X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=b83ab8c61d34c3a52f8e0f35dfa63d05c3584f21;hp=2a3fc72be0ad446fa101dcbd9459107fb49f50dd;hb=e9e826f4fb415c4225ff5934fe42572ffa3b5ebc;hpb=7565af270650435630bf212592286a8c6555d749 diff --git a/net.c b/net.c index 2a3fc72b..b83ab8c6 100644 --- a/net.c +++ b/net.c @@ -6,6 +6,12 @@ /** \file net.c Networking-related helper functions. */ +/* + * Since glibc 2.8, the _GNU_SOURCE feature test macro must be defined in order + * to obtain the definition of the ucred structure. + */ +#define _GNU_SOURCE + #include /* At least NetBSD needs these. */ @@ -21,71 +27,56 @@ #include #include +#include #include "para.h" #include "error.h" +#include "crypt.h" #include "net.h" #include "string.h" #include "fd.h" - -/** 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 (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_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. + * Parse and validate IPv4 address/netmask string. * - * \param fd The file descriptor. + * \param cidr Address in CIDR notation + * \param addr Copy of the IPv4 address part of \a cidr + * \param addrlen Size of \a addr in bytes + * \param netmask Value of the netmask part in \a cidr or the + * default of 32 if not specified. * - * This must be called if and only if \p fd was activated via enable_crypt(). + * \return Pointer to \a addr if succesful, NULL on error. + * \sa RFC 4632 */ -void disable_crypt(int fd) +char *parse_cidr(const char *cidr, + char *addr, ssize_t addrlen, + int32_t *netmask) { - 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; + const char *o = cidr; + char *c = addr, *end = c + (addrlen - 1); + + *netmask = 0x20; + + if (cidr == NULL || addrlen < 1) + goto failed; + + for (o = cidr; (*c = *o == '/'? '\0' : *o); c++, o++) + if (c == end) + goto failed; + + if (*o == '/') + if (para_atoi32(++o, netmask) < 0 || + *netmask < 0 || *netmask > 0x20) + goto failed; + + if (is_valid_ipv4_address(addr)) + return addr; +failed: + *addr = '\0'; + return NULL; } + /** * Match string as a candidate IPv4 address. * @@ -97,7 +88,8 @@ static bool is_v4_dot_quad(const char *address) bool result; regex_t r; - assert(!regcomp(&r, "^([0-9]+\\.){3}[0-9]+$", REG_EXTENDED|REG_NOSUB)); + assert(para_regcomp(&r, "^([0-9]+\\.){3}[0-9]+$", + REG_EXTENDED | REG_NOSUB) >= 0); result = regexec(&r, address, 0, NULL, 0) == 0; regfree(&r); return result; @@ -195,6 +187,31 @@ failed: return NULL; } +/** + * Stringify port number, resolve into service name where defined. + * \param port 2-byte port number, in host-byte-order. + * \param transport Transport protocol name (e.g. "udp", "tcp"), or NULL. + * \return Pointer to static result buffer. + * + * \sa getservent(3), services(5), nsswitch.conf(5) + */ +const char *stringify_port(int port, const char *transport) +{ + static char service[NI_MAXSERV]; + + if (port < 0 || port > 0xFFFF) { + snprintf(service, sizeof(service), "undefined (%d)", port); + } else { + struct servent *se = getservbyport(htons(port), transport); + + if (se == NULL) + snprintf(service, sizeof(service), "%u", port); + else + snprintf(service, sizeof(service), "%s", se->s_name); + } + return service; +} + /** * Determine the socket type for a given layer-4 protocol. * @@ -376,28 +393,70 @@ int para_listen(unsigned l3type, unsigned l4type, unsigned short port) return fd; } +/** + * Determine IPv4/v6 socket address length. + * \param sa Container of IPv4 or IPv6 address. + * \return Address-family dependent address length. + */ +static socklen_t salen(const struct sockaddr *sa) +{ + assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6); + + return sa->sa_family == AF_INET6 + ? sizeof(struct sockaddr_in6) + : sizeof(struct sockaddr_in); +} + +/** + * Process IPv4/v6 address, turn v6-mapped-v4 address into normal IPv4 address. + * \param ss Container of IPv4/6 address. + * \return Pointer to normalized address (may be static storage). + * + * \sa RFC 3493 + */ +static const struct sockaddr * +normalize_ip_address(const struct sockaddr_storage *ss) +{ + const struct sockaddr_in6 *ia6 = (const struct sockaddr_in6 *)ss; + + assert(ss->ss_family == AF_INET || ss->ss_family == AF_INET6); + + if (ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&ia6->sin6_addr)) { + static struct sockaddr_in ia; + + ia.sin_family = AF_INET; + ia.sin_port = ia6->sin6_port; + memcpy(&ia.sin_addr.s_addr, &(ia6->sin6_addr.s6_addr[12]), 4); + return (const struct sockaddr *)&ia; + } + return (const struct sockaddr *)ss; +} + /** * Print numeric host and port number (beware - uses static char). * * \param sa The IPv4/IPv6 socket address to use. - * \param len The length of \p sa. * - * \sa getnameinfo(3). + * \sa getnameinfo(3), services(5), nsswitch.conf(5) */ -static char *host_and_port(struct sockaddr *sa, socklen_t len) +static char *host_and_port(const struct sockaddr_storage *ss) { - static char output[NI_MAXHOST + NI_MAXSERV + 2]; + const struct sockaddr *sa = normalize_ip_address(ss); char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV]; + static char output[sizeof(hbuf) + sizeof(sbuf) + 2]; int ret; - ret = getnameinfo(sa, len, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), - NI_NUMERICHOST | NI_NUMERICSERV); - if (ret) { + ret = getnameinfo(sa, salen(sa), + hbuf, sizeof(hbuf), + sbuf, sizeof(sbuf), + NI_NUMERICHOST); + if (ret == 0) { + snprintf(output, sizeof(output), "%s#%s", hbuf, sbuf); + } else { + snprintf(output, sizeof(output), "(unknown)"); PARA_WARNING_LOG("hostname lookup error (%s).\n", - gai_strerror(ret)); - sprintf(output, "(unknown)"); - } else - sprintf(output, "%s#%s", hbuf, sbuf); + gai_strerror(ret)); + } return output; } @@ -425,14 +484,34 @@ static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*, fd, strerror(errno)); return dont_know; } - return host_and_port((struct sockaddr *)&ss, sslen); + return host_and_port(&ss); } +/** + * Look up the local side of a connected socket structure. + * + * \param sockfd The file descriptor of the socket. + * + * \return A pointer to a static buffer containing hostname an port. This + * buffer must not be freed by the caller. + * + * \sa remote_name(). + */ char *local_name(int sockfd) { return __get_sock_name(sockfd, getsockname); } +/** + * Look up the remote side of a connected socket structure. + * + * \param sockfd The file descriptor of the socket. + * + * \return Analogous to the return value of \ref local_name() but for the + * remote side. + * + * \sa local_name(). + */ char *remote_name(int sockfd) { return __get_sock_name(sockfd, getpeername); @@ -448,54 +527,34 @@ char *remote_name(int sockfd) struct in_addr extract_v4_addr(const struct sockaddr_storage *ss) { struct in_addr ia = {.s_addr = 0}; + const struct sockaddr *sa = normalize_ip_address(ss); - if (ss->ss_family == AF_INET) - ia.s_addr = ((struct sockaddr_in *)ss)->sin_addr.s_addr; - if (ss->ss_family == AF_INET6) { - const struct in6_addr v6_addr = ((struct sockaddr_in6 *)ss)->sin6_addr; - - if (IN6_IS_ADDR_V4MAPPED(&v6_addr)) - memcpy(&ia.s_addr, &(v6_addr.s6_addr[12]), 4); - } + if (sa->sa_family == AF_INET) + ia = ((struct sockaddr_in *)sa)->sin_addr; return ia; } /** - * Encrypt and send a binary buffer. + * Send a binary buffer. * * \param fd The file descriptor. - * \param buf The buffer to be encrypted and sent. + * \param buf The buffer to be sent. * \param len The length of \a buf. * - * 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. + * Send out the buffer and try to resend the remaining part in case of short + * writes. * * \return Standard. */ int send_bin_buffer(int fd, const char *buf, size_t len) { - int ret; - crypt_function *cf = NULL; - if (!len) PARA_CRIT_LOG("len == 0\n"); - if (fd + 1 <= cda_size) - cf = crypt_data_array[fd].send; - if (cf) { - 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 = write_all(fd, (char *)outbuf, &len); - free(outbuf); - } else - ret = write_all(fd, buf, &len); - return ret; + return write_all(fd, buf, &len); } /** - * Encrypt and send null terminated buffer. + * Send a \p NULL-terminated buffer. * * \param fd The file descriptor. * \param buf The null-terminated buffer to be send. @@ -509,9 +568,8 @@ int send_buffer(int fd, const char *buf) return send_bin_buffer(fd, buf, strlen(buf)); } - /** - * Send and encrypt a buffer given by a format string. + * Send a buffer given by a format string. * * \param fd The file descriptor. * \param fmt A format string. @@ -530,51 +588,37 @@ __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...) } /** - * Receive and decrypt. + * Receive data from a file descriptor. * * \param fd The file descriptor. - * \param buf The buffer to write the decrypted data to. + * \param buf The buffer to write the data to. * \param size The size of \a buf. * - * Receive at most \a size bytes from file descriptor \a fd. If encryption is - * available, decrypt the received buffer. + * Receive at most \a size bytes from file descriptor \a fd. * - * \return The number of bytes received on success, negative on errors. + * \return The number of bytes received on success, negative on errors, zero if + * the peer has performed an orderly shutdown. * - * \sa recv(2) + * \sa recv(2). */ __must_check int recv_bin_buffer(int fd, char *buf, size_t size) { ssize_t n; - crypt_function *cf = NULL; - - 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) { - size_t numbytes = n; - unsigned char *b = (unsigned char *)buf; - (*cf)(numbytes, tmp, b, private); - } - free(tmp); - } else - n = recv(fd, buf, size, 0); + + n = recv(fd, buf, size, 0); if (n == -1) return -ERRNO_TO_PARA_ERROR(errno); return n; } /** - * Receive, decrypt and write terminating NULL byte. + * Receive and write terminating NULL byte. * * \param fd The file descriptor. - * \param buf The buffer to write the decrypted data to. + * \param buf The buffer to write the data to. * \param size The size of \a buf. * - * Read and decrypt at most \a size - 1 bytes from file descriptor \a fd and + * Read at most \a 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(). @@ -617,6 +661,33 @@ int para_accept(int fd, void *addr, socklen_t size) return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd; } +/** + * Probe the list of DCCP CCIDs supported locally by the host. + * \param ccids Array to be filled in. + * \param nccids Length of \a ccids. + * \return Pointer to \a ccids, NULL on failure. + * + * NB: This feature is only available on Linux > 2.6.30; on older kernels + * ENOPROTOOPT ("Protocol not available") will be returned. + */ +const uint8_t *dccp_available_ccids(uint8_t *ccids, uint8_t *nccids) +{ + int fd = makesock(AF_UNSPEC, IPPROTO_DCCP, 0, NULL, 0); + + if (fd < 0) + return NULL; + + if (getsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_AVAILABLE_CCIDS, + ccids, (socklen_t *)nccids) < 0) { + PARA_ERROR_LOG("No DCCP_SOCKOPT_AVAILABLE_CCIDS: %s\n", + strerror(errno)); + *nccids = 0; + } + close(fd); + + return *nccids ? ccids : NULL; +} + /** * Prepare a structure for \p AF_UNIX socket addresses. * @@ -736,7 +807,7 @@ int recv_cred_buffer(int fd, char *buf, size_t size) */ ssize_t send_cred_buffer(int sock, char *buf) { - char control[sizeof(struct cmsghdr) + 10]; + char control[sizeof(struct cmsghdr) + sizeof(struct ucred)]; struct msghdr msg; struct cmsghdr *cmsg; static struct iovec iov; @@ -856,10 +927,11 @@ int recv_pattern(int fd, const char *pattern, size_t bufsize) ret = 1; out: if (ret < 0) { - PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n, - pattern); + PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern); if (n > 0) - PARA_NOTICE_LOG("recvd: %s\n", buf); + PARA_NOTICE_LOG("recvd %d bytes: %s\n", n, buf); + else if (n < 0) + PARA_NOTICE_LOG("%s\n", para_strerror(-n)); } free(buf); return ret;