erts: Refactor common parts out of run_erl and to_erl

This is in preperation for writing ose version of run_erl and to_erl

1 files changed, 610 insertions, 0 deletions

diff --git a/erts/etc/common/run_erl_common.c b/erts/etc/common/run_erl_common.c
new file mode 100644
index 0000000000..dc899c5349
--- /dev/null
+++ b/erts/etc/common/run_erl_common.c
@@ -0,0 +1,610 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#ifdef HAVE_SYSLOG_H
+#  include <syslog.h>
+#endif
+
+#include "run_erl_common.h"
+#include "safe_string.h"
+
+#define DEFAULT_LOG_GENERATIONS 5
+#define LOG_MAX_GENERATIONS     1000      /* No more than 1000 log files */
+#define LOG_MIN_GENERATIONS     2         /* At least two to switch between */
+#define DEFAULT_LOG_MAXSIZE     100000
+#define LOG_MIN_MAXSIZE         1000      /* Smallast value for changing log file */
+#define LOG_STUBNAME            "erlang.log."
+#define LOG_PERM                0664
+#define DEFAULT_LOG_ACTIVITY_MINUTES    5
+#define DEFAULT_LOG_ALIVE_MINUTES       15
+#define DEFAULT_LOG_ALIVE_FORMAT        "%a %b %e %T %Z %Y"
+#define ALIVE_BUFFSIZ                   1024
+
+#define STATUSFILENAME  "/run_erl.log"
+
+#define PIPE_STUBNAME   "erlang.pipe"
+#define PIPE_STUBLEN    strlen(PIPE_STUBNAME)
+#define PERM            (S_IWUSR | S_IRUSR | S_IWOTH | S_IROTH | S_IWGRP | S_IRGRP)
+
+#if !defined(O_SYNC)
+#define O_SYNC 0
+#define USE_FSYNC 1
+#endif
+
+/* prototypes */
+
+static int next_log(int log_num);
+static int prev_log(int log_num);
+static int find_next_log_num(void);
+static int open_log(int log_num, int flags);
+
+/* static data */
+static char statusfile[FILENAME_BUFSIZ];
+static char log_dir[FILENAME_BUFSIZ];
+static FILE *stdstatus = NULL;
+static int log_generations = DEFAULT_LOG_GENERATIONS;
+static int log_maxsize     = DEFAULT_LOG_MAXSIZE;
+static int log_activity_minutes = DEFAULT_LOG_ACTIVITY_MINUTES;
+static int log_alive_in_gmt = 0;
+static char log_alive_format[ALIVE_BUFFSIZ+1];
+static int run_daemon = 0;
+static unsigned protocol_ver = RUN_ERL_LO_VER; /* assume lowest to begin with */
+
+int erts_run_erl_log_alive_minutes = DEFAULT_LOG_ALIVE_MINUTES;
+
+/*
+ * Current log number and log fd
+ */
+static int log_num;
+static int lfd=0;
+
+
+/*
+ * getenv_int:
+ */
+static char *getenv_int(const char *name) {
+   return getenv(name);
+}
+
+/*
+ * next_log:
+ * Returns the index number that follows the given index number.
+ * (Wrapping after log_generations)
+ */
+static int next_log(int log_num) {
+  return log_num>=log_generations?1:log_num+1;
+}
+
+/*
+ * prev_log:
+ * Returns the index number that precedes the given index number.
+ * (Wrapping after log_generations)
+ */
+static int prev_log(int log_num) {
+  return log_num<=1?log_generations:log_num-1;
+}
+
+/*
+ * find_next_log_num()
+ * Searches through the log directory to check which logs that already
+ * exist. It finds the "hole" in the sequence, and returns the index
+ * number for the last log in the log sequence. If there is no hole, index
+ * 1 is returned.
+ */
+static int find_next_log_num(void) {
+  int i, next_gen, log_gen;
+  DIR *dirp;
+  struct dirent *direntp;
+  int log_exists[LOG_MAX_GENERATIONS+1];
+  int stub_len = strlen(LOG_STUBNAME);
+
+  /* Initialize exiting log table */
+
+  for(i=log_generations; i>=0; i--)
+    log_exists[i] = 0;
+  dirp = opendir(log_dir);
+  if(!dirp) {
+    ERRNO_ERR1(LOG_ERR,"Can't access log directory '%s'", log_dir);
+    exit(1);
+  }
+
+  /* Check the directory for existing logs */
+
+  while((direntp=readdir(dirp)) != NULL) {
+    if(strncmp(direntp->d_name,LOG_STUBNAME,stub_len)==0) {
+      int num = atoi(direntp->d_name+stub_len);
+      if(num < 1 || num > log_generations)
+	continue;
+      log_exists[num] = 1;
+    }
+  }
+  closedir(dirp);
+
+  /* Find out the next available log file number */
+
+  next_gen = 0;
+  for(i=log_generations; i>=0; i--) {
+    if(log_exists[i])
+      if(next_gen)
+	break;
+      else
+	;
+    else
+      next_gen = i;
+  }
+
+  /* Find out the current log file number */
+
+  if(next_gen)
+    log_gen = prev_log(next_gen);
+  else
+    log_gen = 1;
+
+  return log_gen;
+} /* find_next_log_num() */
+
+static int open_log(int log_num, int flags)
+{
+  char buf[FILENAME_MAX];
+  time_t now;
+  struct tm *tmptr;
+  char log_buffer[ALIVE_BUFFSIZ+1];
+
+  /* Remove the next log (to keep a "hole" in the log sequence) */
+  sn_printf(buf, sizeof(buf), "%s/%s%d",
+	    log_dir, LOG_STUBNAME, next_log(log_num));
+  unlink(buf);
+
+  /* Create or continue on the current log file */
+  sn_printf(buf, sizeof(buf), "%s/%s%d", log_dir, LOG_STUBNAME, log_num);
+
+  do {
+    lfd = open(buf, flags, LOG_PERM);
+  } while (lfd < 0 && errno == EINTR);
+
+  if(lfd <0){
+      ERRNO_ERR1(LOG_ERR,"Can't open log file '%s'.", buf);
+    exit(1);
+  }
+
+  /* Write a LOGGING STARTED and time stamp into the log file */
+  time(&now);
+  if (log_alive_in_gmt) {
+      tmptr = gmtime(&now);
+  } else {
+      tmptr = localtime(&now);
+  }
+  if (!strftime(log_buffer, ALIVE_BUFFSIZ, log_alive_format,
+		tmptr)) {
+      strn_cpy(log_buffer, sizeof(log_buffer),
+	      "(could not format time in 256 positions "
+	      "with current format string.)");
+  }
+  log_buffer[ALIVE_BUFFSIZ] = '\0';
+
+  sn_printf(buf, sizeof(buf), "\n=====\n===== LOGGING STARTED %s\n=====\n",
+	    log_buffer);
+  if (erts_run_erl_write_all(lfd, buf, strlen(buf)) < 0)
+      erts_run_erl_log_status("Error in writing to log.\n");
+
+#if USE_FSYNC
+  fsync(lfd);
+#endif
+
+  return lfd;
+}
+
+/* Instead of making sure basename exists, we do our own */
+char *simple_basename(char *path)
+{
+    char *ptr;
+    for (ptr = path; *ptr != '\0'; ++ptr) {
+	if (*ptr == '/') {
+	    path = ptr + 1;
+	}
+    }
+    return path;
+}
+
+ssize_t sf_read(int fd, void *buffer, size_t len) {
+    ssize_t n = 0;
+
+    do { n = read(fd, buffer, len); } while (n < 0 && errno == EINTR);
+
+    return n;
+}
+
+ssize_t sf_write(int fd, const void *buffer, size_t len) {
+    ssize_t n = 0;
+
+    do { n = write(fd, buffer, len); } while (n < 0 && errno == EINTR);
+
+    return n;
+}
+
+int sf_open(const char *path, int type, mode_t mode) {
+    int fd = 0;
+
+    do { fd = open(path, type, mode); } while(fd < 0 && errno == EINTR);
+
+    return fd;
+}
+
+int sf_close(int fd) {
+    int res = 0;
+
+    do { res = close(fd); } while(res < 0 && errno == EINTR);
+
+    return res;
+}
+
+/* Call write() until entire buffer has been written or error.
+ * Return len or -1.
+ */
+int erts_run_erl_write_all(int fd, const char* buf, int len)
+{
+    int left = len;
+    int written;
+    for (;;) {
+        do {
+	  written = write(fd,buf,left);
+	} while (written < 0 && errno == EINTR);
+	if (written == left) {
+	    return len;
+	}
+	if (written < 0) {
+	    return -1;
+	}
+	left -= written;
+	buf += written;
+    }
+    return written;
+}
+
+/* erts_run_erl_log_status()
+ * Prints the arguments to a status file
+ * Works like printf (see vfrpintf)
+ */
+void erts_run_erl_log_status(const char *format,...)
+{
+  va_list args;
+  time_t now;
+
+  if (stdstatus == NULL)
+    stdstatus = fopen(statusfile, "w");
+  if (stdstatus == NULL)
+    return;
+  now = time(NULL);
+  fprintf(stdstatus, "run_erl [%d] %s",
+	  (int)getpid(),
+	  ctime(&now));
+  va_start(args, format);
+  vfprintf(stdstatus, format, args);
+  va_end(args);
+  fflush(stdstatus);
+  return;
+}
+
+/* error_logf()
+ * Prints the arguments to stderr or syslog
+ * Works like printf (see vfprintf)
+ */
+void erts_run_erl_log_error(int priority, int line, const char *format, ...)
+{
+    va_list args;
+    va_start(args, format);
+
+#ifdef HAVE_SYSLOG_H
+    if (run_daemon) {
+	vsyslog(priority,format,args);
+    }
+    else
+#endif
+    {
+	time_t now = time(NULL);
+	fprintf(stderr, "run_erl:%d [%d] %s", line,
+		(int)getpid(),
+		ctime(&now));
+	vfprintf(stderr, format, args);
+    }
+    va_end(args);
+}
+
+/* erts_run_erl_log_write()
+ * Writes a message to lfd. If the current log file is full,
+ * a new log file is opened.
+ */
+int erts_run_erl_log_write(char* buf, size_t len)
+{
+  int size;
+  ssize_t res;
+  /* Decide if new logfile needed, and open if so */
+
+  size = lseek(lfd,0,SEEK_END);
+  if(size+len > log_maxsize) {
+    int res;
+    do {
+      res = close(lfd);
+    } while (res < 0 && errno == EINTR);
+    log_num = next_log(log_num);
+    lfd = open_log(log_num, O_RDWR|O_CREAT|O_TRUNC|O_SYNC);
+  }
+
+  /* Write to log file */
+
+  if ((res = erts_run_erl_write_all(lfd, buf, len)) < 0) {
+    erts_run_erl_log_status("Error in writing to log.\n");
+  }
+
+#if USE_FSYNC
+  fsync(lfd);
+#endif
+  return res;
+}
+
+int erts_run_erl_log_activity(int timeout,time_t now,time_t last_activity) {
+  char log_alive_buffer[ALIVE_BUFFSIZ+1];
+  char buf[BUFSIZ];
+
+  if (timeout || now - last_activity > log_activity_minutes*60) {
+    /* Either a time out: 15 minutes without action, */
+    /* or something is coming in right now, but it's a long time */
+    /* since last time, so let's write a time stamp this message */
+    struct tm *tmptr;
+    if (log_alive_in_gmt) {
+      tmptr = gmtime(&now);
+    } else {
+      tmptr = localtime(&now);
+    }
+    if (!strftime(log_alive_buffer, ALIVE_BUFFSIZ, log_alive_format,
+		  tmptr)) {
+      strn_cpy(log_alive_buffer, sizeof(log_alive_buffer),
+	       "(could not format time in 256 positions "
+	       "with current format string.)");
+    }
+    log_alive_buffer[ALIVE_BUFFSIZ] = '\0';
+
+    sn_printf(buf, sizeof(buf), "\n===== %s%s\n",
+	      timeout?"ALIVE ":"", log_alive_buffer);
+    return erts_run_erl_log_write(buf, strlen(buf));
+  }
+  return 0;
+}
+
+int erts_run_erl_log_open() {
+
+  log_num = find_next_log_num();
+  lfd = open_log(log_num, O_RDWR|O_APPEND|O_CREAT|O_SYNC);
+  return 0;
+}
+
+int erts_run_erl_log_init(int daemon, char* logdir) {
+  char *p;
+
+  /* Get values for LOG file handling from the environment */
+  if ((p = getenv_int("RUN_ERL_LOG_ALIVE_MINUTES"))) {
+      erts_run_erl_log_alive_minutes = atoi(p);
+      if (!erts_run_erl_log_alive_minutes) {
+	  ERROR1(LOG_ERR,"Minimum value for RUN_ERL_LOG_ALIVE_MINUTES is 1 "
+		 "(current value is %s)",p);
+      }
+      log_activity_minutes = erts_run_erl_log_alive_minutes / 3;
+      if (!log_activity_minutes) {
+	  ++log_activity_minutes;
+      }
+  }
+  if ((p = getenv_int(
+		   "RUN_ERL_LOG_ACTIVITY_MINUTES"))) {
+     log_activity_minutes = atoi(p);
+      if (!log_activity_minutes) {
+	  ERROR1(LOG_ERR,"Minimum value for RUN_ERL_LOG_ACTIVITY_MINUTES is 1 "
+		 "(current value is %s)",p);
+      }
+  }
+  if ((p = getenv_int("RUN_ERL_LOG_ALIVE_FORMAT"))) {
+      if (strlen(p) > ALIVE_BUFFSIZ) {
+	  ERROR1(LOG_ERR, "RUN_ERL_LOG_ALIVE_FORMAT can contain a maximum of "
+		 "%d characters", ALIVE_BUFFSIZ);
+      }
+      strn_cpy(log_alive_format, sizeof(log_alive_format), p);
+  } else {
+      strn_cpy(log_alive_format, sizeof(log_alive_format),
+	       DEFAULT_LOG_ALIVE_FORMAT);
+  }
+  if ((p = getenv_int("RUN_ERL_LOG_ALIVE_IN_UTC"))
+      && strcmp(p,"0")) {
+      ++log_alive_in_gmt;
+  }
+  if ((p = getenv_int("RUN_ERL_LOG_GENERATIONS"))) {
+    log_generations = atoi(p);
+    if (log_generations < LOG_MIN_GENERATIONS)
+      ERROR1(LOG_ERR,"Minimum RUN_ERL_LOG_GENERATIONS is %d",
+	     LOG_MIN_GENERATIONS);
+    if (log_generations > LOG_MAX_GENERATIONS)
+      ERROR1(LOG_ERR,"Maximum RUN_ERL_LOG_GENERATIONS is %d",
+	     LOG_MAX_GENERATIONS);
+  }
+
+  if ((p = getenv_int("RUN_ERL_LOG_MAXSIZE"))) {
+    log_maxsize = atoi(p);
+    if (log_maxsize < LOG_MIN_MAXSIZE)
+      ERROR1(LOG_ERR,"Minimum RUN_ERL_LOG_MAXSIZE is %d", LOG_MIN_MAXSIZE);
+  }
+
+  run_daemon = daemon;
+
+  strn_cpy(log_dir, sizeof(log_dir), logdir);
+  strn_cpy(statusfile, sizeof(statusfile), log_dir);
+  strn_cat(statusfile, sizeof(statusfile), STATUSFILENAME);
+
+  return 0;
+}
+
+/* create_fifo()
+ * Creates a new fifo with the given name and permission.
+ */
+static int create_fifo(char *name, int perm)
+{
+  if ((mkfifo(name, perm) < 0) && (errno != EEXIST))
+    return -1;
+  return 0;
+}
+
+/*
+ * w- and r_pipename have to be pre-allocated of atleast FILENAME_MAX size
+ */
+int erts_run_erl_open_fifo(char *pipename,char *w_pipename,char *r_pipename) {
+  int calculated_pipename = 0;
+  int highest_pipe_num = 0;
+  int fd;
+
+  /*
+   * Create FIFOs and open them
+   */
+
+  if(*pipename && pipename[strlen(pipename)-1] == '/') {
+    /* The user wishes us to find a unique pipe name in the specified */
+    /* directory */
+    DIR *dirp;
+    struct dirent *direntp;
+
+    calculated_pipename = 1;
+    dirp = opendir(pipename);
+    if(!dirp) {
+      ERRNO_ERR1(LOG_ERR,"Can't access pipe directory '%s'.", pipename);
+      return 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, BUFSIZ, "%s.%d",
+	      PIPE_STUBNAME, highest_pipe_num+1);
+  } /* if */
+
+  for(;;) {
+      /* write FIFO - is read FIFO for `to_erl' program */
+      strn_cpy(w_pipename, BUFSIZ, pipename);
+      strn_cat(w_pipename, BUFSIZ, ".r");
+      if (create_fifo(w_pipename, PERM) < 0) {
+	  ERRNO_ERR1(LOG_ERR,"Cannot create FIFO %s for writing.",
+		     w_pipename);
+	  return 1;
+      }
+
+      /* read FIFO - is write FIFO for `to_erl' program */
+      strn_cpy(r_pipename, BUFSIZ, pipename);
+      strn_cat(r_pipename, BUFSIZ, ".w");
+
+      /* Check that nobody is running run_erl already */
+      if ((fd = sf_open(r_pipename, O_WRONLY|DONT_BLOCK_PLEASE, 0)) >= 0) {
+	  /* Open as client succeeded -- run_erl is already running! */
+	  sf_close(fd);
+	  if (calculated_pipename) {
+	      ++highest_pipe_num;
+	      strn_catf(pipename, BUFSIZ, "%s.%d",
+			PIPE_STUBNAME, highest_pipe_num+1);
+	      continue;
+	  }
+	  fprintf(stderr, "Erlang already running on pipe %s.\n", pipename);
+	  return 1;
+      }
+      if (create_fifo(r_pipename, PERM) < 0) {
+	  ERRNO_ERR1(LOG_ERR,"Cannot create FIFO %s for reading.",
+		     r_pipename);
+	  return 1;
+      }
+      break;
+  }
+  return 0;
+}
+
+/* Extract any control sequences that are ment only for run_erl
+ * and should not be forwarded to the pty.
+ */
+int erts_run_erl_extract_ctrl_seq(char* buf, int len)
+{
+    static const char prefix[] = "\033_";
+    static const char suffix[] = "\033\\";
+    char* bufend = buf + len;
+    char* start = buf;
+    char* command;
+    char* end;
+
+    for (;;) {
+	start = find_str(start, bufend-start, prefix);
+	if (!start) break;
+
+	command = start + strlen(prefix);
+	end = find_str(command, bufend-command, suffix);
+	if (end) {
+	    unsigned col, row;
+	    if (sscanf(command,"version=%u", &PROTOCOL_VER)==1) {
+		/*fprintf(stderr,"to_erl v%u\n", protocol_ver);*/
+	    }
+	    else if (sscanf(command,"winsize=%u,%u", &col, &row)==2) {
+#ifdef TIOCSWINSZ
+	      struct winsize ws;
+	      ws.ws_col = col;
+	      ws.ws_row = row;
+	      if (ioctl(MFD, TIOCSWINSZ, &ws) < 0) {
+		ERRNO_ERR0(LOG_ERR,"Failed to set window size");
+	      }
+#endif
+	    }
+	    else {
+		ERROR2(LOG_ERR, "Ignoring unknown ctrl command '%.*s'\n",
+		       (int)(end-command), command);
+	    }
+
+	    /* Remove ctrl sequence from buf */
+	    end += strlen(suffix);
+	    memmove(start, end, bufend-end);
+	    bufend -= end - start;
+	}
+	else {
+	    ERROR2(LOG_ERR, "Missing suffix in ctrl sequence '%.*s'\n",
+		   (int)(bufend-start), start);
+	    break;
+	}
+    }
+    return bufend - buf;
+}