %d\n", t->c_cc[VEOF]); } +#endif |