/* * Copyright (c) 2002 - 2003 * NetGroup, Politecnico di Torino (Italy) * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Politecnico di Torino nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifdef HAVE_CONFIG_H #include #endif #include "ftmacros.h" #include "varattrs.h" #include // for the errno variable #include // for malloc(), free(), ... #include // for strlen(), ... #include // for INT_MAX #ifdef _WIN32 #include // for threads #else #include #include #include #include // for select() and such #include // for password management #endif #ifdef HAVE_GETSPNAM #include // for password management #endif #include // for libpcap/WinPcap calls #include "fmtutils.h" #include "sockutils.h" // for socket calls #include "portability.h" #include "rpcap-protocol.h" #include "daemon.h" #include "log.h" #define RPCAP_TIMEOUT_INIT 90 /* Initial timeout for RPCAP connections (default: 90 sec) */ #define RPCAP_TIMEOUT_RUNTIME 180 /* Run-time timeout for RPCAP connections (default: 3 min) */ #define RPCAP_SUSPEND_WRONGAUTH 1 /* If the authentication is wrong, stops 1 sec before accepting a new auth message */ // Parameters for the service loop. struct daemon_slpars { SOCKET sockctrl_in; //!< SOCKET ID of the input side of the control connection SOCKET sockctrl_out; //!< SOCKET ID of the output side of the control connection uint8 protocol_version; //!< negotiated protocol version int isactive; //!< Not null if the daemon has to run in active mode int nullAuthAllowed; //!< '1' if we permit NULL authentication, '0' otherwise }; /* * Data for a session managed by a thread. */ struct session { SOCKET sockctrl_out; SOCKET sockdata; uint8 protocol_version; pcap_t *fp; unsigned int TotCapt; }; // // Structure to refer to a thread. // It includes both a Boolean indicating whether we *have* a thread, // and a platform-dependent (UN*X vs. Windows) identifier for the // thread; on Windows, we could use an invalid handle to indicate // that we don't have a thread, but there *is* no portable "no thread" // value for a pthread_t on UN*X. // struct thread_handle { int have_thread; #ifdef _WIN32 HANDLE thread; #else pthread_t thread; #endif }; // Locally defined functions static int daemon_msg_err(SOCKET sockctrl_in, uint32 plen); static int daemon_msg_auth_req(struct daemon_slpars *pars, uint32 plen); static int daemon_AuthUserPwd(char *username, char *password, char *errbuf); static int daemon_msg_findallif_req(struct daemon_slpars *pars, uint32 plen); static int daemon_msg_open_req(struct daemon_slpars *pars, uint32 plen, char *source, size_t sourcelen); static int daemon_msg_startcap_req(struct daemon_slpars *pars, uint32 plen, struct thread_handle *threaddata, char *source, struct session **sessionp, struct rpcap_sampling *samp_param); static int daemon_msg_endcap_req(struct daemon_slpars *pars, struct session *session, struct thread_handle *threaddata); static int daemon_msg_updatefilter_req(struct daemon_slpars *pars, struct session *session, uint32 plen); static int daemon_unpackapplyfilter(SOCKET sockctrl_in, struct session *session, uint32 *plenp, char *errbuf); static int daemon_msg_stats_req(struct daemon_slpars *pars, struct session *session, uint32 plen, struct pcap_stat *stats, unsigned int svrcapt); static int daemon_msg_setsampling_req(struct daemon_slpars *pars, uint32 plen, struct rpcap_sampling *samp_param); static void daemon_seraddr(struct sockaddr_storage *sockaddrin, struct rpcap_sockaddr *sockaddrout); #ifdef _WIN32 static unsigned __stdcall daemon_thrdatamain(void *ptr); #else static void *daemon_thrdatamain(void *ptr); #endif static int rpcapd_recv_msg_header(SOCKET sock, struct rpcap_header *headerp); static int rpcapd_recv(SOCKET sock, char *buffer, size_t toread, uint32 *plen, char *errmsgbuf); static int rpcapd_discard(SOCKET sock, uint32 len); int daemon_serviceloop(SOCKET sockctrl_in, SOCKET sockctrl_out, int isactive, int nullAuthAllowed) { struct daemon_slpars pars; // service loop parameters char errbuf[PCAP_ERRBUF_SIZE + 1]; // keeps the error string, prior to be printed char errmsgbuf[PCAP_ERRBUF_SIZE + 1]; // buffer for errors to send to the client int nrecv; struct rpcap_header header; // RPCAP message general header uint32 plen; // payload length from header int authenticated = 0; // 1 if the client has successfully authenticated char source[PCAP_BUF_SIZE+1]; // keeps the string that contains the interface to open int got_source = 0; // 1 if we've gotten the source from an open request struct session *session = NULL; // struct session main variable const char *msg_type_string; // string for message type int client_told_us_to_close = 0; // 1 if the client told us to close the capture struct thread_handle threaddata; // 'read from daemon and send to client' thread // needed to save the values of the statistics struct pcap_stat stats; unsigned int svrcapt; struct rpcap_sampling samp_param; // in case sampling has been requested // Structures needed for the select() call fd_set rfds; // set of socket descriptors we have to check struct timeval tv; // maximum time the select() can block waiting for data int retval; // select() return value // Set parameters structure pars.sockctrl_in = sockctrl_in; pars.sockctrl_out = sockctrl_out; pars.protocol_version = 0; // not yet known pars.isactive = isactive; // active mode pars.nullAuthAllowed = nullAuthAllowed; // We don't have a thread yet. threaddata.have_thread = 0; // // We *shouldn't* have to initialize the thread indicator // itself, because the compiler *should* realize that we // only use this if have_thread isn't 0, but we *do* have // to do it, because not all compilers *do* realize that. // // There is no "invalid thread handle" value for a UN*X // pthread_t, so we just zero it out. // #ifdef _WIN32 threaddata.thread = INVALID_HANDLE_VALUE; #else memset(&threaddata.thread, 0, sizeof(threaddata.thread)); #endif *errbuf = 0; // Initialize errbuf // // The client must first authenticate; loop until they send us a // message with a version we support and credentials we accept, // they send us a close message indicating that they're giving up, // or we get a network error or other fatal error. // while (!authenticated) { // // If we're in active mode, we have to check for the // initial timeout. // // XXX - do this on *every* trip through the loop? // if (!pars.isactive) { FD_ZERO(&rfds); // We do not have to block here tv.tv_sec = RPCAP_TIMEOUT_INIT; tv.tv_usec = 0; FD_SET(pars.sockctrl_in, &rfds); retval = select((int)pars.sockctrl_in + 1, &rfds, NULL, NULL, &tv); if (retval == -1) { sock_geterror("select failed: ", errmsgbuf, PCAP_ERRBUF_SIZE); if (rpcap_senderror(pars.sockctrl_out, 0, PCAP_ERR_NETW, errmsgbuf, errbuf) == -1) rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // The timeout has expired // So, this was a fake connection. Drop it down if (retval == 0) { if (rpcap_senderror(pars.sockctrl_out, 0, PCAP_ERR_INITTIMEOUT, "The RPCAP initial timeout has expired", errbuf) == -1) rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } } // // Read the message header from the client. // nrecv = rpcapd_recv_msg_header(pars.sockctrl_in, &header); if (nrecv == -1) { // Fatal error. goto end; } if (nrecv == -2) { // Client closed the connection. goto end; } plen = header.plen; // // Did the client specify a version we can handle? // if (!RPCAP_VERSION_IS_SUPPORTED(header.ver)) { // // Tell them it's not a valid protocol version. // uint8 reply_version; // // If RPCAP_MIN_VERSION is 0, no version is too // old, as the oldest supported version is 0, // and there are no negative versions. // #if RPCAP_MIN_VERSION != 0 if (header.ver < RPCAP_MIN_VERSION) { // // Their maximum version is too old; // there *is* no version we can both // handle, and they might reject // an error with a version they don't // understand, so reply with the // version they sent. That may // make them retry with that version, // but they'll give up on that // failure. // reply_version = header.ver; } else #endif { // // Their maximum version is too new, // but they might be able to handle // *our* maximum version, so reply // with that version. // reply_version = RPCAP_MAX_VERSION; } if (rpcap_senderror(pars.sockctrl_out, reply_version, PCAP_ERR_WRONGVER, "RPCAP version number mismatch", errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Network error. goto end; } // Let them try again. continue; } // // OK, we use the version the client specified. // pars.protocol_version = header.ver; switch (header.type) { case RPCAP_MSG_AUTH_REQ: retval = daemon_msg_auth_req(&pars, plen); if (retval == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } if (retval == -2) { // Non-fatal error; we sent back // an error message, so let them // try again. continue; } // OK, we're authenticated; we sent back // a reply, so start serving requests. authenticated = 1; break; case RPCAP_MSG_CLOSE: // // The client is giving up. // Discard the rest of the message, if // there is anything more. // (void)rpcapd_discard(pars.sockctrl_in, plen); // We're done with this client. goto end; case RPCAP_MSG_ERROR: // Log this and close the connection? // XXX - is this what happens in active // mode, where *we* initiate the // connection, and the client gives us // an error message rather than a "let // me log in" message, indicating that // we're not allowed to connect to them? (void)daemon_msg_err(pars.sockctrl_in, plen); goto end; case RPCAP_MSG_FINDALLIF_REQ: case RPCAP_MSG_OPEN_REQ: case RPCAP_MSG_STARTCAP_REQ: case RPCAP_MSG_UPDATEFILTER_REQ: case RPCAP_MSG_STATS_REQ: case RPCAP_MSG_ENDCAP_REQ: case RPCAP_MSG_SETSAMPLING_REQ: // // These requests can't be sent until // the client is authenticated. // msg_type_string = rpcap_msg_type_string(header.type); if (msg_type_string != NULL) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "%s request sent before authentication was completed", msg_type_string); } else { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Message of type %u sent before authentication was completed", header.type); } if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, errmsgbuf, errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Network error. goto end; } break; case RPCAP_MSG_PACKET: case RPCAP_MSG_FINDALLIF_REPLY: case RPCAP_MSG_OPEN_REPLY: case RPCAP_MSG_STARTCAP_REPLY: case RPCAP_MSG_UPDATEFILTER_REPLY: case RPCAP_MSG_AUTH_REPLY: case RPCAP_MSG_STATS_REPLY: case RPCAP_MSG_ENDCAP_REPLY: case RPCAP_MSG_SETSAMPLING_REPLY: // // These are server-to-client messages. // msg_type_string = rpcap_msg_type_string(header.type); if (msg_type_string != NULL) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Server-to-client message %s received from client", msg_type_string); } else { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Server-to-client message of type %u received from client", header.type); } if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, errmsgbuf, errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Fatal error. goto end; } break; default: // // Unknown message type. // pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Unknown message type %u", header.type); if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, errmsgbuf, errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Fatal error. goto end; } break; } } // // OK, the client has authenticated itself, and we can start // processing regular requests from it. // // // We don't have any statistics yet. // stats.ps_ifdrop = 0; stats.ps_recv = 0; stats.ps_drop = 0; svrcapt = 0; // // Service requests. // for (;;) { errbuf[0] = 0; // clear errbuf // Avoid zombies connections; check if the connection is opens but no commands are performed // from more than RPCAP_TIMEOUT_RUNTIME // Conditions: // - I have to be in normal mode (no active mode) // - if the device is open, I don't have to be in the middle of a capture (session->sockdata) // - if the device is closed, I have always to check if a new command arrives // // Be carefully: the capture can have been started, but an error occurred (so session != NULL, but // sockdata is 0 if ((!pars.isactive) && ((session == NULL) || ((session != NULL) && (session->sockdata == 0)))) { // Check for the initial timeout FD_ZERO(&rfds); // We do not have to block here tv.tv_sec = RPCAP_TIMEOUT_RUNTIME; tv.tv_usec = 0; FD_SET(pars.sockctrl_in, &rfds); retval = select((int)pars.sockctrl_in + 1, &rfds, NULL, NULL, &tv); if (retval == -1) { sock_geterror("select failed: ", errmsgbuf, PCAP_ERRBUF_SIZE); if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_NETW, errmsgbuf, errbuf) == -1) rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // The timeout has expired // So, this was a fake connection. Drop it down if (retval == 0) { if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_INITTIMEOUT, "The RPCAP initial timeout has expired", errbuf) == -1) rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } } // // Read the message header from the client. // nrecv = rpcapd_recv_msg_header(pars.sockctrl_in, &header); if (nrecv == -1) { // Fatal error. goto end; } if (nrecv == -2) { // Client closed the connection. goto end; } plen = header.plen; // // Did the client specify the version we negotiated? // // For now, there's only one version. // if (header.ver != pars.protocol_version) { // // Tell them it's not the negotiated version. // Send the error message with their version, // so they don't reject it as having the wrong // version. // if (rpcap_senderror(pars.sockctrl_out, header.ver, PCAP_ERR_WRONGVER, "RPCAP version in message isn't the negotiated version", errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. (void)rpcapd_discard(pars.sockctrl_in, plen); // Give up on them. goto end; } switch (header.type) { case RPCAP_MSG_ERROR: // The other endpoint reported an error { (void)daemon_msg_err(pars.sockctrl_in, plen); // Do nothing; just exit; the error code is already into the errbuf // XXX - actually exit.... break; } case RPCAP_MSG_FINDALLIF_REQ: { if (daemon_msg_findallif_req(&pars, plen) == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } break; } case RPCAP_MSG_OPEN_REQ: { // // Process the open request, and keep // the source from it, for use later // when the capture is started. // // XXX - we don't care if the client sends // us multiple open requests, the last // one wins. // retval = daemon_msg_open_req(&pars, plen, source, sizeof(source)); if (retval == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } got_source = 1; break; } case RPCAP_MSG_STARTCAP_REQ: { if (!got_source) { // They never told us what device // to capture on! if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_STARTCAPTURE, "No capture device was specified", errbuf) == -1) { // Fatal error; log an // error and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { goto end; } break; } if (daemon_msg_startcap_req(&pars, plen, &threaddata, source, &session, &samp_param) == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } break; } case RPCAP_MSG_UPDATEFILTER_REQ: { if (session) { if (daemon_msg_updatefilter_req(&pars, session, plen) == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } } else { if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_UPDATEFILTER, "Device not opened. Cannot update filter", errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } } break; } case RPCAP_MSG_CLOSE: // The other endpoint close the pcap session { // // Indicate to our caller that the client // closed the control connection. // This is used only in case of active mode. // client_told_us_to_close = 1; SOCK_DEBUG_MESSAGE("The other end system asked to close the connection."); goto end; } case RPCAP_MSG_STATS_REQ: { if (daemon_msg_stats_req(&pars, session, plen, &stats, svrcapt) == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } break; } case RPCAP_MSG_ENDCAP_REQ: // The other endpoint close the current capture session { if (session) { // Save statistics (we can need them in the future) if (pcap_stats(session->fp, &stats)) { svrcapt = session->TotCapt; } else { stats.ps_ifdrop = 0; stats.ps_recv = 0; stats.ps_drop = 0; svrcapt = 0; } if (daemon_msg_endcap_req(&pars, session, &threaddata) == -1) { free(session); session = NULL; // Fatal error; a message has // been logged, so just give up. goto end; } free(session); session = NULL; } else { rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_ENDCAPTURE, "Device not opened. Cannot close the capture", errbuf); } break; } case RPCAP_MSG_SETSAMPLING_REQ: { if (daemon_msg_setsampling_req(&pars, plen, &samp_param) == -1) { // Fatal error; a message has // been logged, so just give up. goto end; } break; } case RPCAP_MSG_AUTH_REQ: { // // We're already authenticated; you don't // get to reauthenticate. // rpcapd_log(LOGPRIO_INFO, "The client sent an RPCAP_MSG_AUTH_REQ message after authentication was completed"); if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, "RPCAP_MSG_AUTH_REQ request sent after authentication was completed", errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Fatal error. goto end; } goto end; case RPCAP_MSG_PACKET: case RPCAP_MSG_FINDALLIF_REPLY: case RPCAP_MSG_OPEN_REPLY: case RPCAP_MSG_STARTCAP_REPLY: case RPCAP_MSG_UPDATEFILTER_REPLY: case RPCAP_MSG_AUTH_REPLY: case RPCAP_MSG_STATS_REPLY: case RPCAP_MSG_ENDCAP_REPLY: case RPCAP_MSG_SETSAMPLING_REPLY: // // These are server-to-client messages. // msg_type_string = rpcap_msg_type_string(header.type); if (msg_type_string != NULL) { rpcapd_log(LOGPRIO_INFO, "The client sent a %s server-to-client message", msg_type_string); pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Server-to-client message %s received from client", msg_type_string); } else { rpcapd_log(LOGPRIO_INFO, "The client sent a server-to-client message of type %u", header.type); pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Server-to-client message of type %u received from client", header.type); } if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, errmsgbuf, errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Fatal error. goto end; } goto end; default: // // Unknown message type. // rpcapd_log(LOGPRIO_INFO, "The client sent a message of type %u", header.type); pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Unknown message type %u", header.type); if (rpcap_senderror(pars.sockctrl_out, pars.protocol_version, PCAP_ERR_WRONGMSG, errbuf, errmsgbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto end; } // Discard the rest of the message. if (rpcapd_discard(pars.sockctrl_in, plen) == -1) { // Fatal error. goto end; } goto end; } } } end: // The child thread is about to end // perform pcap_t cleanup, in case it has not been done if (session) { if (threaddata.have_thread) { #ifdef _WIN32 // // Tell the data connection thread main capture // loop to break out of that loop. // pcap_breakloop(session->fp); // // If it's currently blocked waiting for packets // to arrive, try to wake it up, so it can see // the "break out of the loop" indication. // SetEvent(pcap_getevent(session->fp)); // // Wait for the thread to exit, so we don't close // sockets out from under it. // // XXX - have a timeout, so we don't wait forever? // WaitForSingleObject(threaddata.thread, INFINITE); // // Release the thread handle, as we're done with // it. // CloseHandle(threaddata.thread); #else pthread_cancel(threaddata.thread); #endif threaddata.have_thread = 0; } if (session->sockdata) { sock_close(session->sockdata, NULL, 0); session->sockdata = 0; } pcap_close(session->fp); free(session); session = NULL; } // Print message and return SOCK_DEBUG_MESSAGE("I'm exiting from the child loop"); SOCK_DEBUG_MESSAGE(errbuf); return client_told_us_to_close; } /* * This handles the RPCAP_MSG_ERR message. */ static int daemon_msg_err(SOCKET sockctrl_in, uint32 plen) { char errbuf[PCAP_ERRBUF_SIZE]; char remote_errbuf[PCAP_ERRBUF_SIZE]; if (plen >= PCAP_ERRBUF_SIZE) { /* * Message is too long; just read as much of it as we * can into the buffer provided, and discard the rest. */ if (sock_recv(sockctrl_in, remote_errbuf, PCAP_ERRBUF_SIZE - 1, SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, PCAP_ERRBUF_SIZE) == -1) { // Network error. rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } if (rpcapd_discard(sockctrl_in, plen - (PCAP_ERRBUF_SIZE - 1)) == -1) { // Network error. return -1; } /* * Null-terminate it. */ remote_errbuf[PCAP_ERRBUF_SIZE - 1] = '\0'; } else if (plen == 0) { /* Empty error string. */ remote_errbuf[0] = '\0'; } else { if (sock_recv(sockctrl_in, remote_errbuf, plen, SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, PCAP_ERRBUF_SIZE) == -1) { // Network error. rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } /* * Null-terminate it. */ remote_errbuf[plen] = '\0'; } // Log the message rpcapd_log(LOGPRIO_ERROR, "Error from client: %s", remote_errbuf); return 0; } /* * This handles the RPCAP_MSG_AUTH_REQ message. * It checks if the authentication credentials supplied by the user are valid. * * This function is called if the daemon receives a RPCAP_MSG_AUTH_REQ * message in its authentication loop. It reads the body of the * authentication message from the network and checks whether the * credentials are valid. * * \param sockctrl: the socket for the control connection. * * \param nullAuthAllowed: '1' if the NULL authentication is allowed. * * \param errbuf: a user-allocated buffer in which the error message * (if one) has to be written. It must be at least PCAP_ERRBUF_SIZE * bytes long. * * \return '0' if everything is fine, '-1' if an unrecoverable error occurred, * or '-2' if the authentication failed. For errors, an error message is * returned in the 'errbuf' variable; this gives a message for the * unrecoverable error or for the authentication failure. */ static int daemon_msg_auth_req(struct daemon_slpars *pars, uint32 plen) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client struct rpcap_header header; // RPCAP message general header int status; struct rpcap_auth auth; // RPCAP authentication header status = rpcapd_recv(pars->sockctrl_in, (char *) &auth, sizeof(struct rpcap_auth), &plen, errmsgbuf); if (status == -1) { return -1; } if (status == -2) { goto error; } switch (ntohs(auth.type)) { case RPCAP_RMTAUTH_NULL: { if (!pars->nullAuthAllowed) { // Send the client an error reply. pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Authentication failed; NULL authentication not permitted."); goto error; } break; } case RPCAP_RMTAUTH_PWD: { char *username, *passwd; uint32 usernamelen, passwdlen; usernamelen = ntohs(auth.slen1); username = (char *) malloc (usernamelen + 1); if (username == NULL) { pcap_fmt_errmsg_for_errno(errmsgbuf, PCAP_ERRBUF_SIZE, errno, "malloc() failed"); goto error; } status = rpcapd_recv(pars->sockctrl_in, username, usernamelen, &plen, errmsgbuf); if (status == -1) { free(username); return -1; } if (status == -2) { free(username); goto error; } username[usernamelen] = '\0'; passwdlen = ntohs(auth.slen2); passwd = (char *) malloc (passwdlen + 1); if (passwd == NULL) { pcap_fmt_errmsg_for_errno(errmsgbuf, PCAP_ERRBUF_SIZE, errno, "malloc() failed"); free(username); goto error; } status = rpcapd_recv(pars->sockctrl_in, passwd, passwdlen, &plen, errmsgbuf); if (status == -1) { free(username); free(passwd); return -1; } if (status == -2) { free(username); free(passwd); goto error; } passwd[passwdlen] = '\0'; if (daemon_AuthUserPwd(username, passwd, errmsgbuf)) { // // Authentication failed. Let the client // know. // free(username); free(passwd); if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_AUTH, errmsgbuf, errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } // // Suspend for 1 second, so that they can't // hammer us with repeated tries with an // attack such as a dictionary attack. // // WARNING: this delay is inserted only // at this point; if the client closes the // connection and reconnects, the suspension // time does not have any effect. // sleep_secs(RPCAP_SUSPEND_WRONGAUTH); goto error_noreply; } free(username); free(passwd); break; } default: pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Authentication type not recognized."); goto error; } // The authentication succeeded; let the client know. rpcap_createhdr(&header, pars->protocol_version, RPCAP_MSG_AUTH_REPLY, 0, 0); // Send the ok message back if (sock_send(pars->sockctrl_out, (char *) &header, sizeof (struct rpcap_header), errbuf, PCAP_ERRBUF_SIZE) == -1) { // That failed; log a messsage and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } return 0; error: if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_AUTH, errmsgbuf, errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } error_noreply: // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } return -2; } static int daemon_AuthUserPwd(char *username, char *password, char *errbuf) { #ifdef _WIN32 /* * Warning: the user which launches the process must have the * SE_TCB_NAME right. * This corresponds to have the "Act as part of the Operating System" * turned on (administrative tools, local security settings, local * policies, user right assignment) * However, it seems to me that if you run it as a service, this * right should be provided by default. */ HANDLE Token; if (LogonUser(username, ".", password, LOGON32_LOGON_NETWORK, LOGON32_PROVIDER_DEFAULT, &Token) == 0) { int error; error = GetLastError(); FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf, PCAP_ERRBUF_SIZE, NULL); return -1; } // This call should change the current thread to the selected user. // I didn't test it. if (ImpersonateLoggedOnUser(Token) == 0) { int error; error = GetLastError(); FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf, PCAP_ERRBUF_SIZE, NULL); CloseHandle(Token); return -1; } CloseHandle(Token); return 0; #else /* * See * * http://www.unixpapa.com/incnote/passwd.html * * We use the Solaris/Linux shadow password authentication if * we have getspnam(), otherwise we just do traditional * authentication, which, on some platforms, might work, even * with shadow passwords, if we're running as root. Traditional * authenticaion won't work if we're not running as root, as * I think these days all UN*Xes either won't return the password * at all with getpwnam() or will only do so if you're root. * * XXX - perhaps what we *should* be using is PAM, if we have * it. That might hide all the details of username/password * authentication, whether it's done with a visible-to-root- * only password database or some other authentication mechanism, * behind its API. */ struct passwd *user; char *user_password; #ifdef HAVE_GETSPNAM struct spwd *usersp; #endif // This call is needed to get the uid if ((user = getpwnam(username)) == NULL) { pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: no such user"); return -1; } #ifdef HAVE_GETSPNAM // This call is needed to get the password; otherwise 'x' is returned if ((usersp = getspnam(username)) == NULL) { pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: no such user"); return -1; } user_password = usersp->sp_pwdp; #else /* * XXX - what about other platforms? * The unixpapa.com page claims this Just Works on *BSD if you're * running as root - it's from 2000, so it doesn't indicate whether * macOS (which didn't come out until 2001, under the name Mac OS * X) behaves like the *BSDs or not, and might also work on AIX. * HP-UX does something else. * * Again, hopefully PAM hides all that. */ user_password = user->pw_passwd; #endif if (strcmp(user_password, (char *) crypt(password, user_password)) != 0) { pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication failed: password incorrect"); return -1; } if (setuid(user->pw_uid)) { pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno, "setuid"); return -1; } /* if (setgid(user->pw_gid)) { pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno, "setgid"); return -1; } */ return 0; #endif } static int daemon_msg_findallif_req(struct daemon_slpars *pars, uint32 plen) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client char sendbuf[RPCAP_NETBUF_SIZE]; // temporary buffer in which data to be sent is buffered int sendbufidx = 0; // index which keeps the number of bytes currently buffered pcap_if_t *alldevs = NULL; // pointer to the header of the interface chain pcap_if_t *d; // temp pointer needed to scan the interface chain struct pcap_addr *address; // pcap structure that keeps a network address of an interface struct rpcap_findalldevs_if *findalldevs_if;// rpcap structure that packet all the data of an interface together uint16 nif = 0; // counts the number of interface listed // Discard the rest of the message; there shouldn't be any payload. if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { // Network error. return -1; } // Retrieve the device list if (pcap_findalldevs(&alldevs, errmsgbuf) == -1) goto error; if (alldevs == NULL) { if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_NOREMOTEIF, "No interfaces found! Make sure libpcap/WinPcap is properly installed" " and you have the right to access to the remote device.", errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; } // checks the number of interfaces and it computes the total length of the payload for (d = alldevs; d != NULL; d = d->next) { nif++; if (d->description) plen+= strlen(d->description); if (d->name) plen+= strlen(d->name); plen+= sizeof(struct rpcap_findalldevs_if); for (address = d->addresses; address != NULL; address = address->next) { /* * Send only IPv4 and IPv6 addresses over the wire. */ switch (address->addr->sa_family) { case AF_INET: #ifdef AF_INET6 case AF_INET6: #endif plen+= (sizeof(struct rpcap_sockaddr) * 4); break; default: break; } } } // RPCAP findalldevs command if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; rpcap_createhdr((struct rpcap_header *) sendbuf, pars->protocol_version, RPCAP_MSG_FINDALLIF_REPLY, nif, plen); // send the interface list for (d = alldevs; d != NULL; d = d->next) { uint16 lname, ldescr; findalldevs_if = (struct rpcap_findalldevs_if *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_findalldevs_if), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; memset(findalldevs_if, 0, sizeof(struct rpcap_findalldevs_if)); if (d->description) ldescr = (short) strlen(d->description); else ldescr = 0; if (d->name) lname = (short) strlen(d->name); else lname = 0; findalldevs_if->desclen = htons(ldescr); findalldevs_if->namelen = htons(lname); findalldevs_if->flags = htonl(d->flags); for (address = d->addresses; address != NULL; address = address->next) { /* * Send only IPv4 and IPv6 addresses over the wire. */ switch (address->addr->sa_family) { case AF_INET: #ifdef AF_INET6 case AF_INET6: #endif findalldevs_if->naddr++; break; default: break; } } findalldevs_if->naddr = htons(findalldevs_if->naddr); if (sock_bufferize(d->name, lname, sendbuf, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; if (sock_bufferize(d->description, ldescr, sendbuf, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; // send all addresses for (address = d->addresses; address != NULL; address = address->next) { struct rpcap_sockaddr *sockaddr; /* * Send only IPv4 and IPv6 addresses over the wire. */ switch (address->addr->sa_family) { case AF_INET: #ifdef AF_INET6 case AF_INET6: #endif sockaddr = (struct rpcap_sockaddr *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_sockaddr), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; daemon_seraddr((struct sockaddr_storage *) address->addr, sockaddr); sockaddr = (struct rpcap_sockaddr *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_sockaddr), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; daemon_seraddr((struct sockaddr_storage *) address->netmask, sockaddr); sockaddr = (struct rpcap_sockaddr *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_sockaddr), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; daemon_seraddr((struct sockaddr_storage *) address->broadaddr, sockaddr); sockaddr = (struct rpcap_sockaddr *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_sockaddr), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; daemon_seraddr((struct sockaddr_storage *) address->dstaddr, sockaddr); break; default: break; } } } // We no longer need the device list. Free it. pcap_freealldevs(alldevs); // Send a final command that says "now send it!" if (sock_send(pars->sockctrl_out, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; error: if (alldevs) pcap_freealldevs(alldevs); if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_FINDALLIF, errmsgbuf, errbuf) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; } /* \param plen: the length of the current message (needed in order to be able to discard excess data in the message, if present) */ static int daemon_msg_open_req(struct daemon_slpars *pars, uint32 plen, char *source, size_t sourcelen) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client pcap_t *fp; // pcap_t main variable int nread; char sendbuf[RPCAP_NETBUF_SIZE]; // temporary buffer in which data to be sent is buffered int sendbufidx = 0; // index which keeps the number of bytes currently buffered struct rpcap_openreply *openreply; // open reply message if (plen > sourcelen - 1) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Source string too long"); goto error; } nread = sock_recv(pars->sockctrl_in, source, plen, SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, PCAP_ERRBUF_SIZE); if (nread == -1) { rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } source[nread] = '\0'; plen -= nread; // XXX - make sure it's *not* a URL; we don't support opening // remote devices here. // Open the selected device // This is a fake open, since we do that only to get the needed parameters, then we close the device again if ((fp = pcap_open_live(source, 1500 /* fake snaplen */, 0 /* no promis */, 1000 /* fake timeout */, errmsgbuf)) == NULL) goto error; // Now, I can send a RPCAP open reply message if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; rpcap_createhdr((struct rpcap_header *) sendbuf, pars->protocol_version, RPCAP_MSG_OPEN_REPLY, 0, sizeof(struct rpcap_openreply)); openreply = (struct rpcap_openreply *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_openreply), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; memset(openreply, 0, sizeof(struct rpcap_openreply)); openreply->linktype = htonl(pcap_datalink(fp)); // We're done with the pcap_t. pcap_close(fp); // Send the reply. if (sock_send(pars->sockctrl_out, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; error: if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_OPEN, errmsgbuf, errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } return 0; } /* \param plen: the length of the current message (needed in order to be able to discard excess data in the message, if present) */ static int daemon_msg_startcap_req(struct daemon_slpars *pars, uint32 plen, struct thread_handle *threaddata, char *source, struct session **sessionp, struct rpcap_sampling *samp_param _U_) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client char portdata[PCAP_BUF_SIZE]; // temp variable needed to derive the data port char peerhost[PCAP_BUF_SIZE]; // temp variable needed to derive the host name of our peer struct session *session = NULL; // saves state of session int status; char sendbuf[RPCAP_NETBUF_SIZE]; // temporary buffer in which data to be sent is buffered int sendbufidx = 0; // index which keeps the number of bytes currently buffered // socket-related variables SOCKET sockdata = INVALID_SOCKET; // socket descriptor of the data connection struct addrinfo hints; // temp, needed to open a socket connection struct addrinfo *addrinfo; // temp, needed to open a socket connection struct sockaddr_storage saddr; // temp, needed to retrieve the network data port chosen on the local machine socklen_t saddrlen; // temp, needed to retrieve the network data port chosen on the local machine int ret; // return value from functions #ifndef _WIN32 pthread_attr_t detachedAttribute; // temp, needed to set the created thread as detached #endif // RPCAP-related variables struct rpcap_startcapreq startcapreq; // start capture request message struct rpcap_startcapreply *startcapreply; // start capture reply message int serveropen_dp; // keeps who is going to open the data connection addrinfo = NULL; status = rpcapd_recv(pars->sockctrl_in, (char *) &startcapreq, sizeof(struct rpcap_startcapreq), &plen, errmsgbuf); if (status == -1) { goto fatal_error; } if (status == -2) { goto error; } startcapreq.flags = ntohs(startcapreq.flags); // Create a session structure session = malloc(sizeof(struct session)); if (session == NULL) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Can't allocate session structure"); goto error; } // Open the selected device if ((session->fp = pcap_open_live(source, ntohl(startcapreq.snaplen), (startcapreq.flags & RPCAP_STARTCAPREQ_FLAG_PROMISC) ? 1 : 0 /* local device, other flags not needed */, ntohl(startcapreq.read_timeout), errmsgbuf)) == NULL) goto error; #if 0 // Apply sampling parameters fp->rmt_samp.method = samp_param->method; fp->rmt_samp.value = samp_param->value; #endif /* We're in active mode if: - we're using TCP, and the user wants us to be in active mode - we're using UDP */ serveropen_dp = (startcapreq.flags & RPCAP_STARTCAPREQ_FLAG_SERVEROPEN) || (startcapreq.flags & RPCAP_STARTCAPREQ_FLAG_DGRAM) || pars->isactive; /* Gets the sockaddr structure referred to the other peer in the ctrl connection We need that because: - if we're in passive mode, we need to know the address family we want to use (the same used for the ctrl socket) - if we're in active mode, we need to know the network address of the other host we want to connect to */ saddrlen = sizeof(struct sockaddr_storage); if (getpeername(pars->sockctrl_in, (struct sockaddr *) &saddr, &saddrlen) == -1) { sock_geterror("getpeername(): ", errmsgbuf, PCAP_ERRBUF_SIZE); goto error; } memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_socktype = (startcapreq.flags & RPCAP_STARTCAPREQ_FLAG_DGRAM) ? SOCK_DGRAM : SOCK_STREAM; hints.ai_family = saddr.ss_family; // Now we have to create a new socket to send packets if (serveropen_dp) // Data connection is opened by the server toward the client { pcap_snprintf(portdata, sizeof portdata, "%d", ntohs(startcapreq.portdata)); // Get the name of the other peer (needed to connect to that specific network address) if (getnameinfo((struct sockaddr *) &saddr, saddrlen, peerhost, sizeof(peerhost), NULL, 0, NI_NUMERICHOST)) { sock_geterror("getnameinfo(): ", errmsgbuf, PCAP_ERRBUF_SIZE); goto error; } if (sock_initaddress(peerhost, portdata, &hints, &addrinfo, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; if ((sockdata = sock_open(addrinfo, SOCKOPEN_CLIENT, 0, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) goto error; } else // Data connection is opened by the client toward the server { hints.ai_flags = AI_PASSIVE; // Let's the server socket pick up a free network port for us if (sock_initaddress(NULL, "0", &hints, &addrinfo, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; if ((sockdata = sock_open(addrinfo, SOCKOPEN_SERVER, 1 /* max 1 connection in queue */, errmsgbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) goto error; // get the complete sockaddr structure used in the data connection saddrlen = sizeof(struct sockaddr_storage); if (getsockname(sockdata, (struct sockaddr *) &saddr, &saddrlen) == -1) { sock_geterror("getsockname(): ", errmsgbuf, PCAP_ERRBUF_SIZE); goto error; } // Get the local port the system picked up if (getnameinfo((struct sockaddr *) &saddr, saddrlen, NULL, 0, portdata, sizeof(portdata), NI_NUMERICSERV)) { sock_geterror("getnameinfo(): ", errmsgbuf, PCAP_ERRBUF_SIZE); goto error; } } // addrinfo is no longer used freeaddrinfo(addrinfo); addrinfo = NULL; // Needed to send an error on the ctrl connection session->sockctrl_out = pars->sockctrl_out; session->protocol_version = pars->protocol_version; // Now I can set the filter ret = daemon_unpackapplyfilter(pars->sockctrl_in, session, &plen, errmsgbuf); if (ret == -1) { // Fatal error. A message has been logged; just give up. goto fatal_error; } if (ret == -2) { // Non-fatal error. Send an error message to the client. goto error; } // Now, I can send a RPCAP start capture reply message if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; rpcap_createhdr((struct rpcap_header *) sendbuf, pars->protocol_version, RPCAP_MSG_STARTCAP_REPLY, 0, sizeof(struct rpcap_startcapreply)); startcapreply = (struct rpcap_startcapreply *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_startcapreply), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; memset(startcapreply, 0, sizeof(struct rpcap_startcapreply)); startcapreply->bufsize = htonl(pcap_bufsize(session->fp)); if (!serveropen_dp) { unsigned short port = (unsigned short)strtoul(portdata,NULL,10); startcapreply->portdata = htons(port); } if (sock_send(pars->sockctrl_out, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); goto fatal_error; } if (!serveropen_dp) { SOCKET socktemp; // We need another socket, since we're going to accept() a connection // Connection creation saddrlen = sizeof(struct sockaddr_storage); socktemp = accept(sockdata, (struct sockaddr *) &saddr, &saddrlen); if (socktemp == INVALID_SOCKET) { sock_geterror("accept(): ", errbuf, PCAP_ERRBUF_SIZE); rpcapd_log(LOGPRIO_ERROR, "Accept of data connection failed: %s", errbuf); goto error; } // Now that I accepted the connection, the server socket is no longer needed sock_close(sockdata, NULL, 0); sockdata = socktemp; } session->sockdata = sockdata; // Now we have to create a new thread to receive packets #ifdef _WIN32 threaddata->thread = (HANDLE)_beginthreadex(NULL, 0, daemon_thrdatamain, (void *) session, 0, NULL); if (threaddata->thread == 0) { pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Error creating the data thread"); goto error; } #else /* GV we need this to create the thread as detached. */ /* GV otherwise, the thread handle is not destroyed */ pthread_attr_init(&detachedAttribute); pthread_attr_setdetachstate(&detachedAttribute, PTHREAD_CREATE_DETACHED); ret = pthread_create(&threaddata->thread, &detachedAttribute, daemon_thrdatamain, (void *) session); if (ret != 0) { pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, ret, "Error creating the data thread"); pthread_attr_destroy(&detachedAttribute); goto error; } pthread_attr_destroy(&detachedAttribute); #endif threaddata->have_thread = 1; // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) goto fatal_error; *sessionp = session; return 0; error: // // Not a fatal error, so send the client an error message and // keep serving client requests. // *sessionp = NULL; if (addrinfo) freeaddrinfo(addrinfo); if (threaddata->have_thread) { #ifdef _WIN32 if (session->fp) { pcap_breakloop(session->fp); SetEvent(pcap_getevent(session->fp)); } CloseHandle(threaddata->thread); #else pthread_cancel(threaddata->thread); #endif threaddata->have_thread = 0; } if (sockdata != INVALID_SOCKET) sock_close(sockdata, NULL, 0); if (session) { if (session->fp) pcap_close(session->fp); free(session); } if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_STARTCAPTURE, errmsgbuf, errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { // Network error. return -1; } return 0; fatal_error: // // Fatal network error, so don't try to communicate with // the client, just give up. // *sessionp = NULL; if (threaddata->have_thread) { #ifdef _WIN32 if (session && session->fp) { // // Tell the data connection thread main capture // loop to break out of that loop. // pcap_breakloop(session->fp); // // If it's currently blocked waiting for packets // to arrive, try to wake it up, so it can see // the "break out of the loop" indication. // SetEvent(pcap_getevent(session->fp)); } // // Wait for the thread to exit, so we don't close // sockets out from under it. // // XXX - have a timeout, so we don't wait forever? // WaitForSingleObject(threaddata->thread, INFINITE); // // Release the thread handle, as we're done with // it. // CloseHandle(threaddata->thread); #else pthread_cancel(threaddata->thread); #endif threaddata->have_thread = 0; } if (sockdata != INVALID_SOCKET) sock_close(sockdata, NULL, 0); if (session) { if (session->fp) pcap_close(session->fp); free(session); } return -1; } static int daemon_msg_endcap_req(struct daemon_slpars *pars, struct session *session, struct thread_handle *threaddata) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors struct rpcap_header header; if (threaddata->have_thread) { #ifdef _WIN32 // // Tell the data connection thread main capture loop to // break out of that loop. // pcap_breakloop(session->fp); // // If it's currently blocked waiting for packets to // arrive, try to wake it up, so it can see the "break // out of the loop" indication. // SetEvent(pcap_getevent(session->fp)); // // Wait for the thread to exit, so we don't close // sockets out from under it. // // XXX - have a timeout, so we don't wait forever? // WaitForSingleObject(threaddata->thread, INFINITE); // // Release the thread handle, as we're done with // it. // CloseHandle(threaddata->thread); #else pthread_cancel(threaddata->thread); #endif threaddata->have_thread = 0; } if (session->sockdata) { sock_close(session->sockdata, NULL, 0); session->sockdata = 0; } pcap_close(session->fp); rpcap_createhdr(&header, pars->protocol_version, RPCAP_MSG_ENDCAP_REPLY, 0, 0); if (sock_send(pars->sockctrl_out, (char *) &header, sizeof(struct rpcap_header), errbuf, PCAP_ERRBUF_SIZE) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; } static int daemon_unpackapplyfilter(SOCKET sockctrl_in, struct session *session, uint32 *plenp, char *errmsgbuf) { int status; struct rpcap_filter filter; struct rpcap_filterbpf_insn insn; struct bpf_insn *bf_insn; struct bpf_program bf_prog; unsigned int i; status = rpcapd_recv(sockctrl_in, (char *) &filter, sizeof(struct rpcap_filter), plenp, errmsgbuf); if (status == -1) { return -1; } if (status == -2) { return -2; } bf_prog.bf_len = ntohl(filter.nitems); if (ntohs(filter.filtertype) != RPCAP_UPDATEFILTER_BPF) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Only BPF/NPF filters are currently supported"); return -2; } bf_insn = (struct bpf_insn *) malloc (sizeof(struct bpf_insn) * bf_prog.bf_len); if (bf_insn == NULL) { pcap_fmt_errmsg_for_errno(errmsgbuf, PCAP_ERRBUF_SIZE, errno, "malloc() failed"); return -2; } bf_prog.bf_insns = bf_insn; for (i = 0; i < bf_prog.bf_len; i++) { status = rpcapd_recv(sockctrl_in, (char *) &insn, sizeof(struct rpcap_filterbpf_insn), plenp, errmsgbuf); if (status == -1) { return -1; } if (status == -2) { return -2; } bf_insn->code = ntohs(insn.code); bf_insn->jf = insn.jf; bf_insn->jt = insn.jt; bf_insn->k = ntohl(insn.k); bf_insn++; } // // XXX - pcap_setfilter() should do the validation for us. // if (bpf_validate(bf_prog.bf_insns, bf_prog.bf_len) == 0) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "The filter contains bogus instructions"); return -2; } if (pcap_setfilter(session->fp, &bf_prog)) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "RPCAP error: %s", pcap_geterr(session->fp)); return -2; } return 0; } static int daemon_msg_updatefilter_req(struct daemon_slpars *pars, struct session *session, uint32 plen) { char errbuf[PCAP_ERRBUF_SIZE]; char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client int ret; // status of daemon_unpackapplyfilter() struct rpcap_header header; // keeps the answer to the updatefilter command ret = daemon_unpackapplyfilter(pars->sockctrl_in, session, &plen, errmsgbuf); if (ret == -1) { // Fatal error. A message has been logged; just give up. return -1; } if (ret == -2) { // Non-fatal error. Send an error reply to the client. goto error; } // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { // Network error. return -1; } // A response is needed, otherwise the other host does not know that everything went well rpcap_createhdr(&header, pars->protocol_version, RPCAP_MSG_UPDATEFILTER_REPLY, 0, 0); if (sock_send(pars->sockctrl_out, (char *) &header, sizeof (struct rpcap_header), pcap_geterr(session->fp), PCAP_ERRBUF_SIZE)) { // That failed; log a messsage and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; error: if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_UPDATEFILTER, errmsgbuf, NULL); return 0; } /*! \brief Received the sampling parameters from remote host and it stores in the pcap_t structure. */ static int daemon_msg_setsampling_req(struct daemon_slpars *pars, uint32 plen, struct rpcap_sampling *samp_param) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; struct rpcap_header header; struct rpcap_sampling rpcap_samp; int status; status = rpcapd_recv(pars->sockctrl_in, (char *) &rpcap_samp, sizeof(struct rpcap_sampling), &plen, errmsgbuf); if (status == -1) { return -1; } if (status == -2) { goto error; } // Save these settings in the pcap_t samp_param->method = rpcap_samp.method; samp_param->value = ntohl(rpcap_samp.value); // A response is needed, otherwise the other host does not know that everything went well rpcap_createhdr(&header, pars->protocol_version, RPCAP_MSG_SETSAMPLING_REPLY, 0, 0); if (sock_send(pars->sockctrl_out, (char *) &header, sizeof (struct rpcap_header), errbuf, PCAP_ERRBUF_SIZE) == -1) { // That failed; log a messsage and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } return 0; error: if (rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_AUTH, errmsgbuf, errbuf) == -1) { // That failed; log a message and give up. rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } // Check if all the data has been read; if not, discard the data in excess if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { return -1; } return 0; } static int daemon_msg_stats_req(struct daemon_slpars *pars, struct session *session, uint32 plen, struct pcap_stat *stats, unsigned int svrcapt) { char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors char errmsgbuf[PCAP_ERRBUF_SIZE]; // buffer for errors to send to the client char sendbuf[RPCAP_NETBUF_SIZE]; // temporary buffer in which data to be sent is buffered int sendbufidx = 0; // index which keeps the number of bytes currently buffered struct rpcap_stats *netstats; // statistics sent on the network // Checks that the header does not contain other data; if so, discard it if (rpcapd_discard(pars->sockctrl_in, plen) == -1) { // Network error. return -1; } if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; rpcap_createhdr((struct rpcap_header *) sendbuf, pars->protocol_version, RPCAP_MSG_STATS_REPLY, 0, (uint16) sizeof(struct rpcap_stats)); netstats = (struct rpcap_stats *) &sendbuf[sendbufidx]; if (sock_bufferize(NULL, sizeof(struct rpcap_stats), NULL, &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errmsgbuf, PCAP_ERRBUF_SIZE) == -1) goto error; if (session && session->fp) { if (pcap_stats(session->fp, stats) == -1) { pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "%s", pcap_geterr(session->fp)); goto error; } netstats->ifdrop = htonl(stats->ps_ifdrop); netstats->ifrecv = htonl(stats->ps_recv); netstats->krnldrop = htonl(stats->ps_drop); netstats->svrcapt = htonl(session->TotCapt); } else { // We have to keep compatibility with old applications, // which ask for statistics also when the capture has // already stopped. netstats->ifdrop = htonl(stats->ps_ifdrop); netstats->ifrecv = htonl(stats->ps_recv); netstats->krnldrop = htonl(stats->ps_drop); netstats->svrcapt = htonl(svrcapt); } // Send the packet if (sock_send(pars->sockctrl_out, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "Send to client failed: %s", errbuf); return -1; } return 0; error: rpcap_senderror(pars->sockctrl_out, pars->protocol_version, PCAP_ERR_GETSTATS, errmsgbuf, NULL); return 0; } #ifdef _WIN32 static unsigned __stdcall #else static void * #endif daemon_thrdatamain(void *ptr) { char errbuf[PCAP_ERRBUF_SIZE + 1]; // error buffer struct session *session; // pointer to the struct session for this session int retval; // general variable used to keep the return value of other functions struct rpcap_pkthdr *net_pkt_header;// header of the packet struct pcap_pkthdr *pkt_header; // pointer to the buffer that contains the header of the current packet u_char *pkt_data; // pointer to the buffer that contains the current packet size_t sendbufsize; // size for the send buffer char *sendbuf; // temporary buffer in which data to be sent is buffered int sendbufidx; // index which keeps the number of bytes currently buffered int status; session = (struct session *) ptr; session->TotCapt = 0; // counter which is incremented each time a packet is received // Initialize errbuf memset(errbuf, 0, sizeof(errbuf)); // // We need a buffer large enough to hold a buffer large enough // for a maximum-size packet for this pcap_t. // if (pcap_snapshot(session->fp) < 0) { // // The snapshot length is negative. // This "should not happen". // rpcapd_log(LOGPRIO_ERROR, "Unable to allocate the buffer for this child thread: snapshot length of %d is negative", pcap_snapshot(session->fp)); sendbuf = NULL; // we can't allocate a buffer, so nothing to free goto error; } // // size_t is unsigned, and the result of pcap_snapshot() is signed; // on no platform that we support is int larger than size_t. // This means that, unless the extra information we prepend to // a maximum-sized packet is impossibly large, the sum of the // snapshot length and the size of that extra information will // fit in a size_t. // // So we don't need to make sure that sendbufsize will overflow. // // However, we *do* need to make sure its value fits in an int, // because sock_send() can't send more than INT_MAX bytes (it could // do so on 64-bit UN*Xes, but can't do so on Windows, not even // 64-bit Windows, as the send() buffer size argument is an int // in Winsock). // sendbufsize = sizeof(struct rpcap_header) + sizeof(struct rpcap_pkthdr) + pcap_snapshot(session->fp); if (sendbufsize > INT_MAX) { rpcapd_log(LOGPRIO_ERROR, "Buffer size for this child thread would be larger than %d", INT_MAX); sendbuf = NULL; // we haven't allocated a buffer, so nothing to free goto error; } sendbuf = (char *) malloc (sendbufsize); if (sendbuf == NULL) { rpcapd_log(LOGPRIO_ERROR, "Unable to allocate the buffer for this child thread"); goto error; } #ifndef _WIN32 // Modify thread params so that it can be killed at any time retval = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); if (retval != 0) { pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, retval, "pthread_setcancelstate"); rpcapd_log(LOGPRIO_ERROR, "Can't set cancel state on data thread: %s", errbuf); goto error; } retval = pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL); if (retval != 0) { pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, retval, "pthread_setcanceltype"); rpcapd_log(LOGPRIO_ERROR, "Can't set cancel type on data thread: %s", errbuf); goto error; } #endif // Retrieve the packets while ((retval = pcap_next_ex(session->fp, &pkt_header, (const u_char **) &pkt_data)) >= 0) // cast to avoid a compiler warning { if (retval == 0) // Read timeout elapsed continue; sendbufidx = 0; // Bufferize the general header if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, (int)sendbufsize, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "sock_bufferize() error sending packet message: %s", errbuf); goto error; } rpcap_createhdr((struct rpcap_header *) sendbuf, session->protocol_version, RPCAP_MSG_PACKET, 0, (uint16) (sizeof(struct rpcap_pkthdr) + pkt_header->caplen)); net_pkt_header = (struct rpcap_pkthdr *) &sendbuf[sendbufidx]; // Bufferize the pkt header if (sock_bufferize(NULL, sizeof(struct rpcap_pkthdr), NULL, &sendbufidx, (int)sendbufsize, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "sock_bufferize() error sending packet message: %s", errbuf); goto error; } net_pkt_header->caplen = htonl(pkt_header->caplen); net_pkt_header->len = htonl(pkt_header->len); net_pkt_header->npkt = htonl(++(session->TotCapt)); // // This protocol needs to be updated with a new version // before 2038-01-19 03:14:07 UTC. // net_pkt_header->timestamp_sec = htonl((uint32)pkt_header->ts.tv_sec); net_pkt_header->timestamp_usec = htonl((uint32)pkt_header->ts.tv_usec); // Bufferize the pkt data if (sock_bufferize((char *) pkt_data, pkt_header->caplen, sendbuf, &sendbufidx, (int)sendbufsize, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE) == -1) { rpcapd_log(LOGPRIO_ERROR, "sock_bufferize() error sending packet message: %s", errbuf); goto error; } // Send the packet // If the client dropped the connection, don't report an // error, just quit. status = sock_send(session->sockdata, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE); if (status < 0) { if (status == -1) { // // Error other than "client closed the // connection out from under us"; report // it. // rpcapd_log(LOGPRIO_ERROR, "Send of packet to client failed: %s", errbuf); } // // Give up in either case. // goto error; } } if (retval == -1) { pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Error reading the packets: %s", pcap_geterr(session->fp)); rpcap_senderror(session->sockctrl_out, session->protocol_version, PCAP_ERR_READEX, errbuf, NULL); goto error; } error: closesocket(session->sockdata); session->sockdata = 0; free(sendbuf); return 0; } /*! \brief It serializes a network address. It accepts a 'sockaddr_storage' structure as input, and it converts it appropriately into a format that can be used to be sent on the network. Basically, it applies all the hton() conversion required to the input variable. \param sockaddrin a 'sockaddr_storage' pointer to the variable that has to be serialized. This variable can be both a 'sockaddr_in' and 'sockaddr_in6'. \param sockaddrout an 'rpcap_sockaddr' pointer to the variable that will contain the serialized data. This variable has to be allocated by the user. \warning This function supports only AF_INET and AF_INET6 address families. */ static void daemon_seraddr(struct sockaddr_storage *sockaddrin, struct rpcap_sockaddr *sockaddrout) { memset(sockaddrout, 0, sizeof(struct sockaddr_storage)); // There can be the case in which the sockaddrin is not available if (sockaddrin == NULL) return; // Warning: we support only AF_INET and AF_INET6 switch (sockaddrin->ss_family) { case AF_INET: { struct sockaddr_in *sockaddrin_ipv4; struct rpcap_sockaddr_in *sockaddrout_ipv4; sockaddrin_ipv4 = (struct sockaddr_in *) sockaddrin; sockaddrout_ipv4 = (struct rpcap_sockaddr_in *) sockaddrout; sockaddrout_ipv4->family = htons(RPCAP_AF_INET); sockaddrout_ipv4->port = htons(sockaddrin_ipv4->sin_port); memcpy(&sockaddrout_ipv4->addr, &sockaddrin_ipv4->sin_addr, sizeof(sockaddrout_ipv4->addr)); memset(sockaddrout_ipv4->zero, 0, sizeof(sockaddrout_ipv4->zero)); break; } #ifdef AF_INET6 case AF_INET6: { struct sockaddr_in6 *sockaddrin_ipv6; struct rpcap_sockaddr_in6 *sockaddrout_ipv6; sockaddrin_ipv6 = (struct sockaddr_in6 *) sockaddrin; sockaddrout_ipv6 = (struct rpcap_sockaddr_in6 *) sockaddrout; sockaddrout_ipv6->family = htons(RPCAP_AF_INET6); sockaddrout_ipv6->port = htons(sockaddrin_ipv6->sin6_port); sockaddrout_ipv6->flowinfo = htonl(sockaddrin_ipv6->sin6_flowinfo); memcpy(&sockaddrout_ipv6->addr, &sockaddrin_ipv6->sin6_addr, sizeof(sockaddrout_ipv6->addr)); sockaddrout_ipv6->scope_id = htonl(sockaddrin_ipv6->sin6_scope_id); break; } #endif } } /*! \brief Suspends a thread for secs seconds. */ void sleep_secs(int secs) { #ifdef _WIN32 Sleep(secs*1000); #else unsigned secs_remaining; if (secs <= 0) return; secs_remaining = secs; while (secs_remaining != 0) secs_remaining = sleep(secs_remaining); #endif } /* * Read the header of a message. */ static int rpcapd_recv_msg_header(SOCKET sock, struct rpcap_header *headerp) { int nread; char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors nread = sock_recv(sock, (char *) headerp, sizeof(struct rpcap_header), SOCK_RECEIVEALL_YES|SOCK_EOF_ISNT_ERROR, errbuf, PCAP_ERRBUF_SIZE); if (nread == -1) { // Network error. rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } if (nread == 0) { // Immediate EOF; that's treated like a close message. return -2; } headerp->plen = ntohl(headerp->plen); return 0; } /* * Read data from a message. * If we're trying to read more data that remains, puts an error * message into errmsgbuf and returns -2. Otherwise, tries to read * the data and, if that succeeds, subtracts the amount read from * the number of bytes of data that remains. * Returns 0 on success, logs a message and returns -1 on a network * error. */ static int rpcapd_recv(SOCKET sock, char *buffer, size_t toread, uint32 *plen, char *errmsgbuf) { int nread; char errbuf[PCAP_ERRBUF_SIZE]; // buffer for network errors if (toread > *plen) { // Tell the client and continue. pcap_snprintf(errmsgbuf, PCAP_ERRBUF_SIZE, "Message payload is too short"); return -2; } nread = sock_recv(sock, buffer, toread, SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, PCAP_ERRBUF_SIZE); if (nread == -1) { rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } *plen -= nread; return 0; } /* * Discard data from a connection. * Mostly used to discard wrong-sized messages. * Returns 0 on success, logs a message and returns -1 on a network * error. */ static int rpcapd_discard(SOCKET sock, uint32 len) { char errbuf[PCAP_ERRBUF_SIZE + 1]; // keeps the error string, prior to be printed if (len != 0) { if (sock_discard(sock, len, errbuf, PCAP_ERRBUF_SIZE) == -1) { // Network error. rpcapd_log(LOGPRIO_ERROR, "Read from client failed: %s", errbuf); return -1; } } return 0; }