Skip to content

Commit

Permalink
Merge pull request #97 from CESNET/ssdp_fix_payload_handling
Browse files Browse the repository at this point in the history 
SSDP Plugin: Fixed payload handling.
  • Loading branch information
@SiskaPavel
SiskaPavel authored Jul 26, 2022
2 parents 6d9b63e + 17d3a18 commit 175d94d
Show file tree
Hide file tree
Showing 2 changed files with 41 additions and 31 deletions.
64 changes: 37 additions & 27 deletions process/ssdp.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,21 +142,26 @@ void SSDPPlugin::finish(bool print_stats)
* \param [in] ip_version IP version of the Location url being parsed.
* \return Parsed port number on success, 0 otherwise.
*/
uint16_t SSDPPlugin::parse_loc_port(char *data, uint8_t ip_version)
uint16_t SSDPPlugin::parse_loc_port(const char *data, unsigned data_len, uint8_t ip_version)
{
uint16_t port;
char *end_ptr = nullptr;
const void *data_mem = static_cast<const void *>(data);

if (ip_version == IP::v6) {
data = strchr(data, ']');
data_mem = memchr(data_mem, ']', data_len);
} else {
data = strchr(data, '.');
data_mem = memchr(data_mem, '.', data_len);
}
data = strchr(data, ':');
if (data_mem == nullptr) {
return 0;
}
data_mem = memchr(data_mem, ':', data_len);

if (data == nullptr) {
if (data_mem == nullptr) {
return 0;
}
data = static_cast<const char *>(data_mem);
data++;

port = strtol(data, &end_ptr, 0);
Expand All @@ -174,7 +179,7 @@ uint16_t SSDPPlugin::parse_loc_port(char *data, uint8_t ip_version)
* \param [in] len Lenght of the desired header.
* \return True if the header is found, otherwise false.
*/
bool SSDPPlugin::get_header_val(char **data, const char *header, const int len)
bool SSDPPlugin::get_header_val(const char **data, const char *header, const int len)
{
if (strncasecmp(*data, header, len) == 0 && (*data)[len] == ':') {
(*data) += len + 1;
Expand All @@ -193,34 +198,33 @@ bool SSDPPlugin::get_header_val(char **data, const char *header, const int len)
* \param [in] payload_len Lenght of payload data
* \param [in] conf Struct containing parser configuration.
*/
void SSDPPlugin::parse_headers(char *data, size_t payload_len, header_parser_conf conf)
void SSDPPlugin::parse_headers(const uint8_t *data, size_t payload_len, header_parser_conf conf)
{
char *ptr = data;
char *old_ptr = ptr;
const char *ptr = (const char *)(data);
const char *old_ptr = ptr;
size_t len = 0;

while (*ptr != '\0' && len <= payload_len) {
if (*ptr == '\n' && *(ptr - 1) == '\r') {
*(ptr - 1) = '\0';
for (unsigned j = 0, i = 0; j < conf.select_cnt; j++) {
i = conf.select[j];
if (get_header_val(&old_ptr, conf.headers[i], strlen(conf.headers[i]))) {
switch ((header_types) i) {
case ST:
if (get_header_val(&old_ptr, "urn", strlen("urn"))) {
SSDP_DEBUG_MSG("%s\n", old_ptr);
append_value(conf.ext->st, SSDP_URN_LEN, old_ptr);
append_value(conf.ext->st, SSDP_URN_LEN, old_ptr, ptr-old_ptr);
}
break;
case NT:
if (get_header_val(&old_ptr, "urn", strlen("urn"))) {
SSDP_DEBUG_MSG("%s\n", old_ptr);
append_value(conf.ext->nt, SSDP_URN_LEN, old_ptr);
append_value(conf.ext->nt, SSDP_URN_LEN, old_ptr, ptr-old_ptr);
}
break;
case LOCATION:
{
uint16_t port = parse_loc_port(old_ptr, conf.ip_version);
uint16_t port = parse_loc_port(old_ptr, ptr-old_ptr,conf.ip_version);

if (port > 0) {
SSDP_DEBUG_MSG("%d <- %d\n", conf.ext->port, port);
Expand All @@ -230,11 +234,11 @@ void SSDPPlugin::parse_headers(char *data, size_t payload_len, header_parser_con
}
case USER_AGENT:
SSDP_DEBUG_MSG("%s\n", old_ptr);
append_value(conf.ext->user_agent, SSDP_USER_AGENT_LEN, old_ptr);
append_value(conf.ext->user_agent, SSDP_USER_AGENT_LEN, old_ptr, ptr-old_ptr);
break;
case SERVER:
SSDP_DEBUG_MSG("%s\n", old_ptr);
append_value(conf.ext->server, SSDP_SERVER_LEN, old_ptr);
append_value(conf.ext->server, SSDP_SERVER_LEN, old_ptr, ptr-old_ptr);
break;
default:
break;
Expand All @@ -259,14 +263,22 @@ void SSDPPlugin::parse_headers(char *data, size_t payload_len, header_parser_con
* \param [in] entry_max Maximum length if the entry.
* \param [in] value String containing the new entry.
*/
void SSDPPlugin::append_value(char *curr_entry, unsigned entry_max, char *value)
void SSDPPlugin::append_value(char *curr_entry, unsigned entry_max, const char *value, unsigned value_len)
{
if (strlen(curr_entry) + strlen(value) + 1 < entry_max) {
if (strstr(curr_entry, value) == nullptr) {
SSDP_DEBUG_MSG("New entry\n");
strcat(curr_entry, value);
strcat(curr_entry, ";");
if (strlen(curr_entry) + value_len + 1 < entry_max) {
// return if value already in curr_entry
for (unsigned i = 0; i < strlen(curr_entry) - value_len; i++) {
if (strlen(curr_entry) < value_len) {
break;
}
if (strncmp(&curr_entry[i], value, value_len) == 0) {
return;
}
}

SSDP_DEBUG_MSG("New entry\n");
strncat(curr_entry, value, value_len);
strcat(curr_entry, ";");
}
}

Expand All @@ -285,24 +297,22 @@ void SSDPPlugin::parse_ssdp_message(Flow &rec, const Packet &pkt)
rec.ip_version,
static_cast<RecordExtSSDP *>(rec.get_extension(RecordExtSSDP::REGISTERED_ID))
};
char *data = (char *) pkt.payload;
size_t payload_len = pkt.payload_len;

total++;
if (data[0] == 'N') {
if (pkt.payload[0] == 'N') {
notifies++;
SSDP_DEBUG_MSG("Notify #%d\n", notifies);
int notify_headers[] = { NT, LOCATION, SERVER };
parse_conf.select = notify_headers;
parse_conf.select_cnt = sizeof(notify_headers) / sizeof(notify_headers[0]);
parse_headers(data, payload_len, parse_conf);
} else if (data[0] == 'M') {
parse_headers(pkt.payload, pkt.payload_len, parse_conf);
} else if (pkt.payload[0] == 'M') {
searches++;
SSDP_DEBUG_MSG("M-search #%d\n", searches);
int search_headers[] = { ST, USER_AGENT };
parse_conf.select = search_headers;
parse_conf.select_cnt = sizeof(search_headers) / sizeof(search_headers[0]);
parse_headers(data, payload_len, parse_conf);
parse_headers(pkt.payload, pkt.payload_len, parse_conf);
}
SSDP_DEBUG_MSG("\n");
}
Expand Down
8 changes: 4 additions & 4 deletions process/ssdp.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -217,11 +217,11 @@ class SSDPPlugin : public ProcessPlugin
uint32_t searches; /**< Total number of parsed SSDP m-searches. */
uint32_t total; /**< Total number of parsed SSDP packets. */

uint16_t parse_loc_port(char *data, uint8_t ip_version);
bool get_header_val(char **data, const char *header, const int len);
void parse_headers(char *data, size_t payload_len, header_parser_conf conf);
uint16_t parse_loc_port(const char *data, unsigned data_len, uint8_t ip_version);
bool get_header_val(const char **data, const char *header, const int len);
void parse_headers(const uint8_t *data, size_t payload_len, header_parser_conf conf);
void parse_ssdp_message(Flow &rec, const Packet &pkt);
void append_value(char *curr_entry, unsigned entry_max, char *value);
void append_value(char *curr_entry, unsigned entry_max, const char *value, unsigned value_len);
};

}
Expand Down

0 comments on commit 175d94d

Please sign in to comment.