CellularUtil.cpp

00001 /*
00002  * Copyright (c) , Arm Limited and affiliates.
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License");
00006  * you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  *     http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS,
00013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 #include "CellularUtil.h"
00018 #include <string.h>
00019 #include <stdlib.h>
00020 
00021 namespace mbed_cellular_util {
00022 
00023 void convert_ipv6(char* ip)
00024 {
00025     if (!ip) {
00026         return;
00027     }
00028 
00029     int len = strlen(ip);
00030     int pos = 0;
00031     int i;
00032 
00033     for (i = 0; i < len; i++) {
00034         if (ip[i] == '.') {
00035             pos++;
00036         }
00037         if (pos > 3) {
00038             break;
00039         }
00040     }
00041 
00042     // more that 3 periods mean that it was ipv6 but in format of a1.a2.a3.a4.a5.a6.a7.a8.a9.a10.a11.a12.a13.a14.a15.a16
00043     // we need to convert it to hexadecimal format separated with colons
00044     if (pos > 3) {
00045         pos = 0;
00046         int ip_pos = 0;
00047         char b;
00048         bool set_colon = false;
00049         for (i = 0; i < len; i++) {
00050             if (ip[i] == '.') {
00051                 b = (char)strtol (ip+ip_pos, NULL, 10); // convert to char to int so we can change it to hex string
00052                 pos += char_str_to_hex_str(&b, 1, ip+pos, !set_colon); // omit leading zeroes with using set_colon flag
00053                 if (set_colon) {
00054                     ip[pos++] = ':';
00055                     set_colon = false;
00056                 } else {
00057                     set_colon = true;
00058                 }
00059                 ip_pos = i+1; // skip the '.'
00060             }
00061 
00062             // handle the last part which does not end with '.' but '\0'
00063             if (i == len -1) {
00064                 b = (char)strtol(ip+ip_pos, NULL, 10);
00065                 pos += char_str_to_hex_str(&b, 1, ip+pos, !set_colon);
00066                 ip[pos] = '\0';
00067             }
00068         }
00069     }
00070 }
00071 
00072 // For example "32.1.13.184.0.0.205.48.0.0.0.0.0.0.0.0"
00073 void separate_ip4like_addresses(char* orig, char* ip, size_t ip_size, char* ip2, size_t ip2_size)
00074 {
00075     // ipv4-like notation
00076     int len = strlen(orig);
00077     int count = 0, i = 0, pos = 0;
00078     char *temp;
00079 
00080     for (; i < len; i++) {
00081         if (orig[i] == '.') {
00082             count++;
00083             if (count == 4) {
00084                 pos = i;
00085             } else if (count == 16) {
00086                 pos = i;
00087             }
00088         }
00089     }
00090 
00091     if (count == 3) { // normal ipv4, copy to ip
00092         if (ip_size > strlen(orig)) {
00093             memcpy(ip, orig, strlen(orig));
00094             ip[strlen(orig)] = '\0';
00095         } else {
00096             ip[0] = '\0';
00097         }
00098         if (ip2) {
00099             ip2[0] = '\0';
00100         }
00101     } else if (count == 7) { // ipv4 and subnet mask. Need to separate those.
00102         temp = &orig[pos];
00103         if ((uint8_t)ip_size > temp-orig) {
00104             memcpy(ip, orig, temp-orig);
00105             ip[temp-orig] = '\0';
00106         }
00107         temp++; // skip the '.'
00108         if (ip2 && (ip2_size > strlen(temp))) {
00109             memcpy(ip2, temp, strlen(temp));
00110             ip2[strlen(temp)] = '\0';
00111         }
00112     } else if (count == 15) { // only one ipv6 address in ipv4-like notation
00113         if (ip_size > strlen(orig)) {
00114             memcpy(ip, orig, strlen(orig));
00115             ip[strlen(orig)] = '\0';
00116             convert_ipv6(ip);
00117         } else {
00118             ip[0] = '\0';
00119         }
00120         if (ip2) {
00121             ip2[0] = '\0';
00122         }
00123     } else if (count == 31){ // ipv6 + ipv6subnet mask in ipv4-like notation separated by dot '.'
00124         temp = &orig[pos];
00125         if ((uint8_t)ip_size > temp-orig) {
00126             memcpy(ip, orig, temp-orig);
00127             ip[temp-orig] = '\0';
00128             convert_ipv6(ip);
00129         }
00130         temp++; // skip the '.'
00131         if (ip2 && (ip2_size > strlen(temp))) {
00132             memcpy(ip2, temp, strlen(temp));
00133             ip2[strlen(temp)] = '\0';
00134             convert_ipv6(ip2);
00135         }
00136     }
00137 }
00138 
00139 void separate_ip_addresses(char* orig, char* ip, size_t ip_size, char* ip2, size_t ip2_size)
00140 {
00141     // orig can include ipv4, ipv6, both or two ip4/ipv6 addresses.
00142     // also format depends on possible AT+CGPIAF
00143     if (!orig || !ip) {
00144         if (ip) {
00145             ip[0] = '\0';
00146         }
00147         if (ip2) {
00148             ip2[0] = '\0';
00149         }
00150         return;
00151     }
00152     // 1. try to found ':'. If it's found then we know that possible addresses are separated with space
00153     char *temp;
00154     temp = strchr(orig, ':');
00155 
00156     if (temp != NULL) {
00157         // found ':'
00158         temp = strstr(orig, " ");
00159         // found space as separator and it wasn't in beginning --> contains 2 ip addresses
00160         if (temp && temp != orig) {
00161             if ((uint8_t)ip_size > temp-orig) {
00162                 memcpy(ip, orig, temp-orig);
00163                 ip[temp-orig] = '\0';
00164             } else {
00165                 ip[0] = '\0';
00166             }
00167             temp++; // skip the space
00168             if (ip2 && (ip2_size > strlen(temp))) {
00169                 memcpy(ip2, temp, strlen(temp));
00170                 ip2[strlen(temp)] = '\0';
00171             } else if (ip2) {
00172                 ip2[0] = '\0';
00173             }
00174         } else {
00175             // Space was the first char or no space found ---> only one ip, copy to ip
00176             size_t size = strlen(orig);
00177             if (temp) {
00178                 size = strlen(temp);
00179             }
00180 
00181             if (ip_size > size) {
00182                 memcpy(ip, orig, size);
00183                 ip[size] = '\0';
00184             } else {
00185                 ip[0] = '\0';
00186             }
00187             if (ip2) {
00188                 ip2[0] = '\0';
00189             }
00190         }
00191     } else {
00192         temp = strstr(orig, " ");
00193         // found space as separator and it wasn't in beginning --> contains 2 ip addresses
00194         if (temp && temp != orig) {
00195             separate_ip4like_addresses(temp++, ip2, ip2_size, NULL, 0);
00196             orig[temp-orig-1] = '\0';
00197             separate_ip4like_addresses(orig, ip, ip_size, NULL, 0);
00198             orig[temp-orig-1] = ' '; // put space back to keep orig as original
00199         }
00200         else {
00201             separate_ip4like_addresses(orig, ip, ip_size, ip2, ip2_size);
00202         }
00203     }
00204 }
00205 
00206 void prefer_ipv6(char* ip, size_t ip_size, char* ip2, size_t ip2_size)
00207 {
00208     if (!ip || !ip2) {
00209         return;
00210     }
00211     // assume that that ipv6 is already in formatted to use ':'
00212     // 1. try to found ':'. If it's found then we know that this is ipv6
00213     char *temp;
00214     temp = strchr(ip, ':');
00215     if (temp) {
00216         // ip has ipv6 address, we can leave
00217         return;
00218     } else {
00219         // ip was not ipv6, check if ip2 is
00220         temp = strchr(ip2, ':');
00221         if (temp) {
00222             // ipv6 was found in ip2 but not in ip ---> we must swap them. Sadly ip and ip2 might not be pointers
00223             // so we can't just swap them, must use copy.
00224             if (strlen(ip) < ip2_size && strlen(ip2) < ip_size && strlen(ip) < 64) {
00225                 char tmp[64];
00226                 strncpy(tmp, ip, strlen(ip));
00227                 tmp[strlen(ip)] = '\0';
00228                 strncpy(ip, ip2, strlen(ip2));
00229                 ip[strlen(ip2)] = '\0';
00230                 strncpy(ip2, tmp, strlen(tmp));
00231                 ip2[strlen(tmp)] = '\0';
00232             }
00233         }
00234     }
00235 }
00236 
00237 void int_to_hex_str(uint8_t num, char* buf)
00238 {
00239     char charNum = num;
00240     char_str_to_hex_str(&charNum, 1, buf);
00241 }
00242 
00243 int hex_str_to_int(const char *hex_string, int hex_string_length)
00244 {
00245     const int base = 16;
00246     int character_as_integer, integer_output = 0;
00247 
00248     for (int i=0;i<hex_string_length && hex_string[i] != '\0';i++) {
00249         if (hex_string[i] >= '0' && hex_string[i] <= '9') {
00250             character_as_integer = hex_string[i] - '0';
00251         } else if (hex_string[i] >= 'A' && hex_string[i] <= 'F') {
00252             character_as_integer = hex_string[i] - 'A' + 10;
00253         } else {
00254             character_as_integer = hex_string[i] - 'a' + 10;
00255         }
00256         integer_output *= base;
00257         integer_output += character_as_integer;
00258     }
00259 
00260     return integer_output;
00261 }
00262 
00263 int hex_str_to_char_str(const char* str, uint16_t len, char *buf)
00264 {
00265     int strcount = 0;
00266     for (int i = 0; i+1 < len; i += 2) {
00267         int upper = hex_str_to_int(str+i, 1);
00268         int lower = hex_str_to_int(str+i+1, 1);
00269         buf[strcount] = ((upper<<4) & 0xF0) | (lower & 0x0F);
00270         strcount++;
00271     }
00272 
00273     return strcount;
00274 }
00275 
00276 void uint_to_binary_str(uint32_t num, char* str, int str_size, int bit_cnt)
00277 {
00278     if (!str || str_size < bit_cnt) {
00279         return;
00280     }
00281     int tmp, pos = 0;
00282 
00283     for (int i = 31; i >= 0; i--) {
00284         tmp = num >> i;
00285         if (i < bit_cnt) {
00286             if (tmp&1) {
00287                 str[pos] = 1 + '0';
00288             } else {
00289                 str[pos] = 0 + '0';
00290             }
00291             pos++;
00292         }
00293     }
00294 }
00295 
00296 int char_str_to_hex_str(const char* str, uint16_t len, char *buf, bool omit_leading_zero)
00297 {
00298     if (!str || !buf) {
00299         return 0;
00300     }
00301 
00302     char *ptr = buf;
00303     int i=0;
00304     while (i < len) {
00305         if (omit_leading_zero == true && i == 0 && !(str[i]>>4 & 0x0F)) {
00306             *ptr++ = hex_values[(str[i]) & 0x0F];
00307         } else {
00308             *ptr++ = hex_values[((str[i])>>4) & 0x0F];
00309             *ptr++ = hex_values[(str[i]) & 0x0F];
00310         }
00311         i++;
00312     }
00313     return ptr-buf;
00314 }
00315 
00316 uint16_t get_dynamic_ip_port()
00317 {
00318     static uint16_t port;
00319     port++;
00320     if (port < 49152) {
00321         port = 49152;
00322     }
00323     return port;
00324 }
00325 
00326 } // namespace mbed_cellular_util