Mercurial > dropbear
diff remotetcpfwd.c @ 4:fe6bca95afa7
Makefile.in contains updated files required
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 01 Jun 2004 02:46:09 +0000 |
parents | |
children | 425ed5c20157 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/remotetcpfwd.c Tue Jun 01 02:46:09 2004 +0000 @@ -0,0 +1,301 @@ +#include "includes.h" +#include "ssh.h" +#include "remotetcpfwd.h" +#include "dbutil.h" +#include "session.h" +#include "buffer.h" +#include "packet.h" +#include "tcpfwd.h" + +#ifndef DISABLE_REMOTETCPFWD + +struct RemoteTCP { + + unsigned char* addr; + unsigned int port; + +}; + +static void send_msg_request_success(); +static void send_msg_request_failure(); +static int cancelremotetcp(); +static int remotetcpreq(); +static int newlistener(unsigned char* bindaddr, unsigned int port); +static void acceptremote(struct TCPListener *listener); + +/* At the moment this is completely used for tcp code (with the name reflecting + * that). If new request types are added, this should be replaced with code + * similar to the request-switching in chansession.c */ +void recv_msg_global_request_remotetcp() { + + unsigned char* reqname = NULL; + unsigned int namelen; + unsigned int wantreply = 0; + int ret = DROPBEAR_FAILURE; + + TRACE(("enter recv_msg_global_request_remotetcp")); + + if (ses.opts->noremotetcp) { + TRACE(("leave recv_msg_global_request_remotetcp: remote tcp forwarding disabled")); + goto out; + } + + reqname = buf_getstring(ses.payload, &namelen); + wantreply = buf_getbyte(ses.payload); + + if (namelen > MAXNAMLEN) { + TRACE(("name len is wrong: %d", namelen)); + goto out; + } + + if (strcmp("tcpip-forward", reqname) == 0) { + ret = remotetcpreq(); + } else if (strcmp("cancel-tcpip-forward", reqname) == 0) { + ret = cancelremotetcp(); + } else { + TRACE(("reqname isn't tcpip-forward: '%s'", reqname)); + } + +out: + if (wantreply) { + if (ret == DROPBEAR_SUCCESS) { + send_msg_request_success(); + } else { + send_msg_request_failure(); + } + } + + m_free(reqname); + + TRACE(("leave recv_msg_global_request")); +} + +static void acceptremote(struct TCPListener *listener) { + + int fd; + struct sockaddr addr; + int len; + char ipstring[NI_MAXHOST], portstring[NI_MAXSERV]; + struct RemoteTCP *tcpinfo = (struct RemoteTCP*)(listener->typedata); + + len = sizeof(addr); + + fd = accept(listener->sock, &addr, &len); + if (fd < 0) { + return; + } + + if (getnameinfo(&addr, len, ipstring, sizeof(ipstring), portstring, + sizeof(portstring), NI_NUMERICHOST | NI_NUMERICSERV) != 0) { + return; + } + + if (send_msg_channel_open_init(fd, CHANNEL_ID_TCPFORWARDED, + "forwarded-tcpip") == DROPBEAR_SUCCESS) { + buf_putstring(ses.writepayload, tcpinfo->addr, + strlen(tcpinfo->addr)); + buf_putint(ses.writepayload, tcpinfo->port); + buf_putstring(ses.writepayload, ipstring, strlen(ipstring)); + buf_putint(ses.writepayload, atol(portstring)); + encrypt_packet(); + } +} + +static void cleanupremote(struct TCPListener *listener) { + + struct RemoteTCP *tcpinfo = (struct RemoteTCP*)(listener->typedata); + + m_free(tcpinfo->addr); + m_free(tcpinfo); +} + +static void send_msg_request_success() { + + CHECKCLEARTOWRITE(); + buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_SUCCESS); + encrypt_packet(); + +} + +static void send_msg_request_failure() { + + CHECKCLEARTOWRITE(); + buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_FAILURE); + encrypt_packet(); + +} + +static int matchtcp(void* typedata1, void* typedata2) { + + const struct RemoteTCP *info1 = (struct RemoteTCP*)typedata1; + const struct RemoteTCP *info2 = (struct RemoteTCP*)typedata2; + + return info1->port == info2->port + && (strcmp(info1->addr, info2->addr) == 0); +} + +static int cancelremotetcp() { + + int ret = DROPBEAR_FAILURE; + unsigned char * bindaddr = NULL; + unsigned int addrlen; + unsigned int port; + struct TCPListener * listener = NULL; + struct RemoteTCP tcpinfo; + + TRACE(("enter cancelremotetcp")); + + bindaddr = buf_getstring(ses.payload, &addrlen); + if (addrlen > MAX_IP_LEN) { + TRACE(("addr len too long: %d", addrlen)); + goto out; + } + + port = buf_getint(ses.payload); + + tcpinfo.addr = bindaddr; + tcpinfo.port = port; + listener = get_listener(CHANNEL_ID_TCPFORWARDED, &tcpinfo, matchtcp); + if (listener) { + remove_listener( listener ); + ret = DROPBEAR_SUCCESS; + } + +out: + m_free(bindaddr); + TRACE(("leave cancelremotetcp")); + return ret; +} + +static int remotetcpreq() { + + int ret = DROPBEAR_FAILURE; + unsigned char * bindaddr = NULL; + unsigned int addrlen; + unsigned int port; + + TRACE(("enter remotetcpreq")); + + bindaddr = buf_getstring(ses.payload, &addrlen); + if (addrlen > MAX_IP_LEN) { + TRACE(("addr len too long: %d", addrlen)); + goto out; + } + + port = buf_getint(ses.payload); + + if (port == 0) { + dropbear_log(LOG_INFO, "Server chosen tcpfwd ports are unsupported"); + goto out; + } + + if (port < 1 || port > 65535) { + TRACE(("invalid port: %d", port)); + goto out; + } + + /* XXX matt - server change + if (ses.authstate.pw->pw_uid != 0 + && port < IPPORT_RESERVED) { + TRACE(("can't assign port < 1024 for non-root")); + goto out; + } + */ + + ret = newlistener(bindaddr, port); + +out: + if (ret == DROPBEAR_FAILURE) { + /* we only free it if a listener wasn't created, since the listener + * has to remember it if it's to be cancelled */ + m_free(bindaddr); + } + TRACE(("leave remotetcpreq")); + return ret; +} + +static int newlistener(unsigned char* bindaddr, unsigned int port) { + + struct RemoteTCP * tcpinfo = NULL; + char portstring[6]; /* "65535\0" */ + struct addrinfo *res = NULL, *ai = NULL; + struct addrinfo hints; + int sock = -1; + int ret = DROPBEAR_FAILURE; + + TRACE(("enter newlistener")); + + /* first we try to bind, so don't need to do so much cleanup on failure */ + snprintf(portstring, sizeof(portstring), "%d", port); + memset(&hints, 0x0, sizeof(hints)); + hints.ai_socktype = SOCK_STREAM; + hints.ai_family = PF_INET; + hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST; + + if (getaddrinfo(bindaddr, portstring, &hints, &res) < 0) { + TRACE(("leave newlistener: getaddrinfo failed: %s", + strerror(errno))); + goto done; + } + + /* find the first one which works */ + for (ai = res; ai != NULL; ai = ai->ai_next) { + if (ai->ai_family != PF_INET && ai->ai_family != PF_INET6) { + continue; + } + + sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (sock < 0) { + TRACE(("socket failed: %s", strerror(errno))); + goto fail; + } + + if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { + TRACE(("bind failed: %s", strerror(errno))); + goto fail; + } + + if (listen(sock, 20) < 0) { + TRACE(("listen failed: %s", strerror(errno))); + goto fail; + } + + if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) { + TRACE(("fcntl nonblocking failed: %s", strerror(errno))); + goto fail; + } + + /* success */ + break; + +fail: + close(sock); + } + + + if (ai == NULL) { + TRACE(("no successful sockets")); + goto done; + } + + tcpinfo = (struct RemoteTCP*)m_malloc(sizeof(struct RemoteTCP)); + tcpinfo->addr = bindaddr; + tcpinfo->port = port; + + ret = new_fwd(sock, CHANNEL_ID_TCPFORWARDED, tcpinfo, + acceptremote, cleanupremote); + + if (ret == DROPBEAR_FAILURE) { + m_free(tcpinfo); + } + +done: + if (res) { + freeaddrinfo(res); + } + + TRACE(("leave newlistener")); + return ret; +} + +#endif /* DISABLE_REMOTETCPFWD */