X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=cffd250e182d36e94a1ffe06db9f96abcabe3100;hp=850a9f3996990bfd76a0e3586fc44e9d82c4b271;hb=025bd85e6a7c4618b4741762982b37df35eb7725;hpb=0b976cff31e330df80b7a278d5f9d3a0615a644c diff --git a/net.c b/net.c index 850a9f39..cffd250e 100644 --- a/net.c +++ b/net.c @@ -1,60 +1,88 @@ /* - * Copyright (C) 2005-2006 Andre Noll + * Copyright (C) 2005-2007 Andre Noll * - * 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 2 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, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file net.c networking-related helper functions */ +/** \file net.c Networking-related helper functions. */ + +#include /* hostent */ #include "para.h" +#include "error.h" #include "net.h" #include "string.h" -#include "error.h" -static crypt_function **crypt_functions; -static unsigned max_crypt_fd; -void enable_crypt(int fd, crypt_function *recv, crypt_function *send) +/** Information about one encrypted connection. */ +struct crypt_data { + /** Function used to decrypt received data. */ + crypt_function *recv; + /** Function used to encrypt data to be sent. */ + crypt_function *send; + /** + * Context-dependent data (crypt keys), passed verbatim to the above + * crypt functions. + */ + void *private_data; +}; +/** Array holding per fd crypt data. */ +static struct crypt_data *crypt_data_array; +/** Current size of the crypt data array. */ +static unsigned cda_size = 0; + +/** + * Activate encryption for one file descriptor. + * + * \param fd The file descriptor. + * \param recv_f The function used for decrypting received data. + * \param send_f The function used for encrypting before sending. + * \param private_data User data supplied by the caller. + */ +void enable_crypt(int fd, crypt_function *recv_f, crypt_function *send_f, + void *private_data) { - if (max_crypt_fd < fd) { - crypt_functions = para_realloc(crypt_functions, - 2 * (fd + 1) * sizeof(crypt_function*)); - max_crypt_fd = fd; + if (fd + 1 > cda_size) { + crypt_data_array = para_realloc(crypt_data_array, + (fd + 1) * sizeof(struct crypt_data)); + memset(crypt_data_array + cda_size, 0, + (fd + 1 - cda_size) * sizeof(struct crypt_data)); + cda_size = fd + 1; } - crypt_functions[2 * fd] = recv; - crypt_functions[2 * fd + 1] = send; + crypt_data_array[fd].recv = recv_f; + crypt_data_array[fd].send = send_f; + crypt_data_array[fd].private_data = private_data; PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd); } +/** + * Deactivate encryption for a given fd. + * + * \param fd The file descriptor. + * + * This must be called if and only if \p fd was activated via enable_crypt(). + */ void disable_crypt(int fd) { - crypt_functions[2 * fd] = NULL; - crypt_functions[2 * fd + 1] = NULL; + if (cda_size < fd + 1) + return; + crypt_data_array[fd].recv = NULL; + crypt_data_array[fd].send = NULL; + crypt_data_array[fd].private_data = NULL; } /** - * initialize a struct sockaddr_in - * @param addr A pointer to the struct to be initialized - * @param port The port number to use - * @param he The address to use + * Initialize a struct sockaddr_in. + * + * \param addr A pointer to the struct to be initialized. + * \param port The port number to use. + * \param he The address to use. * - * If \a he is null (server mode), \a addr->sin_addr is initialized with \p INADDR_ANY. - * Otherwise, the address given by \a he is copied to addr. + * If \a he is null (server mode), \a addr->sin_addr is initialized with \p + * INADDR_ANY. Otherwise, the address given by \a he is copied to addr. */ -void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he) +static void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he) { /* host byte order */ addr->sin_family = AF_INET; @@ -69,60 +97,57 @@ void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he) } /* - * send out a buffer, resend on short writes - * @param fd the file descriptor - * @param buf The buffer to be sent - * @len The length of \a buf - * - * Due to circumstances beyond your control, the kernel might not send all the - * data out in one chunk, and now, my friend, it's up to us to get the data out - * there (Beej's Guide to Network Programming). + * Send out a buffer, resend on short writes. + * + * \param fd The file descriptor. + * \param buf The buffer to be sent. + * \param len The length of \a buf. + * + * \return Standard. In any case, the number of bytes actually sent is stored + * in \a len. */ static int sendall(int fd, const char *buf, size_t *len) { - int total = 0; /* how many bytes we've sent */ - int bytesleft = *len; /* how many we have left to send */ - int n = -1; - - while (total < *len) { - n = send(fd, buf + total, bytesleft, 0); - if (n == -1) - break; - total += n; - bytesleft -= n; - if (total < *len) - PARA_DEBUG_LOG("short write (%zd byte(s) left)", - *len - total); + size_t total = *len; + + assert(total); + *len = 0; + while (*len < total) { + int ret = send(fd, buf + *len, total - *len, 0); + if (ret == -1) + return -ERRNO_TO_PARA_ERROR(errno); + *len += ret; } - *len = total; /* return number actually sent here */ - return n == -1? -E_SEND : 1; /* return 1 on success */ + return 1; } /** - * encrypt and send buffer - * @param fd: the file descriptor - * @param buf the buffer to be encrypted and sent - * @param len the length of \a buf + * Encrypt and send a binary buffer. + * + * \param fd The file descriptor. + * \param buf The buffer to be encrypted and sent. + * \param len The length of \a buf. * - * Check if encrytion is available. If yes, encrypt the given buffer. Send out - * the buffer, encrypted or not, and try to resend the remaing part in case of - * short writes. + * Check if encryption is available. If yes, encrypt the given buffer. Send + * out the buffer, encrypted or not, and try to resend the remaing part in case + * of short writes. * - * @return Positive on success, \p -E_SEND on errors. + * \return Standard. */ int send_bin_buffer(int fd, const char *buf, size_t len) { int ret; crypt_function *cf = NULL; - if (fd <= max_crypt_fd) - cf = crypt_functions[2 * fd + 1]; - if (!len) PARA_CRIT_LOG("%s", "len == 0\n"); + if (fd + 1 <= cda_size) + cf = crypt_data_array[fd].send; if (cf) { - unsigned char *outbuf = para_malloc(len); - (*cf)(len, (unsigned char *)buf, outbuf); + void *private = crypt_data_array[fd].private_data; + /* RC4 may write more than len to the output buffer */ + unsigned char *outbuf = para_malloc(ROUND_UP(len, 8)); + (*cf)(len, (unsigned char *)buf, outbuf, private); ret = sendall(fd, (char *)outbuf, &len); free(outbuf); } else @@ -131,13 +156,14 @@ int send_bin_buffer(int fd, const char *buf, size_t len) } /** - * encrypt and send null terminated buffer. - * @param fd the file descriptor - * @param buf the null-terminated buffer to be send + * Encrypt and send null terminated buffer. + * + * \param fd The file descriptor. + * \param buf The null-terminated buffer to be send. * * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)). * - * @return Positive on success, \p -E_SEND on errors. + * \return Standard. */ int send_buffer(int fd, const char *buf) { @@ -146,11 +172,12 @@ int send_buffer(int fd, const char *buf) /** - * send and encrypt a buffer given by a format string - * @param fd the file descriptor - * @param fmt a format string + * Send and encrypt a buffer given by a format string. + * + * \param fd The file descriptor. + * \param fmt A format string. * - * @return Positive on success, \p -E_SEND on errors. + * \return Standard. */ __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...) { @@ -164,55 +191,62 @@ __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...) } /** - * receive and decrypt. + * Receive and decrypt. * - * @param fd the file descriptor - * @param buf the buffer to write the decrypted data to - * @param size the size of @param buf + * \param fd The file descriptor. + * \param buf The buffer to write the decrypted data to. + * \param size The size of \a buf. * - * Receive at most \a size bytes from filedescriptor fd. If encrytion is + * Receive at most \a size bytes from file descriptor \a fd. If encryption is * available, decrypt the received buffer. * - * @return the number of bytes received on success. On receive errors, -E_RECV - * is returned. On crypt errors, the corresponding crypt error number is - * returned. + * \return The number of bytes received on success, negative on errors. + * * \sa recv(2) */ -__must_check int recv_bin_buffer(int fd, char *buf, ssize_t size) +__must_check int recv_bin_buffer(int fd, char *buf, size_t size) { - int n; + ssize_t n; crypt_function *cf = NULL; - if (fd <= max_crypt_fd) - cf = crypt_functions[2 * fd]; + if (fd + 1 <= cda_size) + cf = crypt_data_array[fd].recv; if (cf) { unsigned char *tmp = para_malloc(size); + void *private = crypt_data_array[fd].private_data; n = recv(fd, tmp, size, 0); - if (n > 0) - (*cf)(n, tmp, (unsigned char *)buf); + if (n > 0) { + size_t numbytes = n; + unsigned char *b = (unsigned char *)buf; + (*cf)(numbytes, tmp, b, private); + } free(tmp); } else n = recv(fd, buf, size, 0); if (n == -1) - n = -E_RECV; + return -ERRNO_TO_PARA_ERROR(errno); return n; } /** - * receive, decrypt and write terminating NULL byte + * Receive, decrypt and write terminating NULL byte. + * + * \param fd The file descriptor. + * \param buf The buffer to write the decrypted data to. + * \param size The size of \a buf. * - * @param fd the file descriptor - * @param buf the buffer to write the decrypted data to - * @param size the size of \a buf + * Read and decrypt at most \a size - 1 bytes from file descriptor \a fd and + * write a NULL byte at the end of the received data. * - * Read and decrypt at most size - 1 bytes from file descriptor \a fd and write - * a NULL byte at the end of the received data. + * \return The return value of the underlying call to \a recv_bin_buffer(). * -*/ -int recv_buffer(int fd, char *buf, ssize_t size) + * \sa recv_bin_buffer() + */ +int recv_buffer(int fd, char *buf, size_t size) { int n; + assert(size); n = recv_bin_buffer(fd, buf, size - 1); if (n >= 0) buf[n] = '\0'; @@ -222,67 +256,67 @@ int recv_buffer(int fd, char *buf, ssize_t size) } /** - * wrapper around gethostbyname + * Establish a tcp connection. * - * \param host hostname or IPv4 address - * \param ret the hostent structure is returned here + * \param host Hostname or IPv4 address. + * \param port The tcp port. * - * \return positive on success, negative on errors. On success, \a ret - * contains the return value of the underlying gethostbyname() call. - * - * \sa gethostbyname(2) + * \return Negative on errors, a valid file descriptor on success. */ -int get_host_info(char *host, struct hostent **ret) +int tcp_connect(char *host, int port) { + struct sockaddr_in addr; + struct hostent *he; + int ret, fd; + PARA_INFO_LOG("getting host info of %s\n", host); /* FIXME: gethostbyname() is obsolete */ - *ret = gethostbyname(host); - return *ret? 1 : -E_HOST_INFO; + he = gethostbyname(host); + if (!he) + return -ERRNO_TO_PARA_ERROR(h_errno); + init_sockaddr(&addr, port, he); + ret = get_stream_socket(AF_INET); + if (ret < 0) + return ret; + fd = ret; + ret = PARA_CONNECT(fd, &addr); + if (ret >= 0) + return fd; + close(fd); + return ret; } /** - * a wrapper around socket(2) + * A wrapper around socket(2). + * + * \param domain The communication domain that selects the protocol family. * * Create an IPv4 socket for sequenced, reliable, two-way, connection-based * byte streams. * - * @return The socket fd on success, -E_SOCKET on errors. - * \sa socket(2) + * \return The socket fd on success, negative on errors. + * + * \sa socket(2). */ -int get_socket(void) +int get_stream_socket(int domain) { - int socket_fd; + int fd = socket(domain, SOCK_STREAM, 0); - if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) - return -E_SOCKET; - return socket_fd; + if (fd < 0) + return -ERRNO_TO_PARA_ERROR(errno); + return fd; } /** - * a wrapper around connect(2) + * Wrapper around the accept system call. * - * @param fd the file descriptor - * @param their_addr the address to connect + * \param fd The listening socket. + * \param addr Structure which is filled in with the address of the peer socket. + * \param size Should contain the size of the structure pointed to by \a addr. * - * @return \p -E_CONNECT on errors, 1 on success - * \sa connect(2) - */ -int para_connect(int fd, struct sockaddr_in *their_addr) -{ - int ret; - - if ((ret = connect(fd, (struct sockaddr *)their_addr, - sizeof(struct sockaddr))) == -1) - return -E_CONNECT; - return 1; -} - -/** - * paraslash's wrapper around the accept system call + * Accept incoming connections on \a addr. Retry if interrupted. * - * @param fd the listening socket - * @param addr structure which is filled in with the address of the peer socket - * @param size should contain the size of the structure pointed to by \a addr + * \return The new file descriptor on success, negative on errors. * * \sa accept(2). */ @@ -290,18 +324,10 @@ int para_accept(int fd, void *addr, socklen_t size) { int new_fd; - new_fd = accept(fd, (struct sockaddr *) addr, &size); - return new_fd == -1? -E_ACCEPT : new_fd; -} - -static int setserversockopts(int socket_fd) -{ - int yes = 1; - - if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes, - sizeof(int)) == -1) - return -E_SETSOCKOPT; - return 1; + do + new_fd = accept(fd, (struct sockaddr *) addr, &size); + while (new_fd < 0 && errno == EINTR); + return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd; } /** @@ -326,40 +352,48 @@ int init_unix_addr(struct sockaddr_un *u, const char *name) } /** - * prepare, create, and bind and socket for local communication + * Prepare, create, and bind a socket for local communication. * - * \param name the socket pathname - * \param unix_addr pointer to the \p AF_UNIX socket structure - * \param mode the desired mode of the socket + * \param name The socket pathname. + * \param unix_addr Pointer to the \p AF_UNIX socket structure. + * \param mode The desired mode of the socket. * * This functions creates a local socket for sequenced, reliable, * two-way, connection-based byte streams. + * + * \return The file descriptor, on success, negative on errors. + * * \sa socket(2) * \sa bind(2) * \sa chmod(2) */ -int create_pf_socket(const char *name, struct sockaddr_un *unix_addr, int mode) +int create_local_socket(const char *name, struct sockaddr_un *unix_addr, + mode_t mode) { int fd, ret; - fd = socket(PF_UNIX, SOCK_STREAM, 0); - if (fd < 0) - return -E_SOCKET; -// unlink(name); ret = init_unix_addr(unix_addr, name); if (ret < 0) return ret; - if (bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX) < 0) - return -E_BIND; + ret = socket(PF_UNIX, SOCK_STREAM, 0); + if (ret < 0) + return -ERRNO_TO_PARA_ERROR(errno); + fd = ret; + ret = bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX); + if (ret < 0) { + ret = -ERRNO_TO_PARA_ERROR(errno); + goto err; + } + ret = -E_CHMOD; if (chmod(name, mode) < 0) - return -E_CHMOD; + goto err; return fd; +err: + close(fd); + return ret; } #ifndef HAVE_UCRED - struct ucred { - uid_t uid, pid, gid; -}; ssize_t send_cred_buffer(int sock, char *buf) { return send_buffer(sock, buf); @@ -376,7 +410,8 @@ int recv_cred_buffer(int fd, char *buf, size_t size) * \param buf the buffer to be sent * * \return On success, this call returns the number of characters sent. On - * error, \p -E_SENDMSG ist returned. + * error, \p -E_SENDMSG is returned. + * * \sa okir's Black Hats Manual * \sa sendmsg(2) */ @@ -414,7 +449,7 @@ ssize_t send_cred_buffer(int sock, char *buf) return ret; } -static void dispose_fds(int *fds, int num) +static void dispose_fds(int *fds, unsigned num) { int i; @@ -479,38 +514,42 @@ int recv_cred_buffer(int fd, char *buf, size_t size) #define BACKLOG 10 /** - * create a socket, bind it and listen - * \param port the tcp port to listen on + * Create a tcp socket, bind it and listen on the given port. * - * \return The file descriptor of the created socket, negative - * on errors. + * \param port The tcp port to listen on. * - * \sa get_socket() + * \return The file descriptor of the created socket, negative on errors. + * + * \sa get_stream_socket() * \sa setsockopt(2) * \sa bind(2) * \sa listen(2) */ -int init_tcp_socket(int port) +int tcp_listen(int port) { struct sockaddr_in my_addr; - int fd, ret = get_socket(); + int fd, ret = get_stream_socket(AF_INET); if (ret < 0) return ret; fd = ret; - ret = setserversockopts(fd); - if (ret < 0) + ret = 1; + ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &ret, sizeof(int)); + if (ret < 0) { + ret = -ERRNO_TO_PARA_ERROR(errno); goto err; + } init_sockaddr(&my_addr, port, NULL); - ret = -E_BIND; - if (bind(fd, (struct sockaddr *)&my_addr, - sizeof(struct sockaddr)) == -1) { - PARA_CRIT_LOG("bind error: %s\n", strerror(errno)); + ret = bind(fd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)); + if (ret < 0) { + ret = -ERRNO_TO_PARA_ERROR(errno); goto err; } - ret = -E_LISTEN; - if (listen(fd, BACKLOG) == -1) + ret = listen(fd, BACKLOG); + if (ret < 0) { + ret = -ERRNO_TO_PARA_ERROR(errno); goto err; + } PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd); return fd; err: @@ -531,6 +570,7 @@ err: * to receive at most \a bufsize bytes from file descriptor \a fd. * If at least \p strlen(\a pattern) bytes were received, the beginning of * the received buffer is compared with \a pattern, ignoring case. + * * \sa recv_buffer() * \sa strncasecmp(3) */ @@ -546,8 +586,11 @@ int recv_pattern(int fd, const char *pattern, size_t bufsize) goto out; ret = 1; out: - if (ret < 0) - PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern); + if (ret < 0) { + PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n, pattern); + if (n > 0) + PARA_NOTICE_LOG("recvd: %s\n", buf); + } free(buf); return ret; }