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mdns: Use memcpy() for copy to support non-text TXTs

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* Original commit: espressif/esp-idf@6aefe9c185
This commit is contained in:
David Cermak
2022-01-21 15:27:45 +01:00
committed by suren-gabrielyan-espressif
parent fcb5515f1e
commit 6cdf5ee074
1 changed files with 36 additions and 18 deletions
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54
components/mdns/mdns.c
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@ -513,6 +513,37 @@ static inline uint8_t _mdns_append_string(uint8_t * packet, uint16_t * index, co
return len + 1;
}
/**
* @brief appends one TXT record ("key=value" or "key")
*
* @param packet MDNS packet
* @param index offset in the packet
* @param txt one txt record
*
* @return length of added data: length of the added txt value + 1 on success
* 0 if data won't fit the packet
* -1 if invalid TXT entry
*/
static inline int append_one_txt_record_entry(uint8_t * packet, uint16_t * index, mdns_txt_linked_item_t * txt)
{
if (txt == NULL || txt->key == NULL) {
return -1;
}
size_t key_len = strlen(txt->key);
size_t len = key_len + txt->value_len + (txt->value ? 1 : 0);
if ((*index + len + 1) >= MDNS_MAX_PACKET_SIZE) {
return 0;
}
_mdns_append_u8(packet, index, len);
memcpy(packet + *index, txt->key, key_len);
if (txt->value) {
packet[*index + key_len] = '=';
memcpy(packet + *index + key_len + 1, txt->value, txt->value_len);
}
*index += len;
return len + 1;
}
/**
* @brief appends FQDN to a packet, incrementing the index and
* compressing the output if previous occurrence of the string (or part of it) has been found
@ -775,19 +806,13 @@ static uint16_t _mdns_append_txt_record(uint8_t * packet, uint16_t * index, mdns
uint16_t data_len_location = *index - 2;
uint16_t data_len = 0;
char * tmp;
mdns_txt_linked_item_t * txt = service->txt;
while (txt) {
if (asprintf(&tmp, "%s%s%.*s", txt->key, txt->value ? "=" : "", txt->value_len, txt->value) > 0) {
uint8_t l = _mdns_append_string(packet, index, tmp);
free(tmp);
if (!l) {
return 0;
}
int l = append_one_txt_record_entry(packet, index, txt);
if (l > 0) {
data_len += l;
} else {
HOOK_MALLOC_FAILED;
// continue
} else if (l == 0) { // TXT entry won't fit into the mdns packet
return 0;
}
txt = txt->next;
}
@ -2574,17 +2599,10 @@ static int _mdns_check_txt_collision(mdns_service_t * service, const uint8_t * d
uint8_t ours[len];
uint16_t index = 0;
char * tmp;
txt = service->txt;
while (txt) {
if (asprintf(&tmp, "%s%s%.*s", txt->key, txt->value ? "=" : "", txt->value_len, txt->value) > 0) {
_mdns_append_string(ours, &index, tmp);
free(tmp);
} else {
HOOK_MALLOC_FAILED;
// continue
}
append_one_txt_record_entry(ours, &index, txt);
txt = txt->next;
}