Added logging flag to log_append() to change log behaviour

Valid flags are:

* LOGFL_NORMAL
Log all messages to the log context, and send log message to stderr
on errors

* LOGFL_NODUPS
Log only unique messages.  Duplicated messages will be removed

* LOGFL_NOSTDERR
Don't write to stderr, even if errors occur

8 files changed, 83 insertions, 65 deletions

diff --git a/src/dmidecode.c b/src/dmidecode.c
index 0fd8f1b..a29a743 100644
--- a/src/dmidecode.c
+++ b/src/dmidecode.c
@@ -4866,7 +4866,7 @@ static void dmi_table(Log_t *logp, int type, u32 base, u16 len, u16 num, u16 ver
         }
 
         if((buf = mem_chunk(logp, base, len, devmem)) == NULL) {
-                log_append(logp, LOG_WARNING, "Table is unreachable, sorry."
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING, "Table is unreachable, sorry."
 #ifndef USE_MMAP
                         "Try compiling dmidecode with -DUSE_MMAP."
 #endif
@@ -4889,8 +4889,9 @@ static void dmi_table(Log_t *logp, int type, u32 base, u16 len, u16 num, u16 ver
                  ** table is broken.
                  */
                 if(h.length < 4) {
-                        log_append(logp, LOG_WARNING, "Invalid entry length (%i). DMI table is broken! Stop.",
-                                (unsigned int)h.length);
+                        log_append(logp, LOGFL_NORMAL, LOG_WARNING,
+				   "Invalid entry length (%i). DMI table is broken! Stop.",
+				   (unsigned int)h.length);
                         break;
                 }
 
@@ -4955,10 +4956,10 @@ static void dmi_table(Log_t *logp, int type, u32 base, u16 len, u16 num, u16 ver
         }
 
         if(i != num)
-                log_append(logp, LOG_WARNING,
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING,
 			   "Wrong DMI structures count: %d announced, only %d decoded.\n", num, i);
         if(data - buf != len)
-		log_append(logp, LOG_WARNING,
+		log_append(logp, LOGFL_NODUPS, LOG_WARNING,
                         "Wrong DMI structures length: %d bytes announced, structures occupy %d bytes.\n",
                         len, (unsigned int)(data - buf));
 
diff --git a/src/dmidecodemodule.c b/src/dmidecodemodule.c
index 93a956b..dc00279 100644
--- a/src/dmidecodemodule.c
+++ b/src/dmidecodemodule.c
@@ -66,7 +66,8 @@ static void init(options *opt)
 
         /* sanity check */
         if(sizeof(u8) != 1 || sizeof(u16) != 2 || sizeof(u32) != 4 || '\0' != 0) {
-                log_append(opt->logdata, LOG_WARNING, "%s: compiler incompatibility\n", "dmidecodemodule");
+                log_append(opt->logdata, LOGFL_NORMAL, LOG_WARNING,
+                           "%s: compiler incompatibility\n", "dmidecodemodule");
         }
 }
 
@@ -78,11 +79,11 @@ int parse_opt_type(Log_t *logp, const char *arg)
 
                 val = strtoul(arg, &next, 0);
                 if(next == arg) {
-                        log_append(logp, LOG_ERR, "Invalid type keyword: %s\n", arg);
+                        log_append(logp, LOGFL_NODUPS, LOG_ERR, "Invalid type keyword: %s\n", arg);
                         return -1;
                 }
                 if(val > 0xff) {
-                        log_append(logp, LOG_ERR, "Invalid type number: %i\n", val);
+                        log_append(logp, LOGFL_NODUPS, LOG_ERR, "Invalid type number: %i\n", val);
                         return -1;
                 }
 
@@ -164,7 +165,8 @@ xmlNode *dmidecode_get_version(options *opt)
                 free(buf);
         }
         if( !found ) {
-                log_append(opt->logdata, LOG_WARNING, "No SMBIOS nor DMI entry point found, sorry.");
+                log_append(opt->logdata, LOGFL_NODUPS, LOG_WARNING,
+                           "No SMBIOS nor DMI entry point found, sorry.");
         }
         return ver_n;
 }
@@ -185,7 +187,8 @@ int dmidecode_get_xml(options *opt, xmlNode* dmixml_n)
 
         const char *f = opt->dumpfile ? opt->dumpfile : opt->devmem;
         if(access(f, R_OK) < 0) {
-                log_append(opt->logdata, LOG_WARNING, "Permission denied to memory file/device (%s)", f);
+                log_append(opt->logdata, LOGFL_NORMAL,
+                           LOG_WARNING, "Permission denied to memory file/device (%s)", f);
                 return 0;
         }
 
diff --git a/src/dmilog.c b/src/dmilog.c
index e9b89e8..f7ade5d 100644
--- a/src/dmilog.c
+++ b/src/dmilog.c
@@ -59,51 +59,56 @@ Log_t * log_init()
  * Registers a new log entry
  *
  * @param logp   Pointer to an allocated Log_t record.  New records will be appended to the end
+ * @param flags  Log flags, to specify logging behaviour
  * @param level  syslog log level values.  LOG_ERR and LOG_WARNING are allowed
  * @param fmt    stdarg based string with the log contents
  *
  * @return Returns 1 on successful registration of log entry, otherwise -1 and error is printed to stderr
+ *         unless LOGFL_NOSTDERR is set in flags.
  */
-int log_append(Log_t *logp, int level, const char *fmt, ...)
+int log_append(Log_t *logp, Log_f flags, int level, const char *fmt, ...)
 {
-	Log_t *ptr = NULL;
-	va_list ap;
-
-	// Go the end of the record chain
-	ptr = logp;
-	while( ptr && ptr->next ) {
-		ptr = ptr->next;
-	}
-
-
-	if( ptr && ((level == LOG_ERR) || (level == LOG_WARNING)) ) {
-		ptr->next = log_init();
-		if( ptr->next ) {
-			ptr->next->message = (char *) calloc(1, 4098);
-		}
-	}
+        Log_t *ptr = NULL;
+        va_list ap;
+        char logmsg[4098];
 
+        // Prepare log message
+        memset(&logmsg, 0, 4098);
         va_start(ap, fmt);
-	if( !ptr || !ptr->next || !ptr->next->message ) {
-		if( logp ) {
-			// Only print this if we logp is pointing somewhere.
-			// If it is NULL, the caller did not establish a log
-			// buffer on purpose (like dmidump.c) - thus this is
-			// not an error with saving the log entry.
-			fprintf(stderr, "** ERROR **  Failed to save log entry\n");
-		}
-                vfprintf(stderr, fmt, ap);
-                fprintf(stderr, "\n");
-		va_end(ap);
-		return -1;
-	}
-
-	ptr->next->level = level;
-	vsnprintf(ptr->next->message, 4096, fmt, ap);
-	ptr->next->message = realloc(ptr->next->message, strlen(ptr->next->message)+2);
-	va_end(ap);
-
-	return 1;
+        vsnprintf(logmsg, 4096, fmt, ap);
+        va_end(ap);
+
+        // Go the end of the record chain
+        ptr = logp;
+        while( ptr && ptr->next ) {
+                // Ignore duplicated messages if LOGFL_NODUPS is set
+                if( (flags & LOGFL_NODUPS) && ptr->next && ptr->next->message
+                    && (strcmp(ptr->next->message, logmsg) == 0) ) {
+                        return 1;
+                }
+                ptr = ptr->next;
+        }
+
+        if( ptr && ((level == LOG_ERR) || (level == LOG_WARNING)) ) {
+                ptr->next = log_init();
+                if( ptr->next ) {
+                        ptr->next->level = level;
+                        ptr->next->message = strdup(logmsg);
+                        return 1;
+                }
+        }
+
+        if( !(flags & LOGFL_NOSTDERR) ) {
+                if( logp ) {
+                        // Only print this if we logp is pointing somewhere.
+                        // If it is NULL, the caller did not establish a log
+                        // buffer on purpose (like dmidump.c) - thus this is
+                        // not an error with saving the log entry.
+                        fprintf(stderr, "** ERROR **  Failed to save log entry\n");
+                }
+                fprintf(stderr, "%s\n", logmsg);
+        }
+        return -1;
 }
 
 
diff --git a/src/dmilog.h b/src/dmilog.h
index 98d0780..76c87b6 100644
--- a/src/dmilog.h
+++ b/src/dmilog.h
@@ -46,8 +46,16 @@ struct _Log_t {
 };
 typedef struct _Log_t Log_t;
 
+/**
+ *  Log flags.  These flags can be OR'ed together
+ */
+typedef enum { LOGFL_NORMAL   = 1, /**< Normal behaviour, log everything and use stderr on errors */
+               LOGFL_NODUPS   = 2, /**< Don't log messages we already have logged */
+               LOGFL_NOSTDERR = 4  /**< Don't use stderr even if log functions fails */
+} Log_f;
+
 Log_t * log_init();
-int log_append(Log_t *logp, int level, const char *fmt, ...);
+int log_append(Log_t *logp, Log_f flags, int level, const char *fmt, ...);
 char * log_retrieve(Log_t *logp, int level);
 size_t log_clear_partial(Log_t *logp, int level, int unread);
 void log_close(Log_t *logp);
diff --git a/src/dmixml.c b/src/dmixml.c
index 6f1fd77..6f6aa60 100644
--- a/src/dmixml.c
+++ b/src/dmixml.c
@@ -352,9 +352,9 @@ char *dmixml_GetXPathContent(Log_t *logp, char *buf, size_t buflen, xmlXPathObje
                 break;
 
         default:
-                log_append(logp, LOG_WARNING, "dmixml_GetXPathContent(...):: "
-			   "Do not know how to handle XPath type %i\n",
-			   xpo->type);
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING, "dmixml_GetXPathContent(...):: "
+                           "Do not know how to handle XPath type %i\n",
+                           xpo->type);
                 return NULL;
         }
         return buf;
diff --git a/src/efi.c b/src/efi.c
index af0a813..171ae30 100644
--- a/src/efi.c
+++ b/src/efi.c
@@ -76,8 +76,9 @@ int address_from_efi(Log_t *logp, size_t * address)
         if(fclose(efi_systab) != 0)
                 perror(filename);
 
-        if(ret == EFI_NO_SMBIOS)
-                log_append(logp, LOG_WARNING, "%s: SMBIOS entry point missing\n", filename);
+        if(ret == EFI_NO_SMBIOS) {
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING, "%s: SMBIOS entry point missing\n", filename);
+        }
 
         return ret;
 }
diff --git a/src/util.c b/src/util.c
index ba1a89a..f0d9f93 100644
--- a/src/util.c
+++ b/src/util.c
@@ -69,7 +69,7 @@ static int myread(Log_t *logp, int fd, u8 * buf, size_t count, const char *prefi
 
         if(r2 != count) {
                 close(fd);
-                log_append(logp, LOG_WARNING, "%s: Unexpected end of file\n", prefix);
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING, "%s: Unexpected end of file\n", prefix);
                 return -1;
         }
 
@@ -102,12 +102,12 @@ void *mem_chunk(Log_t *logp, size_t base, size_t len, const char *devmem)
 #endif
 
         if((fd = open(devmem, O_RDONLY)) == -1) {
-		log_append(logp, LOG_WARNING, "%s: %s", devmem, strerror(errno));
+		log_append(logp, LOGFL_NORMAL, LOG_WARNING, "%s: %s", devmem, strerror(errno));
                 return NULL;
         }
 
         if((p = malloc(len)) == NULL) {
-		log_append(logp, LOG_WARNING, "malloc: %s", strerror(errno));
+		log_append(logp, LOGFL_NORMAL, LOG_WARNING, "malloc: %s", strerror(errno));
                 return NULL;
         }
 #ifdef USE_MMAP
@@ -123,7 +123,7 @@ void *mem_chunk(Log_t *logp, size_t base, size_t len, const char *devmem)
          */
         mmp = mmap(0, mmoffset + len, PROT_READ, MAP_SHARED, fd, base - mmoffset);
         if(mmp == MAP_FAILED) {
-                log_append(logp, LOG_WARNING, "%s (mmap): %s", devmem, strerror(errno));
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING, "%s (mmap): %s", devmem, strerror(errno));
                 free(p);
                 return NULL;
         }
@@ -131,11 +131,11 @@ void *mem_chunk(Log_t *logp, size_t base, size_t len, const char *devmem)
         memcpy(p, (u8 *) mmp + mmoffset, len);
 
         if(munmap(mmp, mmoffset + len) == -1) {
-                log_append(logp, LOG_WARNING, "%s (munmap): %s", devmem, strerror(errno));
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING, "%s (munmap): %s", devmem, strerror(errno));
         }
 #else /* USE_MMAP */
         if(lseek(fd, base, SEEK_SET) == -1) {
-                log_append(logp, LOG_WARNING, "%s (lseek): %s", devmem, strerror(errno));
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING, "%s (lseek): %s", devmem, strerror(errno));
                 free(p);
                 return NULL;
         }
diff --git a/src/xmlpythonizer.c b/src/xmlpythonizer.c
index 8596a9d..5342bac 100644
--- a/src/xmlpythonizer.c
+++ b/src/xmlpythonizer.c
@@ -304,7 +304,7 @@ inline ptzTYPES _convert_maptype(Log_t *logp, const char *str) {
         } else if( strcmp(str, "list:dict") == 0 ) {
                 return ptzLIST_DICT;
         } else {
-                log_append(logp, LOG_WARNING,
+                log_append(logp, LOGFL_NORMAL, LOG_WARNING,
 			   "Unknown field type: %s - defaulting to 'constant'\n", str);
                 return ptzCONST;
         }
@@ -463,7 +463,7 @@ ptzMAP *_dmimap_parse_mapping_node_typeid(Log_t *logp, xmlNode *mapnode, const c
         node = dmixml_FindNodeByAttr_NoCase(mapnode, "TypeMap", "id", typeid);
         if( node == NULL ) {
                 // No exception handling possible here, as we don't return PyObject
-                log_append(logp, LOG_WARNING, "** WARNING: Could not find any XML->Python "
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING, "** WARNING: Could not find any XML->Python "
 			   "mapping for type ID '%s'", typeid);
                 return NULL;
         }
@@ -665,7 +665,7 @@ inline PyObject *StringToPyObj(Log_t *logp, ptzMAP *val_m, const char *instr) {
                 break;
 
         default:
-                log_append(logp, LOG_WARNING,
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING,
 			   "Invalid type '%i' for value '%s'\n",
 			   val_m->type_value, instr);
                 value = Py_None;
@@ -737,7 +737,7 @@ char *_get_key_value(Log_t *logp, char *key, size_t buflen,
                 break;
 
         default:
-                log_append(logp, LOG_WARNING, "Unknown key type: %i\n", map_p->type_key);
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING, "Unknown key type: %i\n", map_p->type_key);
                 return NULL;
         }
         // We consider to have a key, if the first byte is a readable
@@ -999,7 +999,7 @@ PyObject *_deep_pythonize(Log_t *logp, PyObject *retdata,
                 break;
 
         default:
-                log_append(logp, LOG_WARNING, "Unknown value type: %i\n", map_p->type_value);
+                log_append(logp, LOGFL_NODUPS, LOG_WARNING, "Unknown value type: %i\n", map_p->type_value);
                 break;
         }
 
@@ -1070,7 +1070,7 @@ PyObject *pythonizeXMLnode(Log_t *logp, ptzMAP *in_map, xmlNode *data_n) {
                         }
 #ifdef DEBUG
                         else {
-                                log_append(logp, LOG_WARNING,
+                                log_append(logp, LOGFL_NODUPS, LOG_WARNING,
 					   "** pythonizeXMLnode :: Could not locate node for key value: "
 					   "root path '%s', key '%s'\n", map_p->rootpath, map_p->key);
                         }