diff options
Diffstat (limited to 'rpcap-protocol.c')
| -rw-r--r-- | rpcap-protocol.c | 118 |
1 files changed, 65 insertions, 53 deletions
diff --git a/rpcap-protocol.c b/rpcap-protocol.c index 5aeca462..9b8f6638 100644 --- a/rpcap-protocol.c +++ b/rpcap-protocol.c @@ -50,54 +50,6 @@ */ /* - * This function checks whether the version contained into the message is - * compatible with the one handled by this implementation. - * - * Right now, this function does not have any sophisticated task: if the - * versions are different, it returns -1 and it discards the message. - * If new versions of the protocol are created, there will need to be - * a negotiation phase early in the process of connecting to our peer, - * so that the highest version supported by both sides can be used. - * - * \param sock: the socket that has to be used to receive data. This - * function can read data from socket in case the version contained into - * the message is not compatible with ours. In that case, all the message - * is purged from the socket, so that the following recv() calls will - * return a new (clean) message. - * - * \param header: a pointer to and 'rpcap_header' structure that keeps - * the data received from the network (still in network byte order) and - * that has to be checked. - * - * \param errbuf: a pointer to a user-allocated buffer (of size - * PCAP_ERRBUF_SIZE) that will contain the error message (in case there - * is one). The error message is "incompatible version". - * - * \return '0' if everything is fine, '-1' if some errors occurred. The - * error message is returned in the 'errbuf' variable. - */ -int -rpcap_checkver(SOCKET sock, struct rpcap_header *header, char *errbuf) -{ - /* - * This is a sample function. - * - * In the real world, you have to check the type code, - * and decide accordingly. - */ - if (header->ver != RPCAP_VERSION) - { - pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Incompatible version number: message discarded."); - - /* we already have an error, so please discard this one */ - sock_discard(sock, ntohl(header->plen), NULL, 0); - return -1; - } - - return 0; -} - -/* * This function sends a RPCAP error to our peer. * * It has to be called when the main program detects an error. @@ -185,6 +137,58 @@ rpcap_createhdr(struct rpcap_header *header, uint8 type, uint16 value, uint32 le } /* + * Convert a message type to a string containing the type name. + */ +static const char *requests[] = +{ + NULL, /* not a valid message type */ + "RPCAP_MSG_ERROR", + "RPCAP_MSG_FINDALLIF_REQ", + "RPCAP_MSG_OPEN_REQ", + "RPCAP_MSG_STARTCAP_REQ", + "RPCAP_MSG_UPDATEFILTER_REQ", + "RPCAP_MSG_CLOSE", + "RPCAP_MSG_PACKET", + "RPCAP_MSG_AUTH_REQ", + "RPCAP_MSG_STATS_REQ", + "RPCAP_MSG_ENDCAP_REQ", + "RPCAP_MSG_SETSAMPLING_REQ", +}; +#define NUM_REQ_TYPES (sizeof requests / sizeof requests[0]) + +static const char *replies[] = +{ + NULL, + NULL, /* this would be a reply to RPCAP_MSG_ERROR */ + "RPCAP_MSG_FINDALLIF_REPLY", + "RPCAP_MSG_OPEN_REPLY", + "RPCAP_MSG_STARTCAP_REPLY", + "RPCAP_MSG_UPDATEFILTER_REPLY", + NULL, /* this would be a reply to RPCAP_MSG_CLOSE */ + NULL, /* this would be a reply to RPCAP_MSG_PACKET */ + "RPCAP_MSG_AUTH_REPLY", + "RPCAP_MSG_STATS_REPLY", + "RPCAP_MSG_ENDCAP_REPLY", + "RPCAP_MSG_SETSAMPLING_REPLY", +}; +#define NUM_REPLY_TYPES (sizeof replies / sizeof replies[0]) + +const char * +rpcap_msg_type_string(uint8 type) +{ + if (type & RPCAP_MSG_IS_REPLY) { + type &= ~RPCAP_MSG_IS_REPLY; + if (type >= NUM_REPLY_TYPES) + return NULL; + return replies[type]; + } else { + if (type > NUM_REQ_TYPES) + return NULL; + return requests[type]; + } +} + +/* * This function checks whether the header of the received message is correct. * * It is a way to easily check if the message received, in a certain state @@ -240,17 +244,25 @@ rpcap_checkmsg(char *errbuf, SOCKET sock, struct rpcap_header *header, uint8 fir int32 len; char remote_errbuf[PCAP_ERRBUF_SIZE]; - va_start(ap, first); - /* Check if the present version of the protocol can handle this message */ - if (rpcap_checkver(sock, header, errbuf)) + if (header->ver != RPCAP_VERSION) { - SOCK_ASSERT(errbuf, 1); + pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Incompatible version number: message discarded."); - va_end(ap); + /* + * Discard the rest of the packet. + */ + if (sock_discard(sock, ntohl(header->plen), NULL, 0) == -1) { + /* + * Network error. + */ + return -3; + } return -1; } + va_start(ap, first); + type = first; while (type != 0) |