/* * ZeroTier One - Network Virtualization Everywhere * Copyright (C) 2011-2015 ZeroTier, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . * * -- * * ZeroTier may be used and distributed under the terms of the GPLv3, which * are available at: http://www.gnu.org/licenses/gpl-3.0.html * * If you would like to embed ZeroTier into a commercial application or * redistribute it in a modified binary form, please contact ZeroTier Networks * LLC. Start here: http://www.zerotier.com/ */ #ifdef USE_GNU_SOURCE #define _GNU_SOURCE #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "Intercept.h" #include "common.inc.c" #ifdef CHECKS #include #include /* for NPROTO */ #define SOCK_MAX (SOCK_PACKET + 1) #define SOCK_TYPE_MASK 0xf #endif /* Global Declarations */ static int (*realconnect)(CONNECT_SIG); static int (*realbind)(BIND_SIG); static int (*realaccept)(ACCEPT_SIG); static int (*reallisten)(LISTEN_SIG); static int (*realsocket)(SOCKET_SIG); static int (*realsetsockopt)(SETSOCKOPT_SIG); static int (*realgetsockopt)(GETSOCKOPT_SIG); static int (*realaccept4)(ACCEPT4_SIG); static long (*realsyscall)(SYSCALL_SIG); static int (*realclose)(CLOSE_SIG); static int (*realclone)(CLONE_SIG); static int (*realdup2)(DUP2_SIG); static int (*realdup3)(DUP3_SIG); static int (*realgetsockname)(GETSOCKNAME_SIG); /* Exported Function Prototypes */ void my_init(void); int connect(CONNECT_SIG); int bind(BIND_SIG); int accept(ACCEPT_SIG); int listen(LISTEN_SIG); int socket(SOCKET_SIG); int setsockopt(SETSOCKOPT_SIG); int getsockopt(GETSOCKOPT_SIG); int accept4(ACCEPT4_SIG); long syscall(SYSCALL_SIG); int close(CLOSE_SIG); int clone(CLONE_SIG); int dup2(DUP2_SIG); int dup3(DUP3_SIG); int getsockname(GETSOCKNAME_SIG); static int init_service_connection(); static void load_symbols(void); static void set_up_intercept(); #define SERVICE_CONNECT_ATTEMPTS 30 #define RPC_FD 1023 static pthread_mutex_t lock; static ssize_t sock_fd_read(int sock, void *buf, ssize_t bufsize, int *fd); void handle_error(char *name, char *info, int err) { #ifdef ERRORS_ARE_FATAL if(err < 0) { dwr(MSG_DEBUG,"handle_error(%s)=%d: FATAL: %s\n", name, err, info); exit(-1); } #endif #ifdef VERBOSE dwr(MSG_DEBUG,"%s()=%d\n", name, err); #endif } /*------------------------------------------------------------------------------ ------------------- Intercept<--->Service Comm mechanisms----------------------- ------------------------------------------------------------------------------*/ static int is_initialized = 0; static int fdret_sock; /* used for fd-transfers */ static int newfd; /* used for "this_end" socket */ static int thispid = -1; static int instance_count = 0; /* * Check for forking */ static void checkpid() { /* Do noting if not configured (sanity check -- should never get here in this case) */ if (!getenv("ZT_NC_NETWORK")) return; if (thispid != getpid()) { dwr(MSG_DEBUG, "checkpid(): clone/fork detected. Re-initializing this instance.\n"); set_up_intercept(); fdret_sock = init_service_connection(); thispid = getpid(); } } /* * Reads a return value from the service and sets errno (if applicable) */ static int get_retval() { dwr(MSG_DEBUG,"get_retval()\n"); if(fdret_sock >= 0) { int retval; int sz = sizeof(char) + sizeof(retval) + sizeof(errno); char retbuf[BUF_SZ]; memset(&retbuf, '\0', sz); int n_read = read(fdret_sock, &retbuf, sz); if(n_read > 0) { memcpy(&retval, &retbuf[1], sizeof(retval)); memcpy(&errno, &retbuf[1+sizeof(retval)], sizeof(errno)); dwr(MSG_DEBUG, "get_retval(): ret = %d\n", retval); return retval; } } dwr(MSG_DEBUG,"unable to read return value\n"); return -1; } /* Reads a new file descriptor from the service */ static int get_new_fd(int oversock) { char buf[BUF_SZ]; int newfd; ssize_t size = sock_fd_read(oversock, buf, sizeof(buf), &newfd); if(size > 0){ dwr(MSG_DEBUG, "get_new_fd(): RX: fd = (%d) over (%d)\n", newfd, oversock); return newfd; } dwr(MSG_ERROR, "get_new_fd(): ERROR: unable to read fd over (%d)\n", oversock); return -1; } #ifdef VERBOSE static unsigned long rpc_count = 0; #endif /* Sends an RPC command to the service */ static int send_cmd(int rpc_fd, char *cmd) { pthread_mutex_lock(&lock); char metabuf[BUF_SZ]; // portion of buffer which contains RPC metadata for debugging #ifdef VERBOSE /* #define IDX_PID 0 #define IDX_TID sizeof(pid_t) #define IDX_COUNT IDX_TID + sizeof(pid_t) #define IDX_TIME IDX_COUNT + sizeof(int) #define IDX_CMD IDX_TIME + 20 // 20 being the length of the timestamp string #define IDX_PAYLOAD IDX_TIME + sizeof(char) */ /* [pid_t] [pid_t] [rpc_count] [int] [...] */ memset(metabuf, '\0', BUF_SZ); pid_t pid = syscall(SYS_getpid); pid_t tid = syscall(SYS_gettid); rpc_count++; char timestring[20]; time_t timestamp; timestamp = time(NULL); strftime(timestring, sizeof(timestring), "%H:%M:%S", localtime(×tamp)); memcpy(&metabuf[IDX_PID], &pid, sizeof(pid_t) ); /* pid */ memcpy(&metabuf[IDX_TID], &tid, sizeof(pid_t) ); /* tid */ memcpy(&metabuf[IDX_COUNT], &rpc_count, sizeof(rpc_count) ); /* rpc_count */ memcpy(&metabuf[IDX_TIME], ×tring, 20 ); /* timestamp */ #endif /* Combine command flag+payload with RPC metadata */ memcpy(&metabuf[IDX_PAYLOAD], cmd, PAYLOAD_SZ); int n_write = write(rpc_fd, &metabuf, BUF_SZ); if(n_write < 0){ dwr(MSG_DEBUG,"Error writing command to service (CMD = %d)\n", cmd[0]); errno = 0; } int ret = ERR_OK; if(n_write > 0) { if(cmd[0]==RPC_SOCKET) { ret = get_new_fd(fdret_sock); } if(cmd[0]==RPC_MAP_REQ || cmd[0]==RPC_CONNECT || cmd[0]==RPC_BIND || cmd[0]==RPC_LISTEN || cmd[0]==RPC_MAP) { ret = get_retval(); } if(cmd[0]==RPC_GETSOCKNAME) { ret = n_write; } } else { ret = -1; } pthread_mutex_unlock(&lock); return ret; } /* Check whether the socket is mapped to the service or not. We need to know if this is a regular AF_LOCAL socket or an end of a socketpair that the service uses. We don't want to keep state in the intercept, so we simply ask the service via an RPC */ static int is_mapped_to_service(int sockfd) { dwr(MSG_DEBUG,"is_mapped_to_service()\n"); char cmd[BUF_SZ]; memset(cmd, '\0', BUF_SZ); cmd[0] = RPC_MAP_REQ; memcpy(&cmd[1], &sockfd, sizeof(sockfd)); return send_cmd(fdret_sock, cmd); } /*------------------------------------------------------------------------------ ---------- Unix-domain socket lazy initializer (for fd-transfers)-------------- ------------------------------------------------------------------------------*/ /* Sets up the connection pipes and sockets to the service */ static int init_service_connection() { struct sockaddr_un addr; int tfd = -1, attempts = 0, conn_err = -1; const char *network_id; char af_sock_name[1024]; network_id = getenv("ZT_NC_NETWORK"); if (!network_id) return -1; strncpy(af_sock_name,network_id,sizeof(af_sock_name)); instance_count++; dwr(MSG_DEBUG,"init_service_connection()\n"); memset(&addr, 0, sizeof(addr)); addr.sun_family = AF_UNIX; strncpy(addr.sun_path, af_sock_name, sizeof(addr.sun_path)-1); if((tfd = realsocket(AF_UNIX, SOCK_STREAM, 0)) == -1) return -1; while(conn_err < 0 && attempts < SERVICE_CONNECT_ATTEMPTS) { conn_err = realconnect(tfd, (struct sockaddr*)&addr, sizeof(addr)); if(conn_err < 0) { dwr(MSG_DEBUG,"re-attempting connection in %ds\n", 1+attempts); sleep(1); } else { dwr(MSG_DEBUG,"AF_UNIX connection established: %d\n", tfd); is_initialized = 1; int newtfd = realdup2(tfd, RPC_FD-instance_count); dwr(MSG_DEBUG,"dup'd to rpc_fd = %d\n", newtfd); close(tfd); return newtfd; } attempts++; } return -1; } /*------------------------------------------------------------------------------ ------------------------ ctors and dtors (and friends)------------------------- ------------------------------------------------------------------------------*/ static void my_dest(void) __attribute__ ((destructor)); static void my_dest(void) { dwr(MSG_DEBUG,"closing connections to service...\n"); pthread_mutex_destroy(&lock); } static void load_symbols(void) { if(thispid == getpid()) { dwr(MSG_DEBUG,"detected duplicate call to global constructor (pid=%d).\n", thispid); } thispid = getpid(); realconnect = dlsym(RTLD_NEXT, "connect"); realbind = dlsym(RTLD_NEXT, "bind"); realaccept = dlsym(RTLD_NEXT, "accept"); reallisten = dlsym(RTLD_NEXT, "listen"); realsocket = dlsym(RTLD_NEXT, "socket"); realbind = dlsym(RTLD_NEXT, "bind"); realsetsockopt = dlsym(RTLD_NEXT, "setsockopt"); realgetsockopt = dlsym(RTLD_NEXT, "getsockopt"); realaccept4 = dlsym(RTLD_NEXT, "accept4"); realclone = dlsym(RTLD_NEXT, "clone"); realclose = dlsym(RTLD_NEXT, "close"); realsyscall = dlsym(RTLD_NEXT, "syscall"); realdup2 = dlsym(RTLD_NEXT, "dup2"); realdup3 = dlsym(RTLD_NEXT, "dup3"); realgetsockname = dlsym(RTLD_NEXT, "getsockname"); } /* Private Function Prototypes */ static void _init(void) __attribute__ ((constructor)); static void _init(void) { set_up_intercept(); } /* get symbols and initialize mutexes */ static void set_up_intercept() { if (!getenv("ZT_NC_NETWORK")) return; /* Hook/intercept Posix net API symbols */ load_symbols(); if(pthread_mutex_init(&lock, NULL) != 0) { dwr(MSG_ERROR, "error while initializing service call mutex\n"); } if(pthread_mutex_init(&loglock, NULL) != 0) { dwr(MSG_ERROR, "error while initializing log mutex mutex\n"); } } /*------------------------------------------------------------------------------ --------------------------------- setsockopt() --------------------------------- ------------------------------------------------------------------------------*/ /* int socket, int level, int option_name, const void *option_value, socklen_t option_len */ int setsockopt(SETSOCKOPT_SIG) { if(realsetsockopt == NULL){ dwr(MSG_ERROR, "setsockopt(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"setsockopt(%d)\n", socket); /* if(is_mapped_to_service(socket) < 0) { // First, check if the service manages this return realsetsockopt(socket, level, option_name, option_value, option_len); } */ /* return(realsetsockopt(socket, level, option_name, option_value, option_len)); */ if(level == SOL_IPV6 && option_name == IPV6_V6ONLY) return 0; if(level == SOL_IP && option_name == IP_TTL) return 0; if(level == IPPROTO_TCP || (level == SOL_SOCKET && option_name == SO_KEEPALIVE)) return 0; /* make sure we don't touch any standard outputs */ if(socket == STDIN_FILENO || socket == STDOUT_FILENO || socket == STDERR_FILENO) return(realsetsockopt(socket, level, option_name, option_value, option_len)); int err = realsetsockopt(socket, level, option_name, option_value, option_len); if(err < 0){ perror("setsockopt():\n"); } return 0; } /*------------------------------------------------------------------------------ --------------------------------- getsockopt() --------------------------------- ------------------------------------------------------------------------------*/ /* int sockfd, int level, int optname, void *optval, socklen_t *optlen */ int getsockopt(GETSOCKOPT_SIG) { if(realgetsockopt == NULL){ dwr(MSG_ERROR, "getsockopt(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"getsockopt(%d)\n", sockfd); if(is_mapped_to_service(sockfd) <= 0) { // First, check if the service manages this return realgetsockopt(sockfd, level, optname, optval, optlen); } //return 0; //int err = realgetsockopt(sockfd, level, optname, optval, optlen); /* TODO: this condition will need a little more intelligence later on -- we will need to know if this fd is a local we are spoofing, or a true local */ if(optname == SO_TYPE) { int* val = (int*)optval; *val = 2; optval = (void*)val; } /* if(err < 0){ perror("getsockopt():\n"); } */ return 0; } /*------------------------------------------------------------------------------ ----------------------------------- socket() ----------------------------------- ------------------------------------------------------------------------------*/ /* int socket_family, int socket_type, int protocol socket() intercept function */ int socket(SOCKET_SIG) { if(realsocket == NULL){ dwr(MSG_ERROR, "socket(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"socket():\n"); int err; #ifdef CHECKS /* Check that type makes sense */ int flags = socket_type & ~SOCK_TYPE_MASK; if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) { errno = EINVAL; handle_error("socket", "", -1); return -1; } socket_type &= SOCK_TYPE_MASK; /* Check protocol is in range */ if (socket_family < 0 || socket_family >= NPROTO){ errno = EAFNOSUPPORT; handle_error("socket", "", -1); return -1; } if (socket_type < 0 || socket_type >= SOCK_MAX) { errno = EINVAL; handle_error("socket", "", -1); return -1; } /* Check that we haven't hit the soft-limit file descriptors allowed */ /* FIXME: Find number of open fds struct rlimit rl; getrlimit(RLIMIT_NOFILE, &rl); if(sockfd >= rl.rlim_cur){ errno = EMFILE; return -1; } */ /* TODO: detect ENFILE condition */ #endif char cmd[BUF_SZ]; fdret_sock = !is_initialized ? init_service_connection() : fdret_sock; if(fdret_sock < 0) { dwr(MSG_DEBUG,"BAD service connection. exiting.\n"); handle_error("socket", "", -1); exit(-1); } if(socket_family == AF_LOCAL || socket_family == AF_NETLINK || socket_family == AF_UNIX) { int err = realsocket(socket_family, socket_type, protocol); dwr(MSG_DEBUG,"realsocket, err = %d\n", err); handle_error("socket", "", err); return err; } /* Assemble and send RPC */ struct socket_st rpc_st; rpc_st.socket_family = socket_family; rpc_st.socket_type = socket_type; rpc_st.protocol = protocol; rpc_st.__tid = syscall(SYS_gettid); memset(cmd, '\0', BUF_SZ); cmd[0] = RPC_SOCKET; memcpy(&cmd[1], &rpc_st, sizeof(struct socket_st)); /* send command and get new fd */ newfd = send_cmd(fdret_sock, cmd); if(newfd > 0) { dwr(MSG_DEBUG,"sending fd = %d to Service over (%d)\n", newfd, fdret_sock); /* send our local-fd number back to service so it can complete its mapping table entry */ memset(cmd, '\0', BUF_SZ); cmd[0] = RPC_MAP; memcpy(&cmd[1], &newfd, sizeof(newfd)); /* send fd mapping and get confirmation */ err = send_cmd(fdret_sock, cmd); if(err > -1) { errno = ERR_OK; dwr(MSG_DEBUG, "RXd fd confirmation. Mapped!\n"); return newfd; /* Mapping complete, everything is OK */ } else{ dwr(MSG_DEBUG,"Error, service sent bad fd.\n"); return err; /* Mapping failed */ } } else { dwr(MSG_DEBUG,"Error while receiving new fd.\n"); return newfd; } } /*------------------------------------------------------------------------------ ---------------------------------- connect() ----------------------------------- ------------------------------------------------------------------------------*/ /* int __fd, const struct sockaddr * __addr, socklen_t __len connect() intercept function */ int connect(CONNECT_SIG) { if(realconnect == NULL){ dwr(MSG_ERROR, "connect(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"connect(%d):\n", __fd); /* print_addr(__addr); */ struct sockaddr_in *connaddr; connaddr = (struct sockaddr_in *) __addr; #ifdef CHECKS /* Check that this is a valid fd */ if(fcntl(__fd, F_GETFD) < 0) { errno = EBADF; handle_error("connect", "EBADF", -1); return -1; } /* Check that it is a socket */ int sock_type; socklen_t sock_type_len = sizeof(sock_type); if(getsockopt(__fd, SOL_SOCKET, SO_TYPE, (void *) &sock_type, &sock_type_len) < 0) { errno = ENOTSOCK; handle_error("connect", "ENOTSOCK", -1); return -1; } /* Check family */ if (connaddr->sin_family < 0 || connaddr->sin_family >= NPROTO){ errno = EAFNOSUPPORT; handle_error("connect", "EAFNOSUPPORT", -1); return -1; } /* FIXME: Check that address is in user space, return EFAULT ? */ #endif /* make sure we don't touch any standard outputs */ if(__fd == STDIN_FILENO || __fd == STDOUT_FILENO || __fd == STDERR_FILENO){ if (realconnect == NULL) { handle_error("connect", "Unresolved symbol [connect]", -1); exit(-1); } return(realconnect(__fd, __addr, __len)); } if(__addr != NULL && (connaddr->sin_family == AF_LOCAL || connaddr->sin_family == PF_NETLINK || connaddr->sin_family == AF_NETLINK || connaddr->sin_family == AF_UNIX)) { int err = realconnect(__fd, __addr, __len); perror("connect():"); /* handle_error("connect", "Cannot connect to local socket", err); */ return err; } /* Assemble and send RPC */ char cmd[BUF_SZ]; memset(cmd, '\0', BUF_SZ); struct connect_st rpc_st; rpc_st.__tid = syscall(SYS_gettid); rpc_st.__fd = __fd; memcpy(&rpc_st.__addr, __addr, sizeof(struct sockaddr_storage)); memcpy(&rpc_st.__len, &__len, sizeof(socklen_t)); cmd[0] = RPC_CONNECT; memcpy(&cmd[1], &rpc_st, sizeof(struct connect_st)); return send_cmd(fdret_sock, cmd); } /*------------------------------------------------------------------------------ ------------------------------------ bind() ------------------------------------ ------------------------------------------------------------------------------*/ /* int sockfd, const struct sockaddr *addr, socklen_t addrlen bind() intercept function */ int bind(BIND_SIG) { if(realbind == NULL){ dwr(MSG_ERROR, "bind(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"bind(%d):\n", sockfd); /* print_addr(addr); */ #ifdef CHECKS /* Check that this is a valid fd */ if(fcntl(sockfd, F_GETFD) < 0) { errno = EBADF; handle_error("bind", "EBADF", -1); return -1; } /* Check that it is a socket */ int opt = -1; socklen_t opt_len; if(getsockopt(sockfd, SOL_SOCKET, SO_TYPE, (void *) &opt, &opt_len) < 0) { errno = ENOTSOCK; handle_error("bind", "ENOTSOCK", -1); return -1; } #endif /* make sure we don't touch any standard outputs */ if(sockfd == STDIN_FILENO || sockfd == STDOUT_FILENO || sockfd == STDERR_FILENO) return(realbind(sockfd, addr, addrlen)); /* If local, just use normal syscall */ struct sockaddr_in *connaddr; connaddr = (struct sockaddr_in *)addr; if(connaddr->sin_family == AF_LOCAL || connaddr->sin_family == AF_NETLINK || connaddr->sin_family == AF_UNIX) { int err = realbind(sockfd, addr, addrlen); dwr(MSG_DEBUG,"realbind, err = %d\n", err); return err; } int port = connaddr->sin_port; int ip = connaddr->sin_addr.s_addr; unsigned char d[4]; d[0] = ip & 0xFF; d[1] = (ip >> 8) & 0xFF; d[2] = (ip >> 16) & 0xFF; d[3] = (ip >> 24) & 0xFF; dwr(MSG_DEBUG, "bind(): %d.%d.%d.%d: %d\n", d[0],d[1],d[2],d[3], ntohs(port)); /* Assemble and send RPC */ char cmd[BUF_SZ]; struct bind_st rpc_st; rpc_st.sockfd = sockfd; rpc_st.__tid = syscall(SYS_gettid); memcpy(&rpc_st.addr, addr, sizeof(struct sockaddr_storage)); memcpy(&rpc_st.addrlen, &addrlen, sizeof(socklen_t)); cmd[0]=RPC_BIND; memcpy(&cmd[1], &rpc_st, sizeof(struct bind_st)); return send_cmd(fdret_sock, cmd); } /*------------------------------------------------------------------------------ ----------------------------------- accept4() ---------------------------------- ------------------------------------------------------------------------------*/ /* int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags */ int accept4(ACCEPT4_SIG) { if(realaccept4 == NULL){ dwr(MSG_ERROR, "accept4(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"accept4(%d):\n", sockfd); #ifdef CHECKS if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) { errno = EINVAL; return -1; } #endif int newfd = accept(sockfd, addr, addrlen); if(newfd > 0) { if(flags & SOCK_CLOEXEC) fcntl(newfd, F_SETFL, FD_CLOEXEC); if(flags & SOCK_NONBLOCK) fcntl(newfd, F_SETFL, O_NONBLOCK); } handle_error("accept4", "", newfd); return newfd; } /*------------------------------------------------------------------------------ ----------------------------------- accept() ----------------------------------- ------------------------------------------------------------------------------*/ /* int sockfd struct sockaddr *addr, socklen_t *addrlen accept() intercept function */ int accept(ACCEPT_SIG) { if(realaccept == NULL){ dwr(MSG_ERROR, "accept(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"accept(%d):\n", sockfd); #ifdef CHECKS /* Check that this is a valid fd */ if(fcntl(sockfd, F_GETFD) < 0) { return -1; errno = EBADF; dwr(MSG_DEBUG,"EBADF\n"); handle_error("accept", "EBADF", -1); return -1; } /* Check that it is a socket */ int opt; socklen_t opt_len; if(getsockopt(sockfd, SOL_SOCKET, SO_TYPE, (void *) &opt, &opt_len) < 0) { errno = ENOTSOCK; dwr(MSG_DEBUG,"ENOTSOCK\n"); handle_error("accept", "ENOTSOCK", -1); return -1; } /* Check that this socket supports accept() */ if(!(opt && (SOCK_STREAM | SOCK_SEQPACKET))) { errno = EOPNOTSUPP; dwr(MSG_DEBUG,"EOPNOTSUPP\n"); handle_error("accept", "EOPNOTSUPP", -1); return -1; } /* Check that we haven't hit the soft-limit file descriptors allowed */ struct rlimit rl; getrlimit(RLIMIT_NOFILE, &rl); if(sockfd >= rl.rlim_cur){ errno = EMFILE; dwr(MSG_DEBUG,"EMFILE\n"); handle_error("accept", "EMFILE", -1); return -1; } /* Check address length */ if(addrlen < 0) { errno = EINVAL; dwr(MSG_DEBUG,"EINVAL\n"); handle_error("accept", "EINVAL", -1); return -1; } #endif /* redirect calls for standard I/O descriptors to kernel */ if(sockfd == STDIN_FILENO || sockfd == STDOUT_FILENO || sockfd == STDERR_FILENO){ dwr(MSG_DEBUG,"realaccept():\n"); return(realaccept(sockfd, addr, addrlen)); } if(addr) addr->sa_family = AF_INET; /* TODO: also get address info */ char cmd[BUF_SZ]; /* The following line is required for libuv/nodejs to accept connections properly, however, this has the side effect of causing certain webservers to max out the CPU in an accept loop */ fcntl(sockfd, F_SETFL, SOCK_NONBLOCK); int new_conn_socket = get_new_fd(sockfd); if(new_conn_socket > 0) { dwr(MSG_DEBUG, "accept(): RX: fd = (%d) over (%d)\n", new_conn_socket, fdret_sock); /* Send our local-fd number back to service so it can complete its mapping table */ memset(cmd, '\0', BUF_SZ); cmd[0] = RPC_MAP; memcpy(&cmd[1], &new_conn_socket, sizeof(new_conn_socket)); dwr(MSG_DEBUG, "accept(): sending perceived fd (%d) to service.\n", new_conn_socket); send_cmd(fdret_sock, cmd); /* if(n_write < 0) { errno = ECONNABORTED; handle_error("accept", "ECONNABORTED - Error sending perceived FD to service", -1); return -1; } */ errno = ERR_OK; dwr(MSG_DEBUG,"accept()=%d\n", new_conn_socket); return new_conn_socket; /* OK */ } errno = EAGAIN; /* necessary? */ handle_error("accept", "EAGAIN - Error reading signal byte from service", -1); return -EAGAIN; } /*------------------------------------------------------------------------------ ------------------------------------- listen()---------------------------------- ------------------------------------------------------------------------------*/ /* int sockfd, int backlog */ int listen(LISTEN_SIG) { if(reallisten == NULL){ dwr(MSG_ERROR, "listen(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"listen(%d):\n", sockfd); int sock_type; socklen_t sock_type_len = sizeof(sock_type); #ifdef CHECKS /* Check that this is a valid fd */ if(fcntl(sockfd, F_GETFD) < 0) { errno = EBADF; handle_error("listen", "EBADF", -1); return -1; } /* Check that it is a socket */ if(getsockopt(sockfd, SOL_SOCKET, SO_TYPE, (void *) &sock_type, &sock_type_len) < 0) { errno = ENOTSOCK; handle_error("listen", "ENOTSOCK", -1); return -1; } /* Check that this socket supports accept() */ if(!(sock_type && (SOCK_STREAM | SOCK_SEQPACKET))) { errno = EOPNOTSUPP; handle_error("listen", "EOPNOTSUPP", -1); return -1; } #endif /* make sure we don't touch any standard outputs */ if(sockfd == STDIN_FILENO || sockfd == STDOUT_FILENO || sockfd == STDERR_FILENO) return(reallisten(sockfd, backlog)); if(is_mapped_to_service(sockfd) < 0) { /* We now know this socket is not one of our socketpairs */ int err = reallisten(sockfd, backlog); dwr(MSG_DEBUG,"reallisten()=%d\n", err); return err; } /* Assemble and send RPC */ char cmd[BUF_SZ]; memset(cmd, '\0', BUF_SZ); struct listen_st rpc_st; rpc_st.sockfd = sockfd; rpc_st.backlog = backlog; rpc_st.__tid = syscall(SYS_gettid); cmd[0] = RPC_LISTEN; memcpy(&cmd[1], &rpc_st, sizeof(struct listen_st)); return send_cmd(fdret_sock, cmd); } /*------------------------------------------------------------------------------ -------------------------------------- clone() --------------------------------- ------------------------------------------------------------------------------*/ /* int (*fn)(void *), void *child_stack, int flags, void *arg, ... */ int clone(CLONE_SIG) { if(realclone == NULL){ dwr(MSG_ERROR, "clone(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"clone()\n"); int err = realclone(fn, child_stack, flags, arg); checkpid(); return err; } /*------------------------------------------------------------------------------ ------------------------------------- close() ---------------------------------- ------------------------------------------------------------------------------*/ /* int fd */ int close(CLOSE_SIG) { dwr(MSG_DEBUG, "close(%d)\n", fd); if(realclose == NULL){ checkpid(); // Add for nginx support, remove for apache support. dwr(MSG_ERROR, "close(%d): SYMBOL NOT FOUND.\n", fd); return -1; } if(fd == fdret_sock) return -1; /* TODO: Ignore request to shut down our rpc fd, this is *almost always* safe */ if(fd != STDIN_FILENO && fd != STDOUT_FILENO && fd != STDERR_FILENO) return realclose(fd); return -1; } /*------------------------------------------------------------------------------ -------------------------------------- dup2() ---------------------------------- ------------------------------------------------------------------------------*/ /* int oldfd, int newfd */ int dup2(DUP2_SIG) { if(realdup2 == NULL){ dwr(MSG_ERROR, "dup2(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"dup2(%d, %d)\n", oldfd, newfd); if(oldfd == fdret_sock) { dwr(MSG_DEBUG,"client application attempted to dup2 RPC socket (%d). This is not allowed.\n", oldfd); errno = EBADF; return -1; } //if(oldfd != STDIN_FILENO && oldfd != STDOUT_FILENO && oldfd != STDERR_FILENO) // if(newfd != STDIN_FILENO && newfd != STDOUT_FILENO && newfd != STDERR_FILENO) return realdup2(oldfd, newfd); return -1; } /*------------------------------------------------------------------------------ -------------------------------------- dup3() ---------------------------------- ------------------------------------------------------------------------------*/ /* int oldfd, int newfd, int flags */ int dup3(DUP3_SIG) { if(realdup3 == NULL){ dwr(MSG_ERROR, "dup3(): SYMBOL NOT FOUND.\n"); return -1; } dwr(MSG_DEBUG,"dup3(%d, %d, %d)\n", oldfd, newfd, flags); #ifdef DEBUG /* Only do this check if we want to debug the intercept, otherwise, dont mess with the client application's logging methods */ if(newfd == STDIN_FILENO || newfd == STDOUT_FILENO || newfd == STDERR_FILENO) return newfd; /* FIXME: This is to prevent httpd from dup'ing over our stderr and preventing us from debugging */ else #endif return realdup3(oldfd, newfd, flags); } /*------------------------------------------------------------------------------ -------------------------------- getsockname() --------------------------------- ------------------------------------------------------------------------------*/ /* define GETSOCKNAME_SIG int sockfd, struct sockaddr *addr, socklen_t *addrlen */ int getsockname(GETSOCKNAME_SIG) { if (realgetsockname == NULL) { dwr(MSG_ERROR, "getsockname(): SYMBOL NOT FOUND. \n"); return -1; } dwr(MSG_DEBUG, "getsockname(%d)\n", sockfd); if(!is_mapped_to_service(sockfd)) return realgetsockname(sockfd, addr, addrlen); /* This is kind of a hack as it stands -- assumes sockaddr is sockaddr_in * and is an IPv4 address. */ /* assemble and send command */ char cmd[BUF_SZ]; struct getsockname_st rpc_st; rpc_st.sockfd = sockfd; memcpy(&rpc_st.addr, addr, *addrlen); memcpy(&rpc_st.addrlen, &addrlen, sizeof(socklen_t)); cmd[0] = RPC_GETSOCKNAME; memcpy(&cmd[1], &rpc_st, sizeof(struct getsockname_st)); send_cmd(fdret_sock, cmd); /* read address info from service */ char addrbuf[sizeof(struct sockaddr_storage)]; memset(&addrbuf, 0, sizeof(struct sockaddr_storage)); read(fdret_sock, &addrbuf, sizeof(struct sockaddr_storage)); struct sockaddr_storage sock_storage; memcpy(&sock_storage, addrbuf, sizeof(struct sockaddr_storage)); *addrlen = sizeof(struct sockaddr_in); memcpy(addr, &sock_storage, (*addrlen > sizeof(sock_storage)) ? sizeof(sock_storage) : *addrlen); addr->sa_family = AF_INET; return 0; } /*------------------------------------------------------------------------------ ------------------------------------ syscall() --------------------------------- ------------------------------------------------------------------------------*/ long syscall(SYSCALL_SIG){ if(realsyscall == NULL){ dwr(MSG_ERROR, "syscall(): SYMBOL NOT FOUND.\n"); return -1; } //dwr(MSG_DEBUG_EXTRA,"syscall(%u, ...):\n", number); va_list ap; uintptr_t a,b,c,d,e,f; va_start(ap, number); a=va_arg(ap, uintptr_t); b=va_arg(ap, uintptr_t); c=va_arg(ap, uintptr_t); d=va_arg(ap, uintptr_t); e=va_arg(ap, uintptr_t); f=va_arg(ap, uintptr_t); va_end(ap); #if defined(__i386__) /* TODO: Implement for 32-bit systems: syscall(__NR_socketcall, 18, args); args[0] = (unsigned long) fd; args[1] = (unsigned long) addr; args[2] = (unsigned long) addrlen; args[3] = (unsigned long) flags; */ #else if(number == __NR_accept4) { int sockfd = a; struct sockaddr * addr = (struct sockaddr*)b; socklen_t * addrlen = (socklen_t*)c; int flags = d; int old_errno = errno; int err = accept4(sockfd, addr, addrlen, flags); errno = old_errno; if(err == -EBADF) err = -EAGAIN; return err; } #endif return realsyscall(number,a,b,c,d,e,f); }