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#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <osmocom/gsm/apn.h>
#define APN_OI_GPRS_FMT "mnc%03u.mcc%03u.gprs"
#define APN_GPRS_FMT "%s.mnc%03u.mcc%03u.gprs"
static char apn_strbuf[APN_MAXLEN+1];
char *osmo_apn_qualify(unsigned int mcc, unsigned int mnc, const char *ni)
{
snprintf(apn_strbuf, sizeof(apn_strbuf)-1, APN_GPRS_FMT,
ni, mnc, mcc);
apn_strbuf[sizeof(apn_strbuf)-1] = '\0';
return apn_strbuf;
}
char *osmo_apn_qualify_from_imsi(const char *imsi,
const char *ni, int have_3dig_mnc)
{
char cbuf[3+1], nbuf[3+1];
strncpy(cbuf, imsi, 3);
cbuf[3] = '\0';
if (have_3dig_mnc) {
strncpy(nbuf, imsi+3, 3);
nbuf[3] = '\0';
} else {
strncpy(nbuf, imsi+3, 2);
nbuf[2] = '\0';
}
return osmo_apn_qualify(atoi(cbuf), atoi(nbuf), ni);
}
/**
* Convert an encoded APN into a dot-separated string.
*
* \param out_str the destination buffer (size must be >= max(app_enc_len,1))
* \param apn_enc the encoded APN
* \param apn_enc_len the length of the encoded APN
*
* \returns out_str on success and NULL otherwise
*/
char * osmo_apn_to_str(char *out_str, const uint8_t *apn_enc, size_t apn_enc_len)
{
char *str = out_str;
size_t rest_chars = apn_enc_len;
while (rest_chars > 0 && apn_enc[0]) {
size_t label_size = apn_enc[0];
if (label_size + 1 > rest_chars)
return NULL;
memmove(str, apn_enc + 1, label_size);
str += label_size;
rest_chars -= label_size + 1;
apn_enc += label_size + 1;
if (rest_chars)
*(str++) = '.';
}
str[0] = '\0';
return out_str;
}
/**
* Convert a dot-separated string into an encoded APN.
*
* \param apn_enc the encoded APN
* \param max_apn_enc_len the size of the apn_enc buffer
* \param str the source string
*
* \returns out_str on success and NULL otherwise
*/
int osmo_apn_from_str(uint8_t *apn_enc, size_t max_apn_enc_len, const char *str)
{
uint8_t *last_len_field;
int len;
/* Can we even write the length field to the output? */
if (max_apn_enc_len == 0)
return -1;
/* Remember where we need to put the length once we know it */
last_len_field = apn_enc;
len = 1;
apn_enc += 1;
while (str[0]) {
if (len >= max_apn_enc_len)
return -1;
if (str[0] == '.') {
*last_len_field = (apn_enc - last_len_field) - 1;
last_len_field = apn_enc;
} else {
*apn_enc = str[0];
}
apn_enc += 1;
str += 1;
len += 1;
}
*last_len_field = (apn_enc - last_len_field) - 1;
return len;
}
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