mbed_trace.c

00001 /*
00002  * Copyright (c) 2014-2015 ARM Limited. All rights reserved.
00003  * SPDX-License-Identifier: Apache-2.0
00004  * Licensed under the Apache License, Version 2.0 (the License); you may
00005  * not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  * http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00012  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include <stdio.h>
00017 #include <string.h>
00018 #include <stdarg.h>
00019 
00020 #ifdef MBED_CONF_MBED_TRACE_ENABLE
00021 #undef MBED_CONF_MBED_TRACE_ENABLE
00022 #endif
00023 #define MBED_CONF_MBED_TRACE_ENABLE 1
00024 #ifndef MBED_CONF_MBED_TRACE_FEA_IPV6
00025 #define MBED_CONF_MBED_TRACE_FEA_IPV6 1
00026 #endif
00027 
00028 #include "mbed-trace/mbed_trace.h"
00029 #if MBED_CONF_MBED_TRACE_FEA_IPV6 == 1
00030 #include "mbed-client-libservice/ip6string.h"
00031 #include "mbed-client-libservice/common_functions.h"
00032 #endif
00033 
00034 #if defined(YOTTA_CFG_MBED_TRACE_MEM)
00035 #define MBED_TRACE_MEM_INCLUDE      YOTTA_CFG_MBED_TRACE_MEM_INCLUDE
00036 #define MBED_TRACE_MEM_ALLOC        YOTTA_CFG_MBED_TRACE_MEM_ALLOC
00037 #define MBED_TRACE_MEM_FREE         YOTTA_CFG_MBED_TRACE_MEM_FREE
00038 #else /* YOTTA_CFG_MEMLIB */
00039 // Default options
00040 #ifndef MBED_TRACE_MEM_INCLUDE
00041 #define MBED_TRACE_MEM_INCLUDE   <stdlib.h>
00042 #endif
00043 #include MBED_TRACE_MEM_INCLUDE
00044 #ifndef MBED_TRACE_MEM_ALLOC
00045 #define MBED_TRACE_MEM_ALLOC malloc
00046 #endif
00047 #ifndef MBED_TRACE_MEM_FREE
00048 #define MBED_TRACE_MEM_FREE  free
00049 #endif
00050 #endif /* YOTTA_CFG_MEMLIB */
00051 
00052 #define VT100_COLOR_ERROR "\x1b[31m"
00053 #define VT100_COLOR_WARN  "\x1b[33m"
00054 #define VT100_COLOR_INFO  "\x1b[39m"
00055 #define VT100_COLOR_DEBUG "\x1b[90m"
00056 
00057 /** default max trace line size in bytes */
00058 #ifdef MBED_TRACE_LINE_LENGTH
00059 #define DEFAULT_TRACE_LINE_LENGTH         MBED_TRACE_LINE_LENGTH
00060 #elif defined YOTTA_CFG_MBED_TRACE_LINE_LENGTH
00061 #warning YOTTA_CFG_MBED_TRACE_LINE_LENGTH is deprecated and will be removed in the future! Use MBED_TRACE_LINE_LENGTH instead.
00062 #define DEFAULT_TRACE_LINE_LENGTH         YOTTA_CFG_MBED_TRACE_LINE_LENGTH
00063 #else
00064 #define DEFAULT_TRACE_LINE_LENGTH         1024
00065 #endif
00066 
00067 /** default max temporary buffer size in bytes, used in
00068     trace_ipv6, trace_ipv6_prefix and trace_array */
00069 #ifdef MBED_TRACE_TMP_LINE_LENGTH
00070 #define DEFAULT_TRACE_TMP_LINE_LEN        MBED_TRACE_TMP_LINE_LENGTH
00071 #elif defined YOTTA_CFG_MBED_TRACE_TMP_LINE_LEN
00072 #warning The YOTTA_CFG_MBED_TRACE_TMP_LINE_LEN flag is deprecated and will be removed in the future! Use MBED_TRACE_TMP_LINE_LENGTH instead.
00073 #define DEFAULT_TRACE_TMP_LINE_LEN        YOTTA_CFG_MBED_TRACE_TMP_LINE_LEN
00074 #elif defined YOTTA_CFG_MTRACE_TMP_LINE_LEN
00075 #warning The YOTTA_CFG_MTRACE_TMP_LINE_LEN flag is deprecated and will be removed in the future! Use MBED_TRACE_TMP_LINE_LENGTH instead.
00076 #define DEFAULT_TRACE_TMP_LINE_LEN        YOTTA_CFG_MTRACE_TMP_LINE_LEN
00077 #else
00078 #define DEFAULT_TRACE_TMP_LINE_LEN        128
00079 #endif
00080 
00081 /** default max filters (include/exclude) length in bytes */
00082 #ifdef MBED_TRACE_FILTER_LENGTH
00083 #define DEFAULT_TRACE_FILTER_LENGTH       MBED_TRACE_FILTER_LENGTH
00084 #else
00085 #define DEFAULT_TRACE_FILTER_LENGTH       24
00086 #endif
00087 
00088 /** default trace configuration bitmask */
00089 #ifdef MBED_TRACE_CONFIG
00090 #define DEFAULT_TRACE_CONFIG              MBED_TRACE_CONFIG
00091 #else
00092 #define DEFAULT_TRACE_CONFIG              TRACE_MODE_COLOR | TRACE_ACTIVE_LEVEL_ALL | TRACE_CARRIAGE_RETURN
00093 #endif
00094 
00095 /** default print function, just redirect str to printf */
00096 static void mbed_trace_realloc( char **buffer, int *length_ptr, int new_length);
00097 static void mbed_trace_default_print(const char *str);
00098 static void mbed_trace_reset_tmp(void);
00099 
00100 typedef struct trace_s {
00101     /** trace configuration bits */
00102     uint8_t trace_config;
00103     /** exclude filters list, related group name */
00104     char *filters_exclude;
00105     /** include filters list, related group name */
00106     char *filters_include;
00107     /** Filters length */
00108     int filters_length;
00109     /** trace line */
00110     char *line;
00111     /** trace line length */
00112     int line_length;
00113     /** temporary data */
00114     char *tmp_data;
00115     /** temporary data array length */
00116     int tmp_data_length;
00117     /** temporary data pointer */
00118     char *tmp_data_ptr;
00119 
00120     /** prefix function, which can be used to put time to the trace line */
00121     char *(*prefix_f)(size_t);
00122     /** suffix function, which can be used to some string to the end of trace line */
00123     char *(*suffix_f)(void);
00124     /** print out function. Can be redirect to flash for example. */
00125     void (*printf)(const char *);
00126     /** print out function for TRACE_LEVEL_CMD */
00127     void (*cmd_printf)(const char *);
00128     /** mutex wait function which can be called to lock against a mutex. */
00129     void (*mutex_wait_f)(void);
00130     /** mutex release function which must be used to release the mutex locked by mutex_wait_f. */
00131     void (*mutex_release_f)(void);
00132     /** number of times the mutex has been locked */
00133     int mutex_lock_count;
00134 } trace_t;
00135 
00136 static trace_t m_trace = {
00137     .trace_config = DEFAULT_TRACE_CONFIG,
00138     .filters_exclude = 0,
00139     .filters_include = 0,
00140     .filters_length = DEFAULT_TRACE_FILTER_LENGTH,
00141     .line = 0,
00142     .line_length = DEFAULT_TRACE_LINE_LENGTH,
00143     .tmp_data = 0,
00144     .tmp_data_length = DEFAULT_TRACE_TMP_LINE_LEN,
00145     .prefix_f = 0,
00146     .suffix_f = 0,
00147     .printf  = mbed_trace_default_print,
00148     .cmd_printf = 0,
00149     .mutex_wait_f = 0,
00150     .mutex_release_f = 0,
00151     .mutex_lock_count = 0
00152 };
00153 
00154 int mbed_trace_init(void)
00155 {
00156     if (m_trace.line == NULL) {
00157         m_trace.line = MBED_TRACE_MEM_ALLOC(m_trace.line_length);
00158     }
00159 
00160     if (m_trace.tmp_data == NULL) {
00161         m_trace.tmp_data = MBED_TRACE_MEM_ALLOC(m_trace.tmp_data_length);
00162     }
00163     m_trace.tmp_data_ptr = m_trace.tmp_data;
00164 
00165     if (m_trace.filters_exclude == NULL) {
00166         m_trace.filters_exclude = MBED_TRACE_MEM_ALLOC(m_trace.filters_length);
00167     }
00168     if (m_trace.filters_include == NULL) {
00169         m_trace.filters_include = MBED_TRACE_MEM_ALLOC(m_trace.filters_length);
00170     }
00171 
00172     if (m_trace.line == NULL ||
00173             m_trace.tmp_data == NULL ||
00174             m_trace.filters_exclude == NULL  ||
00175             m_trace.filters_include == NULL) {
00176         //memory allocation fail
00177         mbed_trace_free();
00178         return -1;
00179     }
00180     memset(m_trace.tmp_data, 0, m_trace.tmp_data_length);
00181     memset(m_trace.filters_exclude, 0, m_trace.filters_length);
00182     memset(m_trace.filters_include, 0, m_trace.filters_length);
00183     memset(m_trace.line, 0, m_trace.line_length);
00184 
00185     return 0;
00186 }
00187 void mbed_trace_free(void)
00188 {
00189     // release memory
00190     MBED_TRACE_MEM_FREE(m_trace.line);
00191     MBED_TRACE_MEM_FREE(m_trace.tmp_data);
00192     MBED_TRACE_MEM_FREE(m_trace.filters_exclude);
00193     MBED_TRACE_MEM_FREE(m_trace.filters_include);
00194 
00195     // reset to default values
00196     m_trace.trace_config = DEFAULT_TRACE_CONFIG;
00197     m_trace.filters_exclude = 0;
00198     m_trace.filters_include = 0;
00199     m_trace.filters_length = DEFAULT_TRACE_FILTER_LENGTH;
00200     m_trace.line = 0;
00201     m_trace.line_length = DEFAULT_TRACE_LINE_LENGTH;
00202     m_trace.tmp_data = 0;
00203     m_trace.tmp_data_length = DEFAULT_TRACE_TMP_LINE_LEN;
00204     m_trace.prefix_f = 0;
00205     m_trace.suffix_f = 0;
00206     m_trace.printf  = mbed_trace_default_print;
00207     m_trace.cmd_printf = 0;
00208     m_trace.mutex_wait_f = 0;
00209     m_trace.mutex_release_f = 0;
00210     m_trace.mutex_lock_count = 0;
00211 }
00212 static void mbed_trace_realloc( char **buffer, int *length_ptr, int new_length)
00213 {
00214     MBED_TRACE_MEM_FREE(*buffer);
00215     *buffer  = MBED_TRACE_MEM_ALLOC(new_length);
00216     *length_ptr = new_length;
00217 }
00218 void mbed_trace_buffer_sizes(int lineLength, int tmpLength)
00219 {
00220     if( lineLength > 0 ) {
00221         mbed_trace_realloc( &(m_trace.line), &m_trace.line_length, lineLength );
00222     }
00223     if( tmpLength > 0 ) {
00224         mbed_trace_realloc( &(m_trace.tmp_data), &m_trace.tmp_data_length, tmpLength);
00225         mbed_trace_reset_tmp();
00226     }
00227 }
00228 void mbed_trace_config_set(uint8_t config)
00229 {
00230     m_trace.trace_config = config;
00231 }
00232 uint8_t mbed_trace_config_get(void)
00233 {
00234     return m_trace.trace_config;
00235 }
00236 void mbed_trace_prefix_function_set(char *(*pref_f)(size_t))
00237 {
00238     m_trace.prefix_f = pref_f;
00239 }
00240 void mbed_trace_suffix_function_set(char *(*suffix_f)(void))
00241 {
00242     m_trace.suffix_f = suffix_f;
00243 }
00244 void mbed_trace_print_function_set(void (*printf)(const char *))
00245 {
00246     m_trace.printf = printf;
00247 }
00248 void mbed_trace_cmdprint_function_set(void (*printf)(const char *))
00249 {
00250     m_trace.cmd_printf = printf;
00251 }
00252 void mbed_trace_mutex_wait_function_set(void (*mutex_wait_f)(void))
00253 {
00254     m_trace.mutex_wait_f = mutex_wait_f;
00255 }
00256 void mbed_trace_mutex_release_function_set(void (*mutex_release_f)(void))
00257 {
00258     m_trace.mutex_release_f = mutex_release_f;
00259 }
00260 void mbed_trace_exclude_filters_set(char *filters)
00261 {
00262     if (filters) {
00263         (void)strncpy(m_trace.filters_exclude, filters, m_trace.filters_length);
00264     } else {
00265         m_trace.filters_exclude[0] = 0;
00266     }
00267 }
00268 const char *mbed_trace_exclude_filters_get(void)
00269 {
00270     return m_trace.filters_exclude;
00271 }
00272 const char *mbed_trace_include_filters_get(void)
00273 {
00274     return m_trace.filters_include;
00275 }
00276 void mbed_trace_include_filters_set(char *filters)
00277 {
00278     if (filters) {
00279         (void)strncpy(m_trace.filters_include, filters, m_trace.filters_length);
00280     } else {
00281         m_trace.filters_include[0] = 0;
00282     }
00283 }
00284 static int8_t mbed_trace_skip(int8_t dlevel, const char *grp)
00285 {
00286     if (dlevel >= 0 && grp != 0) {
00287         // filter debug prints only when dlevel is >0 and grp is given
00288 
00289         /// @TODO this could be much better..
00290         if (m_trace.filters_exclude[0] != '\0' &&
00291                 strstr(m_trace.filters_exclude, grp) != 0) {
00292             //grp was in exclude list
00293             return 1;
00294         }
00295         if (m_trace.filters_include[0] != '\0' &&
00296                 strstr(m_trace.filters_include, grp) == 0) {
00297             //grp was in include list
00298             return 1;
00299         }
00300     }
00301     return 0;
00302 }
00303 static void mbed_trace_default_print(const char *str)
00304 {
00305     puts(str);
00306 }
00307 void mbed_tracef(uint8_t dlevel, const char *grp, const char *fmt, ...)
00308 {
00309     va_list ap;
00310     va_start(ap, fmt);
00311     mbed_vtracef(dlevel, grp, fmt, ap);
00312     va_end(ap);
00313 }
00314 void mbed_vtracef(uint8_t dlevel, const char* grp, const char *fmt, va_list ap)
00315 {
00316     if ( m_trace.mutex_wait_f ) {
00317         m_trace.mutex_wait_f();
00318         m_trace.mutex_lock_count++;
00319     }
00320 
00321     if (NULL == m_trace.line) {
00322         goto end;
00323     }
00324 
00325     m_trace.line[0] = 0; //by default trace is empty
00326 
00327     if (mbed_trace_skip(dlevel, grp) || fmt == 0 || grp == 0 || !m_trace.printf) {
00328         //return tmp data pointer back to the beginning
00329         mbed_trace_reset_tmp();
00330         goto end;
00331     }
00332     if ((m_trace.trace_config & TRACE_MASK_LEVEL) &  dlevel) {
00333         bool color = (m_trace.trace_config & TRACE_MODE_COLOR) != 0;
00334         bool plain = (m_trace.trace_config & TRACE_MODE_PLAIN) != 0;
00335         bool cr    = (m_trace.trace_config & TRACE_CARRIAGE_RETURN) != 0;
00336 
00337         int retval = 0, bLeft = m_trace.line_length;
00338         char *ptr = m_trace.line;
00339         if (plain == true || dlevel == TRACE_LEVEL_CMD) {
00340             //add trace data
00341             retval = vsnprintf(ptr, bLeft, fmt, ap);
00342             if (dlevel == TRACE_LEVEL_CMD && m_trace.cmd_printf) {
00343                 m_trace.cmd_printf(m_trace.line);
00344                 m_trace.cmd_printf("\n");
00345             } else {
00346                 //print out whole data
00347                 m_trace.printf(m_trace.line);
00348             }
00349         } else {
00350             if (color) {
00351                 if (cr) {
00352                     retval = snprintf(ptr, bLeft, "\r\x1b[2K");
00353                     if (retval >= bLeft) {
00354                         retval = 0;
00355                     }
00356                     if (retval > 0) {
00357                         ptr += retval;
00358                         bLeft -= retval;
00359                     }
00360                 }
00361                 if (bLeft > 0) {
00362                     //include color in ANSI/VT100 escape code
00363                     switch (dlevel) {
00364                         case (TRACE_LEVEL_ERROR):
00365                             retval = snprintf(ptr, bLeft, "%s", VT100_COLOR_ERROR);
00366                             break;
00367                         case (TRACE_LEVEL_WARN):
00368                             retval = snprintf(ptr, bLeft, "%s", VT100_COLOR_WARN);
00369                             break;
00370                         case (TRACE_LEVEL_INFO):
00371                             retval = snprintf(ptr, bLeft, "%s", VT100_COLOR_INFO);
00372                             break;
00373                         case (TRACE_LEVEL_DEBUG):
00374                             retval = snprintf(ptr, bLeft, "%s", VT100_COLOR_DEBUG);
00375                             break;
00376                         default:
00377                             color = 0; //avoid unneeded color-terminate code
00378                             retval = 0;
00379                             break;
00380                     }
00381                     if (retval >= bLeft) {
00382                         retval = 0;
00383                     }
00384                     if (retval > 0 && color) {
00385                         ptr += retval;
00386                         bLeft -= retval;
00387                     }
00388                 }
00389 
00390             }
00391             if (bLeft > 0 && m_trace.prefix_f) {
00392                 //find out length of body
00393                 size_t sz = 0;
00394                 va_list ap2;
00395                 va_copy(ap2, ap);
00396                 sz = vsnprintf(NULL, 0, fmt, ap2) + retval + (retval ? 4 : 0);
00397                 va_end(ap2);
00398                 //add prefix string
00399                 retval = snprintf(ptr, bLeft, "%s", m_trace.prefix_f(sz));
00400                 if (retval >= bLeft) {
00401                     retval = 0;
00402                 }
00403                 if (retval > 0) {
00404                     ptr += retval;
00405                     bLeft -= retval;
00406                 }
00407             }
00408             if (bLeft > 0) {
00409                 //add group tag
00410                 switch (dlevel) {
00411                     case (TRACE_LEVEL_ERROR):
00412                         retval = snprintf(ptr, bLeft, "[ERR ][%-4s]: ", grp);
00413                         break;
00414                     case (TRACE_LEVEL_WARN):
00415                         retval = snprintf(ptr, bLeft, "[WARN][%-4s]: ", grp);
00416                         break;
00417                     case (TRACE_LEVEL_INFO):
00418                         retval = snprintf(ptr, bLeft, "[INFO][%-4s]: ", grp);
00419                         break;
00420                     case (TRACE_LEVEL_DEBUG):
00421                         retval = snprintf(ptr, bLeft, "[DBG ][%-4s]: ", grp);
00422                         break;
00423                     default:
00424                         retval = snprintf(ptr, bLeft, "              ");
00425                         break;
00426                 }
00427                 if (retval >= bLeft) {
00428                     retval = 0;
00429                 }
00430                 if (retval > 0) {
00431                     ptr += retval;
00432                     bLeft -= retval;
00433                 }
00434             }
00435             if (retval > 0 && bLeft > 0) {
00436                 //add trace text
00437                 retval = vsnprintf(ptr, bLeft, fmt, ap);
00438                 if (retval >= bLeft) {
00439                     retval = 0;
00440                 }
00441                 if (retval > 0) {
00442                     ptr += retval;
00443                     bLeft -= retval;
00444                 }
00445             }
00446 
00447             if (retval > 0 && bLeft > 0  && m_trace.suffix_f) {
00448                 //add suffix string
00449                 retval = snprintf(ptr, bLeft, "%s", m_trace.suffix_f());
00450                 if (retval >= bLeft) {
00451                     retval = 0;
00452                 }
00453                 if (retval > 0) {
00454                     ptr += retval;
00455                     bLeft -= retval;
00456                 }
00457             }
00458 
00459             if (retval > 0 && bLeft > 0  && color) {
00460                 //add zero color VT100 when color mode
00461                 retval = snprintf(ptr, bLeft, "\x1b[0m");
00462                 if (retval >= bLeft) {
00463                     retval = 0;
00464                 }
00465                 if (retval > 0) {
00466                     // not used anymore
00467                     //ptr += retval;
00468                     //bLeft -= retval;
00469                 }
00470             }
00471             //print out whole data
00472             m_trace.printf(m_trace.line);
00473         }
00474         //return tmp data pointer back to the beginning
00475         mbed_trace_reset_tmp();
00476     }
00477 
00478 end:
00479     if ( m_trace.mutex_release_f ) {
00480         // Store the mutex lock count to temp variable so that it won't get
00481         // clobbered during last loop iteration when mutex gets released
00482         int count = m_trace.mutex_lock_count;
00483         m_trace.mutex_lock_count = 0;
00484         // Since the helper functions (eg. mbed_trace_array) are used like this:
00485         //   mbed_tracef(TRACE_LEVEL_INFO, "grp", "%s", mbed_trace_array(some_array))
00486         // The helper function MUST acquire the mutex if it modifies any buffers. However
00487         // it CANNOT unlock the mutex because that would allow another thread to acquire
00488         // the mutex after helper function unlocks it and before mbed_tracef acquires it
00489         // for itself. This means that here we have to unlock the mutex as many times
00490         // as it was acquired by trace function and any possible helper functions.
00491         do {
00492             m_trace.mutex_release_f();
00493         } while (--count > 0);
00494     }
00495 }
00496 static void mbed_trace_reset_tmp(void)
00497 {
00498     m_trace.tmp_data_ptr = m_trace.tmp_data;
00499 }
00500 const char *mbed_trace_last(void)
00501 {
00502     return m_trace.line;
00503 }
00504 /* Helping functions */
00505 #define tmp_data_left()  m_trace.tmp_data_length-(m_trace.tmp_data_ptr-m_trace.tmp_data)
00506 #if MBED_CONF_MBED_TRACE_FEA_IPV6 == 1
00507 char *mbed_trace_ipv6(const void *addr_ptr)
00508 {
00509     /** Acquire mutex. It is released before returning from mbed_vtracef. */
00510     if ( m_trace.mutex_wait_f ) {
00511         m_trace.mutex_wait_f();
00512         m_trace.mutex_lock_count++;
00513     }
00514     char *str = m_trace.tmp_data_ptr;
00515     if (str == NULL) {
00516         return "";
00517     }
00518     if (tmp_data_left() < 41) {
00519         return "";
00520     }
00521     if (addr_ptr == NULL) {
00522         return "<null>";
00523     }
00524     str[0] = 0;
00525     m_trace.tmp_data_ptr += ip6tos(addr_ptr, str) + 1;
00526     return str;
00527 }
00528 char *mbed_trace_ipv6_prefix(const uint8_t *prefix, uint8_t prefix_len)
00529 {
00530     /** Acquire mutex. It is released before returning from mbed_vtracef. */
00531     if ( m_trace.mutex_wait_f ) {
00532         m_trace.mutex_wait_f();
00533         m_trace.mutex_lock_count++;
00534     }
00535     char *str = m_trace.tmp_data_ptr;
00536     if (str == NULL) {
00537         return "";
00538     }
00539     if (tmp_data_left() < 45) {
00540         return "";
00541     }
00542 
00543     if ((prefix_len != 0 && prefix == NULL) || prefix_len > 128) {
00544         return "<err>";
00545     }
00546 
00547     m_trace.tmp_data_ptr += ip6_prefix_tos(prefix, prefix_len, str) + 1;
00548     return str;
00549 }
00550 #endif //MBED_CONF_MBED_TRACE_FEA_IPV6
00551 char *mbed_trace_array(const uint8_t *buf, uint16_t len)
00552 {
00553     /** Acquire mutex. It is released before returning from mbed_vtracef. */
00554     if ( m_trace.mutex_wait_f ) {
00555         m_trace.mutex_wait_f();
00556         m_trace.mutex_lock_count++;
00557     }
00558     int i, bLeft = tmp_data_left();
00559     char *str, *wptr;
00560     str = m_trace.tmp_data_ptr;
00561     if (len == 0 || str == NULL || bLeft == 0) {
00562         return "";
00563     }
00564     if (buf == NULL) {
00565         return "<null>";
00566     }
00567     wptr = str;
00568     wptr[0] = 0;
00569     const uint8_t *ptr = buf;
00570     char overflow = 0;
00571     for (i = 0; i < len; i++) {
00572         if (bLeft <= 3) {
00573             overflow = 1;
00574             break;
00575         }
00576         int retval = snprintf(wptr, bLeft, "%02x:", *ptr++);
00577         if (retval <= 0 || retval > bLeft) {
00578             break;
00579         }
00580         bLeft -= retval;
00581         wptr += retval;
00582     }
00583     if (wptr > str) {
00584         if( overflow ) {
00585             // replace last character as 'star',
00586             // which indicate buffer len is not enough
00587             *(wptr - 1) = '*';
00588         } else {
00589             //null to replace last ':' character
00590             *(wptr - 1) = 0;
00591         }
00592     }
00593     m_trace.tmp_data_ptr = wptr;
00594     return str;
00595 }