Import code to load configuration from file.

WARNING: This commit do not contains a fully cleaned code:
 - Only nfc-list have been tested
 - Some -commented- code is not used ATM
 - Some printf-as-debug remain in this commit
... but that a bit usable so... happy hacking ;-)

include/nfc/nfc.h

@@ -63,7 +63,7 @@ extern  "C" {
 #  endif                        // __cplusplus
 
   /* Library initialization/deinitialization */
-  NFC_EXPORT void nfc_init(nfc_context *context);
+  NFC_EXPORT void nfc_init(nfc_context **context);
   NFC_EXPORT void nfc_exit(nfc_context *context);
 
   /* NFC Device/Hardware manipulation */

libnfc.conf.sample

@@ -0,0 +1,8 @@
+# Allow device auto-detection (default: true)
+# Note: if this auto-detection is disable, user have to set manually a device
+# configuration using file or environnement variable
+#allow_autoscan = true
+
+# Allow intrusive auto-detection (default: false)
+# Warning: intrusive auto-detection can seriously disturb other devices
+#allow_intrusive_autoscan = false

libnfc/Makefile.am

@@ -4,6 +4,7 @@ SUBDIRS = chips buses drivers .
 AM_CPPFLAGS = $(all_includes) $(LIBNFC_CFLAGS)
 
 noinst_HEADERS = \
+		 conf.h \
 		 drivers.h \
 		 iso7816.h \
 		 log.h \
@@ -13,6 +14,7 @@ noinst_HEADERS = \
 
 lib_LTLIBRARIES = libnfc.la
 libnfc_la_SOURCES = \
+		    conf.c \
 		    iso14443-subr.c \
 		    mirror-subr.c \
 		    nfc.c \

libnfc/conf.c

@@ -0,0 +1,131 @@
+/*-
+ * Copyright (C) 2012 Romuald Conty
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 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 Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <regex.h>
+#include <sys/stat.h>
+
+#include <nfc/nfc.h>
+#include "nfc-internal.h"
+#include "log.h"
+
+#define LOG_CATEGORY "libnfc.config"
+
+#define LIBNFC_SYSCONFDIR      "/etc/nfc"
+#define LIBNFC_CONFFILE        LIBNFC_SYSCONFDIR"/libnfc.conf"
+#define LIBNFC_DEVICECONFDIR   LIBNFC_SYSCONFDIR"/devices.d"
+
+
+bool conf_parse_file(const char* filename, void (*conf_keyvalue)(void* data, const char* key, const char* value), void* data)
+{
+  FILE *f = fopen (filename, "r");
+  if (!f) {
+    perror ("fopen");
+    return false;
+  }
+  char line[BUFSIZ];
+  const char *str_regex = "^[[:space:]]*([[:alnum:]_]+)[[:space:]]*=[[:space:]]*(\"(.+)\"|([^[:space:]]+))[[:space:]]*$";
+  regex_t preg;
+  if(regcomp (&preg, str_regex, REG_EXTENDED|REG_NOTEOL) != 0) {
+    printf ("regcomp error\n");
+    return false;
+  }
+  size_t nmatch = preg.re_nsub + 1;
+  regmatch_t *pmatch = malloc (sizeof (*pmatch) * nmatch);
+  if(!pmatch) {
+    perror ("malloc");
+    return false;
+  }
+
+  int lineno = 0;
+  while (fgets(line, BUFSIZ, f) != NULL) {
+    lineno++;
+    switch(line[0]) {
+      case '#':
+      case '\n':
+        break;
+      default: {
+        int match;
+        if ((match = regexec (&preg, line, nmatch, pmatch, 0)) == 0) {
+          const size_t key_size = pmatch[1].rm_eo - pmatch[1].rm_so;
+          const off_t  value_pmatch = pmatch[3].rm_eo!=-1?3:4;
+          const size_t value_size = pmatch[value_pmatch].rm_eo - pmatch[value_pmatch].rm_so;
+          char key[key_size+1];
+          char value[value_size+1];
+          strncpy(key, line+(pmatch[1].rm_so), key_size); key[key_size]='\0';
+          strncpy(value, line+(pmatch[value_pmatch].rm_so), value_size); value[value_size]='\0';
+          conf_keyvalue(data, key, value);
+        } else {
+          log_put( LOG_CATEGORY, NFC_PRIORITY_TRACE, "parse error on line #%d: %s", lineno, line);
+        }
+      }
+      break;
+    }
+  }
+  return false;
+}
+
+void 
+conf_keyvalue_context(void *data, const char* key, const char* value)
+{
+  nfc_context *context = (nfc_context*)data;
+  printf ("key: [%s], value: [%s]\n", key, value);
+  if (strcmp(key, "allow_autoscan") == 0) {
+    string_as_boolean(value, &(context->allow_autoscan));
+  } else if (strcmp(key, "allow_intrusive_scan") == 0) {
+    string_as_boolean(value, &(context->allow_intrusive_scan));
+  } else {
+    log_put( LOG_CATEGORY, NFC_PRIORITY_INFO, "unknown key in config line: %s = %s", key, value);
+  }
+}
+
+void 
+conf_load(nfc_context *context)
+{
+  conf_parse_file(LIBNFC_CONFFILE, conf_keyvalue_context, context);
+}
+
+/*
+int 
+main(int argc, char *argv[])
+{
+  DIR *d = opendir(LIBNFC_DEVICECONFDIR);
+  if (!d) {
+    perror ("opendir");
+  } else {
+    struct dirent* de;
+    while (de = readdir(d)) {
+      if (de->d_name[0]!='.') {
+        printf ("\t%s\n", de->d_name);
+        char filename[BUFSIZ] = LIBNFC_DEVICECONFDIR"/";
+        strcat (filename, de->d_name);
+        struct stat s;
+        if (stat(filename, &s) == -1) {
+          perror("stat");
+          continue;
+        }
+        if(S_ISREG(s.st_mode)) {
+          nfc_open_from_file (filename);
+        }
+      }
+    }
+  }
+}
+*/

libnfc/conf.h

@@ -0,0 +1,19 @@
+/*-
+ * Copyright (C) 2012 Romuald Conty
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 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 Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+void conf_load(nfc_context *context);
+

libnfc/nfc-internal.c

@@ -24,20 +24,31 @@
 
 #include <nfc/nfc.h>
 #include "nfc-internal.h"
+#include "conf.h"
 
 #include <stdlib.h>
 #include <string.h>
 
-static bool
+void 
-string_as_boolean(const char* s)
+string_as_boolean(const char* s, bool *value)
 {
-  if ((s) && (
+  if (s) {
-    (strcmp(s, "yes") == 0) ||
+    if (!(*value)) {
+      if ( (strcmp(s, "yes") == 0) ||
            (strcmp(s, "true") == 0) ||
-    (strcmp(s, "1") == 0))) {
+           (strcmp(s, "1") == 0) ) {
-    return true;
+           *value = true;
+           return;
+      }
+    } else {
+      if ( (strcmp(s, "no") == 0) ||
+           (strcmp(s, "false") == 0) ||
+           (strcmp(s, "0") == 0) ) {
+           *value = false;
+           return;
+      }
+    }
   }
-  return false;
 }
 
 nfc_context *
@@ -49,10 +60,20 @@ nfc_context_new(void)
     err(EXIT_FAILURE, "nfc_context_new: malloc");
   }
 
+  // Set default context values
+  res->allow_autoscan = true;
+  res->allow_intrusive_scan = false;
+
+  // Load options from configuration file (ie. /etc/nfc/libnfc.conf)
+  conf_load(res);
+
+  // Environment variables
   // Load "intrusive scan" option
-  // XXX: Load this option from configuration file too ?
   char *envvar = getenv("LIBNFC_INTRUSIVE_SCAN");
-  res->allow_intrusive_scan = string_as_boolean(envvar);
+  string_as_boolean(envvar, &(res->allow_intrusive_scan));
+
+  // Debug context state
+  log_put ("libnfc", NFC_PRIORITY_DEBUG, "allow_autoscan is set to %s", (res->allow_autoscan)?"true":"false");
   log_put ("libnfc", NFC_PRIORITY_DEBUG, "allow_intrusive_scan is set to %s", (res->allow_intrusive_scan)?"true":"false");
   return res;
 }

libnfc/nfc-internal.h

@@ -158,6 +158,7 @@ struct nfc_driver {
  * Struct which contains internal options, references, pointers, etc. used by library
  */
 struct nfc_context {
+  bool allow_autoscan;
   bool allow_intrusive_scan;
 };
 
@@ -195,6 +196,8 @@ struct nfc_device {
 nfc_device *nfc_device_new(const nfc_connstring connstring);
 void        nfc_device_free(nfc_device *dev);
 
+void string_as_boolean(const char* s, bool *value);
+
 void iso14443_cascade_uid(const uint8_t abtUID[], const size_t szUID, uint8_t *pbtCascadedUID, size_t *pszCascadedUID);
 
 void prepare_initiator_data(const nfc_modulation nm, uint8_t **ppbtInitiatorData, size_t *pszInitiatorData);

libnfc/nfc.c

@@ -108,12 +108,16 @@ const struct nfc_driver *nfc_drivers[] = {
 /** @ingroup lib
  * @brief Initialize libnfc.
  * This function must be called before calling any other libnfc function
- * @param context Optional output location for context pointer
+ * @param context Output location for nfc_context
  */
 void
-nfc_init(nfc_context *context)
+nfc_init(nfc_context **context)
 {
-  (void) context;
+  if (!context) {
+    printf("Error: NULL context is not supported anymore, please fix your code.\n");
+    exit(EXIT_FAILURE);
+  }
+  *context = nfc_context_new();
   log_init();
 }
 
@@ -265,9 +269,14 @@ nfc_list_devices(nfc_context *context, nfc_connstring connstrings[], const size_
   const struct nfc_driver *ndr;
   const struct nfc_driver **pndr = nfc_drivers;
 
-  if (!context) context = nfc_context_new(); // Should we support NULL context ?
+  if (!context) {
-  // FIXME: Load device(s) from configuration file(s)
+    printf ("NULL context is not supported anymore! Please fix your code.");
+  }
 
+  // TODO Load manually configured devices (from config file and env variables)
+
+  // Device auto-detection
+  if (context->allow_autoscan) {
     while ((ndr = *pndr)) {
       size_t _device_found = 0;
       if((ndr->scan_type == NOT_INTRUSIVE) || ((context->allow_intrusive_scan) && (ndr->scan_type == INTRUSIVE))) {
@@ -281,7 +290,8 @@ nfc_list_devices(nfc_context *context, nfc_connstring connstrings[], const size_
       } // scan_type is INTRUSIVE but not allowed or NOT_AVAILABLE
       pndr++;
     }
-  log_fini();
+  }
+
   return device_found;
 }
 

utils/nfc-list.c

@@ -75,7 +75,8 @@ main(int argc, const char *argv[])
   bool verbose = false;
   int res = 0;
 
-  nfc_init(NULL);
+  nfc_context *context;
+  nfc_init(&context);
 
   // Display libnfc version
   acLibnfcVersion = nfc_version();
@@ -97,7 +98,7 @@ main(int argc, const char *argv[])
 
   /* Lazy way to open an NFC device */
 #if 0
-  pnd = nfc_open(NULL, NULL);
+  pnd = nfc_open(context, NULL);
 #endif
 
   /* If specific device is wanted, i.e. an ARYGON device on /dev/ttyUSB0 */
@@ -106,7 +107,7 @@ main(int argc, const char *argv[])
   ndd.pcDriver = "ARYGON";
   ndd.pcPort = "/dev/ttyUSB0";
   ndd.uiSpeed = 115200;
-  pnd = nfc_open(NULL, &ndd);
+  pnd = nfc_open(context, &ndd);
 #endif
 
   /* If specific device is wanted, i.e. a SCL3711 on USB */
@@ -114,10 +115,10 @@ main(int argc, const char *argv[])
   nfc_device_desc_t ndd;
   ndd.pcDriver = "PN533_USB";
   strcpy(ndd.acDevice, "SCM Micro / SCL3711-NFC&RW");
-  pnd = nfc_open(NULL, &ndd);
+  pnd = nfc_open(context, &ndd);
 #endif
   nfc_connstring connstrings[MAX_DEVICE_COUNT];
-  size_t szDeviceFound = nfc_list_devices(NULL, connstrings, MAX_DEVICE_COUNT);
+  size_t szDeviceFound = nfc_list_devices(context, connstrings, MAX_DEVICE_COUNT);
 
   if (szDeviceFound == 0) {
     printf("No NFC device found.\n");
@@ -125,7 +126,7 @@ main(int argc, const char *argv[])
 
   for (i = 0; i < szDeviceFound; i++) {
     nfc_target ant[MAX_TARGET_COUNT];
-    pnd = nfc_open(NULL, connstrings[i]);
+    pnd = nfc_open(context, connstrings[i]);
 
     if (pnd == NULL) {
       ERR("Unable to open NFC device: %s", connstrings[i]);