Initial support for multiple UIs

Move the device discovery code from separate udev helpers to a single
process to listen on two sockets: one SOCK_DGRAM for incoming udev
events, and one SOCK_STREAM for UIs to connect.

Initial support for client/server infrastructure, still need to wire-up
the udev messages.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 595 insertions, 0 deletions

diff --git a/discover/params.c b/discover/params.c
new file mode 100644
index 0000000..76a1451
--- /dev/null
+++ b/discover/params.c
@@ -0,0 +1,595 @@
+/* This modules is based on the params.c module from Samba, written by Karl Auer
+   and much modifed by Christopher Hertel. */
+
+/*
+ * 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 <stdlib.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include "params.h"
+
+#define new_array(type, num) ((type *)_new_array(sizeof(type), (num)))
+#define realloc_array(ptr, type, num) \
+	((type *)_realloc_array((ptr), sizeof(type), (num)))
+
+#define rprintf(x, ...) do { fprintf(stderr, ##__VA_ARGS__);	\
+				fprintf(stderr, "\n"); } while (0)
+#define rsyserr(x, y, ...) do { fprintf(stderr, ##__VA_ARGS__);	\
+				fprintf(stderr, "\n"); } while (0)
+
+#define MALLOC_MAX 0x40000000
+#define False 0
+#define True 1
+
+void *_new_array(unsigned int size, unsigned long num)
+{
+	if (num >= MALLOC_MAX/size)
+		return NULL;
+	return malloc(size * num);
+}
+
+void *_realloc_array(void *ptr, unsigned int size, unsigned long num)
+{
+	if (num >= MALLOC_MAX/size)
+		return NULL;
+	/* No realloc should need this, but just in case... */
+	if (!ptr)
+		return malloc(size * num);
+	return realloc(ptr, size * num);
+}
+
+
+/* -------------------------------------------------------------------------- **
+ *
+ * Module name: params
+ *
+ * -------------------------------------------------------------------------- **
+ *
+ *  This module performs lexical analysis and initial parsing of a
+ *  Windows-like parameter file.  It recognizes and handles four token
+ *  types:  section-name, parameter-name, parameter-value, and
+ *  end-of-file.  Comments and line continuation are handled
+ *  internally.
+ *
+ *  The entry point to the module is function pm_process().  This
+ *  function opens the source file, calls the Parse() function to parse
+ *  the input, and then closes the file when either the EOF is reached
+ *  or a fatal error is encountered.
+ *
+ *  A sample parameter file might look like this:
+ *
+ *  [section one]
+ *  parameter one = value string
+ *  parameter two = another value
+ *  [section two]
+ *  new parameter = some value or t'other
+ *
+ *  The parameter file is divided into sections by section headers:
+ *  section names enclosed in square brackets (eg. [section one]).
+ *  Each section contains parameter lines, each of which consist of a
+ *  parameter name and value delimited by an equal sign.  Roughly, the
+ *  syntax is:
+ *
+ *    <file>            :==  { <section> } EOF
+ *
+ *    <section>         :==  <section header> { <parameter line> }
+ *
+ *    <section header>  :==  '[' NAME ']'
+ *
+ *    <parameter line>  :==  NAME '=' VALUE '\n'
+ *
+ *  Blank lines and comment lines are ignored.  Comment lines are lines
+ *  beginning with either a semicolon (';') or a pound sign ('#').
+ *
+ *  All whitespace in section names and parameter names is compressed
+ *  to single spaces.  Leading and trailing whitespace is stipped from
+ *  both names and values.
+ *
+ *  Only the first equals sign in a parameter line is significant.
+ *  Parameter values may contain equals signs, square brackets and
+ *  semicolons.  Internal whitespace is retained in parameter values,
+ *  with the exception of the '\r' character, which is stripped for
+ *  historic reasons.  Parameter names may not start with a left square
+ *  bracket, an equal sign, a pound sign, or a semicolon, because these
+ *  are used to identify other tokens.
+ *
+ * -------------------------------------------------------------------------- **
+ */
+
+/* -------------------------------------------------------------------------- **
+ * Constants...
+ */
+
+#define BUFR_INC 1024
+
+
+/* -------------------------------------------------------------------------- **
+ * Variables...
+ *
+ *  bufr        - pointer to a global buffer.  This is probably a kludge,
+ *                but it was the nicest kludge I could think of (for now).
+ *  bSize       - The size of the global buffer <bufr>.
+ */
+
+static char *bufr  = NULL;
+static int   bSize = 0;
+
+/* -------------------------------------------------------------------------- **
+ * Functions...
+ */
+
+static int EatWhitespace( FILE *InFile )
+  /* ------------------------------------------------------------------------ **
+   * Scan past whitespace (see ctype(3C)) and return the first non-whitespace
+   * character, or newline, or EOF.
+   *
+   *  Input:  InFile  - Input source.
+   *
+   *  Output: The next non-whitespace character in the input stream.
+   *
+   *  Notes:  Because the config files use a line-oriented grammar, we
+   *          explicitly exclude the newline character from the list of
+   *          whitespace characters.
+   *        - Note that both EOF (-1) and the nul character ('\0') are
+   *          considered end-of-file markers.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int c;
+
+  for( c = getc( InFile ); isspace( c ) && ('\n' != c); c = getc( InFile ) )
+    ;
+  return( c );
+  } /* EatWhitespace */
+
+static int EatComment( FILE *InFile )
+  /* ------------------------------------------------------------------------ **
+   * Scan to the end of a comment.
+   *
+   *  Input:  InFile  - Input source.
+   *
+   *  Output: The character that marks the end of the comment.  Normally,
+   *          this will be a newline, but it *might* be an EOF.
+   *
+   *  Notes:  Because the config files use a line-oriented grammar, we
+   *          explicitly exclude the newline character from the list of
+   *          whitespace characters.
+   *        - Note that both EOF (-1) and the nul character ('\0') are
+   *          considered end-of-file markers.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int c;
+
+  for( c = getc( InFile ); ('\n'!=c) && (EOF!=c) && (c>0); c = getc( InFile ) )
+    ;
+  return( c );
+  } /* EatComment */
+
+static int Continuation( char *line, int pos )
+  /* ------------------------------------------------------------------------ **
+   * Scan backards within a string to discover if the last non-whitespace
+   * character is a line-continuation character ('\\').
+   *
+   *  Input:  line  - A pointer to a buffer containing the string to be
+   *                  scanned.
+   *          pos   - This is taken to be the offset of the end of the
+   *                  string.  This position is *not* scanned.
+   *
+   *  Output: The offset of the '\\' character if it was found, or -1 to
+   *          indicate that it was not.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  pos--;
+  while( (pos >= 0) && isspace(((unsigned char *)line)[pos]) )
+     pos--;
+
+  return( ((pos >= 0) && ('\\' == line[pos])) ? pos : -1 );
+  } /* Continuation */
+
+
+static BOOL Section( FILE *InFile, BOOL (*sfunc)(char *) )
+  /* ------------------------------------------------------------------------ **
+   * Scan a section name, and pass the name to function sfunc().
+   *
+   *  Input:  InFile  - Input source.
+   *          sfunc   - Pointer to the function to be called if the section
+   *                    name is successfully read.
+   *
+   *  Output: True if the section name was read and True was returned from
+   *          <sfunc>.  False if <sfunc> failed or if a lexical error was
+   *          encountered.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int   c;
+  int   i;
+  int   end;
+  char *func  = "params.c:Section() -";
+
+  i = 0;      /* <i> is the offset of the next free byte in bufr[] and  */
+  end = 0;    /* <end> is the current "end of string" offset.  In most  */
+              /* cases these will be the same, but if the last          */
+              /* character written to bufr[] is a space, then <end>     */
+              /* will be one less than <i>.                             */
+
+  c = EatWhitespace( InFile );    /* We've already got the '['.  Scan */
+                                  /* past initial white space.        */
+
+  while( (EOF != c) && (c > 0) )
+    {
+
+    /* Check that the buffer is big enough for the next character. */
+    if( i > (bSize - 2) )
+      {
+      bSize += BUFR_INC;
+      bufr   = realloc_array( bufr, char, bSize );
+      if( NULL == bufr )
+        {
+        rprintf(FERROR, "%s Memory re-allocation failure.", func);
+        return( False );
+        }
+      }
+
+    /* Handle a single character. */
+    switch( c )
+      {
+      case ']':                       /* Found the closing bracket.         */
+        bufr[end] = '\0';
+        if( 0 == end )                  /* Don't allow an empty name.       */
+          {
+          rprintf(FERROR, "%s Empty section name in configuration file.\n", func );
+          return( False );
+          }
+        if( !sfunc( bufr ) )            /* Got a valid name.  Deal with it. */
+          return( False );
+        (void)EatComment( InFile );     /* Finish off the line.             */
+        return( True );
+
+      case '\n':                      /* Got newline before closing ']'.    */
+        i = Continuation( bufr, i );    /* Check for line continuation.     */
+        if( i < 0 )
+          {
+          bufr[end] = '\0';
+          rprintf(FERROR, "%s Badly formed line in configuration file: %s\n",
+                   func, bufr );
+          return( False );
+          }
+        end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
+        c = getc( InFile );             /* Continue with next line.         */
+        break;
+
+      default:                        /* All else are a valid name chars.   */
+        if( isspace( c ) )              /* One space per whitespace region. */
+          {
+          bufr[end] = ' ';
+          i = end + 1;
+          c = EatWhitespace( InFile );
+          }
+        else                            /* All others copy verbatim.        */
+          {
+          bufr[i++] = c;
+          end = i;
+          c = getc( InFile );
+          }
+      }
+    }
+
+  /* We arrive here if we've met the EOF before the closing bracket. */
+  rprintf(FERROR, "%s Unexpected EOF in the configuration file: %s\n", func, bufr );
+  return( False );
+  } /* Section */
+
+static BOOL Parameter( FILE *InFile, BOOL (*pfunc)(char *, char *), int c )
+  /* ------------------------------------------------------------------------ **
+   * Scan a parameter name and value, and pass these two fields to pfunc().
+   *
+   *  Input:  InFile  - The input source.
+   *          pfunc   - A pointer to the function that will be called to
+   *                    process the parameter, once it has been scanned.
+   *          c       - The first character of the parameter name, which
+   *                    would have been read by Parse().  Unlike a comment
+   *                    line or a section header, there is no lead-in
+   *                    character that can be discarded.
+   *
+   *  Output: True if the parameter name and value were scanned and processed
+   *          successfully, else False.
+   *
+   *  Notes:  This function is in two parts.  The first loop scans the
+   *          parameter name.  Internal whitespace is compressed, and an
+   *          equal sign (=) terminates the token.  Leading and trailing
+   *          whitespace is discarded.  The second loop scans the parameter
+   *          value.  When both have been successfully identified, they are
+   *          passed to pfunc() for processing.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int   i       = 0;    /* Position within bufr. */
+  int   end     = 0;    /* bufr[end] is current end-of-string. */
+  int   vstart  = 0;    /* Starting position of the parameter value. */
+  char *func    = "params.c:Parameter() -";
+
+  /* Read the parameter name. */
+  while( 0 == vstart )  /* Loop until we've found the start of the value. */
+    {
+
+    if( i > (bSize - 2) )       /* Ensure there's space for next char.    */
+      {
+      bSize += BUFR_INC;
+      bufr   = realloc_array( bufr, char, bSize );
+      if( NULL == bufr )
+        {
+        rprintf(FERROR, "%s Memory re-allocation failure.", func) ;
+        return( False );
+        }
+      }
+
+    switch( c )
+      {
+      case '=':                 /* Equal sign marks end of param name. */
+        if( 0 == end )              /* Don't allow an empty name.      */
+          {
+          rprintf(FERROR, "%s Invalid parameter name in config. file.\n", func );
+          return( False );
+          }
+        bufr[end++] = '\0';         /* Mark end of string & advance.   */
+        i       = end;              /* New string starts here.         */
+        vstart  = end;              /* New string is parameter value.  */
+        bufr[i] = '\0';             /* New string is nul, for now.     */
+        break;
+
+      case '\n':                /* Find continuation char, else error. */
+        i = Continuation( bufr, i );
+        if( i < 0 )
+          {
+          bufr[end] = '\0';
+          rprintf(FERROR, "%s Ignoring badly formed line in configuration file: %s\n",
+                   func, bufr );
+          return( True );
+          }
+        end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
+        c = getc( InFile );       /* Read past eoln.                   */
+        break;
+
+      case '\0':                /* Shouldn't have EOF within param name. */
+      case EOF:
+        bufr[i] = '\0';
+        rprintf(FERROR, "%s Unexpected end-of-file at: %s\n", func, bufr );
+        return( True );
+
+      default:
+        if( isspace( c ) )     /* One ' ' per whitespace region.       */
+          {
+          bufr[end] = ' ';
+          i = end + 1;
+          c = EatWhitespace( InFile );
+          }
+        else                   /* All others verbatim.                 */
+          {
+          bufr[i++] = c;
+          end = i;
+          c = getc( InFile );
+          }
+      }
+    }
+
+  /* Now parse the value. */
+  c = EatWhitespace( InFile );  /* Again, trim leading whitespace. */
+  while( (EOF !=c) && (c > 0) )
+    {
+
+    if( i > (bSize - 2) )       /* Make sure there's enough room. */
+      {
+      bSize += BUFR_INC;
+      bufr   = realloc_array( bufr, char, bSize );
+      if( NULL == bufr )
+        {
+        rprintf(FERROR, "%s Memory re-allocation failure.", func) ;
+        return( False );
+        }
+      }
+
+    switch( c )
+      {
+      case '\r':              /* Explicitly remove '\r' because the older */
+        c = getc( InFile );   /* version called fgets_slash() which also  */
+        break;                /* removes them.                            */
+
+      case '\n':              /* Marks end of value unless there's a '\'. */
+        i = Continuation( bufr, i );
+        if( i < 0 )
+          c = 0;
+        else
+          {
+          for( end = i; (end >= 0) && isspace(((unsigned char *) bufr)[end]); end-- )
+            ;
+          c = getc( InFile );
+          }
+        break;
+
+      default:               /* All others verbatim.  Note that spaces do */
+        bufr[i++] = c;       /* not advance <end>.  This allows trimming  */
+        if( !isspace( c ) )  /* of whitespace at the end of the line.     */
+          end = i;
+        c = getc( InFile );
+        break;
+      }
+    }
+  bufr[end] = '\0';          /* End of value. */
+
+  return( pfunc( bufr, &bufr[vstart] ) );   /* Pass name & value to pfunc().  */
+  } /* Parameter */
+
+static BOOL Parse( FILE *InFile,
+                   BOOL (*sfunc)(char *),
+                   BOOL (*pfunc)(char *, char *) )
+  /* ------------------------------------------------------------------------ **
+   * Scan & parse the input.
+   *
+   *  Input:  InFile  - Input source.
+   *          sfunc   - Function to be called when a section name is scanned.
+   *                    See Section().
+   *          pfunc   - Function to be called when a parameter is scanned.
+   *                    See Parameter().
+   *
+   *  Output: True if the file was successfully scanned, else False.
+   *
+   *  Notes:  The input can be viewed in terms of 'lines'.  There are four
+   *          types of lines:
+   *            Blank      - May contain whitespace, otherwise empty.
+   *            Comment    - First non-whitespace character is a ';' or '#'.
+   *                         The remainder of the line is ignored.
+   *            Section    - First non-whitespace character is a '['.
+   *            Parameter  - The default case.
+   * 
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int    c;
+
+  c = EatWhitespace( InFile );
+  while( (EOF != c) && (c > 0) )
+    {
+    switch( c )
+      {
+      case '\n':                        /* Blank line. */
+        c = EatWhitespace( InFile );
+        break;
+
+      case ';':                         /* Comment line. */
+      case '#':
+        c = EatComment( InFile );
+        break;
+
+      case '[':                         /* Section Header. */
+	      if (!sfunc) return True;
+	      if( !Section( InFile, sfunc ) )
+		      return( False );
+	      c = EatWhitespace( InFile );
+	      break;
+
+      case '\\':                        /* Bogus backslash. */
+        c = EatWhitespace( InFile );
+        break;
+
+      default:                          /* Parameter line. */
+        if( !Parameter( InFile, pfunc, c ) )
+          return( False );
+        c = EatWhitespace( InFile );
+        break;
+      }
+    }
+  return( True );
+  } /* Parse */
+
+static FILE *OpenConfFile( char *FileName )
+  /* ------------------------------------------------------------------------ **
+   * Open a configuration file.
+   *
+   *  Input:  FileName  - The pathname of the config file to be opened.
+   *
+   *  Output: A pointer of type (FILE *) to the opened file, or NULL if the
+   *          file could not be opened.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  FILE *OpenedFile;
+  char *func = "params.c:OpenConfFile() -";
+
+  if( NULL == FileName || 0 == *FileName )
+    {
+    rprintf(FERROR,"%s No configuration filename specified.\n", func);
+    return( NULL );
+    }
+
+  OpenedFile = fopen( FileName, "r" );
+  if( NULL == OpenedFile )
+    {
+    rsyserr(FERROR, errno, "unable to open configuration file \"%s\"",
+	    FileName);
+    }
+
+  return( OpenedFile );
+  } /* OpenConfFile */
+
+BOOL pm_process( char *FileName,
+                 BOOL (*sfunc)(char *),
+                 BOOL (*pfunc)(char *, char *) )
+  /* ------------------------------------------------------------------------ **
+   * Process the named parameter file.
+   *
+   *  Input:  FileName  - The pathname of the parameter file to be opened.
+   *          sfunc     - A pointer to a function that will be called when
+   *                      a section name is discovered.
+   *          pfunc     - A pointer to a function that will be called when
+   *                      a parameter name and value are discovered.
+   *
+   *  Output: TRUE if the file was successfully parsed, else FALSE.
+   *
+   * ------------------------------------------------------------------------ **
+   */
+  {
+  int   result;
+  FILE *InFile;
+  char *func = "params.c:pm_process() -";
+
+  InFile = OpenConfFile( FileName );          /* Open the config file. */
+  if( NULL == InFile )
+    return( False );
+
+  if( NULL != bufr )                          /* If we already have a buffer */
+    result = Parse( InFile, sfunc, pfunc );   /* (recursive call), then just */
+                                              /* use it.                     */
+
+  else                                        /* If we don't have a buffer   */
+    {                                         /* allocate one, then parse,   */
+    bSize = BUFR_INC;                         /* then free.                  */
+    bufr = new_array( char, bSize );
+    if( NULL == bufr )
+      {
+      rprintf(FERROR,"%s memory allocation failure.\n", func);
+      fclose(InFile);
+      return( False );
+      }
+    result = Parse( InFile, sfunc, pfunc );
+    free( bufr );
+    bufr  = NULL;
+    bSize = 0;
+    }
+
+  fclose(InFile);
+
+  if( !result )                               /* Generic failure. */
+    {
+    rprintf(FERROR,"%s Failed.  Error returned from params.c:parse().\n", func);
+    return( False );
+    }
+
+  return( True );                             /* Generic success. */
+  } /* pm_process */
+
+/* -------------------------------------------------------------------------- */
+