X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=58221fa6754a950ba52bbb272df9438b63a0824c;hp=cb504f3cce860f26eb8dd53d6c3c0a1d33424f24;hb=e9e826f4fb415c4225ff5934fe42572ffa3b5ebc;hpb=007d547044e1d93ca56fd8a61506578e26ccdcb0 diff --git a/net.c b/net.c index cb504f3c..b83ab8c6 100644 --- a/net.c +++ b/net.c @@ -1,186 +1,580 @@ /* - * Copyright (C) 2005-2007 Andre Noll + * Copyright (C) 2005-2009 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file net.c networking-related helper functions */ +/** \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. */ +#ifndef AI_V4MAPPED +#define AI_V4MAPPED 0 +#endif +#ifndef AI_ALL +#define AI_ALL 0 +#endif +#ifndef AI_ADDRCONFIG +#define AI_ADDRCONFIG 0 +#endif + +#include +#include +#include #include "para.h" +#include "error.h" +#include "crypt.h" #include "net.h" #include "string.h" -#include "error.h" +#include "fd.h" + +/** + * Parse and validate IPv4 address/netmask string. + * + * \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. + * + * \return Pointer to \a addr if succesful, NULL on error. + * \sa RFC 4632 + */ +char *parse_cidr(const char *cidr, + char *addr, ssize_t addrlen, + int32_t *netmask) +{ + const char *o = cidr; + char *c = addr, *end = c + (addrlen - 1); + + *netmask = 0x20; + if (cidr == NULL || addrlen < 1) + goto failed; -/** holds 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, passed to \a recv() and \a send() */ - void *private_data; -}; -/** array holding per fd crypt data per */ -static struct crypt_data *crypt_data_array; -/** current size of the crypt data array */ -static unsigned cda_size = 0; + 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; +} /** - * activate encryption for one file descriptor + * Match string as a candidate IPv4 address. * - * \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 + * \param address The string to match. + * \return True if \a address has "dot-quad" format. */ -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); +static bool is_v4_dot_quad(const char *address) +{ + bool result; + regex_t r; + + 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; } /** - * deactivate encryption for a given fd + * Perform basic syntax checking on the host-part of an URL: * - * \param fd the file descriptor + * - Since ':' is invalid in IPv4 addresses and DNS names, the + * presence of ':' causes interpretation as IPv6 address; + * - next the first-match-wins algorithm from RFC 3986 is applied; + * - else the string is considered as DNS name, to be resolved later. * - * This must be called if and only if \p fd was activated via enable_crypt(). + * \param host The host string to check. + * \return True if \a host passes the syntax checks. + * + * \sa RFC 3986, 3.2.2; RFC 1123, 2.1; RFC 1034, 3.5 */ -void disable_crypt(int fd) +static bool host_string_ok(const char *host) { - 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; + if (host == NULL || *host == '\0') + return false; + if (strchr(host, ':') != NULL) + return is_valid_ipv6_address(host); + if (is_v4_dot_quad(host)) + return is_valid_ipv4_address(host); + return true; +} + +/** + * Parse and validate URL string. + * + * The URL syntax is loosely based on RFC 3986, supporting one of + * - "["host"]"[:port] for native IPv6 addresses and + * - host[:port] for IPv4 hostnames and DNS names. + * + * Native IPv6 addresses must be enclosed in square brackets, since + * otherwise there is an ambiguity with the port separator `:'. + * The 'port' part is always considered to be a number; if absent, + * it is set to -1, to indicate that a default port is to be used. + * + * The following are valid examples: + * - 10.10.1.1 + * - 10.10.1.2:8000 + * - localhost + * - localhost:8001 + * - [::1]:8000 + * - [badc0de::1] + * + * \param url The URL string to take apart. + * \param host To return the copied host part of \a url. + * \param hostlen The maximum length of \a host. + * \param port To return the port number (if any) of \a url. + * + * \return Pointer to \a host, or NULL if failed. + * If NULL is returned, \a host and \a portnum are undefined. If no + * port number was present in \a url, \a portnum is set to -1. + * + * \sa RFC 3986, 3.2.2/3.2.3 + */ +char *parse_url(const char *url, + char *host, ssize_t hostlen, + int32_t *port) +{ + const char *o = url; + char *c = host, *end = c + (hostlen - 1); + + *port = -1; + + if (o == NULL || hostlen < 1) + goto failed; + + if (*o == '[') { + for (++o; (*c = *o == ']' ? '\0' : *o); c++, o++) + if (c == end) + goto failed; + + if (*o++ != ']' || (*o != '\0' && *o != ':')) + goto failed; + } else { + for (; (*c = *o == ':'? '\0' : *o); c++, o++) + if (c == end) + goto failed; + } + + if (*o == ':') + if (para_atoi32(++o, port) < 0 || + *port < 0 || *port > 0xffff) + goto failed; + + if (host_string_ok(host)) + return host; +failed: + *host = '\0'; + 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; +} /** - * initialize a struct sockaddr_in + * Determine the socket type for a given layer-4 protocol. * - * \param addr A pointer to the struct to be initialized - * \param port The port number to use - * \param he The address to use + * \param l4type The symbolic name of the transport-layer protocol. * - * 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. + * \sa ip(7), socket(2) */ -void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he) -{ - /* host byte order */ - addr->sin_family = AF_INET; - /* short, network byte order */ - addr->sin_port = htons(port); - if (he) - addr->sin_addr = *((struct in_addr *)he->h_addr); - else - addr->sin_addr.s_addr = INADDR_ANY; - /* zero the rest of the struct */ - memset(&addr->sin_zero, '\0', 8); +static inline int sock_type(const unsigned l4type) +{ + switch (l4type) { + case IPPROTO_UDP: return SOCK_DGRAM; + case IPPROTO_TCP: return SOCK_STREAM; + case IPPROTO_DCCP: return SOCK_DCCP; + } + return -1; /* not supported here */ } -/* - * send out a buffer, resend on short writes +/** + * Pretty-print transport-layer name. + */ +static const char *layer4_name(const unsigned l4type) +{ + switch (l4type) { + case IPPROTO_UDP: return "UDP"; + case IPPROTO_TCP: return "TCP"; + case IPPROTO_DCCP: return "DCCP"; + } + return "UNKNOWN PROTOCOL"; +} + +/** + * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket. + * + * \param l3type The layer-3 type (\p AF_INET, \p AF_INET6, \p AF_UNSPEC). + * \param l4type The layer-4 type (\p IPPROTO_xxx). + * \param passive Whether this is a passive (1) or active (0) socket. + * \param host Remote or local hostname or IPv/6 address string. + * \param port_number Decimal port number. + * + * This creates a ready-made IPv4/v6 socket structure after looking up the + * necessary parameters. The interpretation of \a host depends on the value of + * \a passive: + * - on a passive socket host is interpreted as an interface IPv4/6 address + * (can be left NULL); + * - on an active socket, \a host is the peer DNS name or IPv4/6 address + * to connect to; + * - \a port_number is in either case the numeric port number (not service + * string). + * + * Furthermore, bind(2) is called on passive sockets, and connect(2) on active + * sockets. The algorithm tries all possible address combinations until it + * succeeds. + * + * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no + * matching connection could be set up (with details in the error log). + * + * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2). + */ +int makesock(unsigned l3type, unsigned l4type, int passive, + const char *host, unsigned short port_number) +{ + struct addrinfo *local = NULL, *src, + *remote = NULL, *dst, hints; + int rc, on = 1, sockfd = -1, + socktype = sock_type(l4type); + char port[6]; /* port number has at most 5 digits */ + + sprintf(port, "%u", port_number); + /* Set up address hint structure */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = l3type; + hints.ai_socktype = socktype; + /* + * getaddrinfo does not support SOCK_DCCP, so for the sake of lookup + * (and only then) pretend to be UDP. + */ + if (l4type == IPPROTO_DCCP) + hints.ai_socktype = SOCK_DGRAM; + + /* only use addresses available on the host */ + hints.ai_flags = AI_ADDRCONFIG; + if (l3type == AF_INET6) + /* use v4-mapped-v6 if no v6 addresses found */ + hints.ai_flags |= AI_V4MAPPED | AI_ALL; + + if (passive && host == NULL) + hints.ai_flags |= AI_PASSIVE; + + /* Obtain local/remote address information */ + if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) { + PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n", + layer4_name(l4type), + host? host : (passive? "[loopback]" : "[localhost]"), + port, gai_strerror(rc)); + return -E_ADDRESS_LOOKUP; + } + + /* Iterate over all src/dst combination, exhausting dst first */ + for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) { + if (src && dst && src->ai_family == AF_INET + && dst->ai_family == AF_INET6) + goto get_next_dst; /* v4 -> v6 is not possible */ + + sockfd = socket(src ? src->ai_family : dst->ai_family, + socktype, l4type); + if (sockfd < 0) + goto get_next_dst; + + /* + * Set those options that need to be set before establishing + * the connection. Reuse the address on passive (listening) + * sockets to avoid failure on restart. + */ + if (passive && setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, + &on, sizeof(on)) == -1) { + PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n", + strerror(errno)); + return -ERRNO_TO_PARA_ERROR(errno); + } + + if (src) { + if (bind(sockfd, src->ai_addr, src->ai_addrlen) < 0) { + close(sockfd); + goto get_next_src; + } + if (!dst) /* bind-only completed successfully */ + break; + } + + if (dst && connect(sockfd, dst->ai_addr, dst->ai_addrlen) == 0) + break; /* connection completed successfully */ + close(sockfd); +get_next_dst: + if (dst && (dst = dst->ai_next)) + continue; +get_next_src: + if (src && (src = src->ai_next)) /* restart inner loop */ + dst = remote; + } + if (local) + freeaddrinfo(local); + if (remote) + freeaddrinfo(remote); + + if (src == NULL && dst == NULL) { + PARA_ERROR_LOG("can not create %s socket %s#%s.\n", + layer4_name(l4type), host? host : (passive? + "[loopback]" : "[localhost]"), port); + return -ERRNO_TO_PARA_ERROR(errno); + } + return sockfd; +} + +/** + * Create a passive / listening socket. * - * \param fd the file descriptor - * \param buf The buffer to be sent - * \param len The length of \a buf + * \param l3type The network-layer type (\p AF_xxx). + * \param l4type The transport-layer type (\p IPPROTO_xxx). + * \param port The decimal port number to listen on. * - * 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). + * \return Positive integer (socket descriptor) on success, negative value + * otherwise. * - * \return This function returns 1 on success and \a -E_SEND on errors. The - * number of bytes actually sent is stored upon successful return in \a len. + * \sa makesock(), ip(7), ipv6(7), bind(2), listen(2). */ -static int sendall(int fd, const char *buf, size_t *len) -{ - size_t total = 0, 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); +int para_listen(unsigned l3type, unsigned l4type, unsigned short port) +{ + int ret, fd = makesock(l3type, l4type, 1, NULL, port); + + if (fd > 0) { + ret = listen(fd, BACKLOG); + if (ret < 0) { + close(fd); + return -ERRNO_TO_PARA_ERROR(errno); + } + PARA_INFO_LOG("listening on %s port %u, fd %d\n", + layer4_name(l4type), port, fd); } - *len = total; /* return number actually sent here */ - return n == -1? -E_SEND : 1; /* return 1 on success */ + return fd; } /** - * encrypt and send buffer + * 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). * - * \param fd: the file descriptor - * \param buf the buffer to be encrypted and sent - * \param len the length of \a buf + * \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). * - * Check if encrytpion 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. + * \param sa The IPv4/IPv6 socket address to use. * - * \return Positive on success, \p -E_SEND on errors. + * \sa getnameinfo(3), services(5), nsswitch.conf(5) */ -int send_bin_buffer(int fd, const char *buf, size_t len) +static char *host_and_port(const struct sockaddr_storage *ss) { + 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; - crypt_function *cf = NULL; + 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)); + } + return output; +} + +/** + * Look up the local or remote side of a connected socket structure. + * + * \param fd The socket descriptor of the connected socket. + * \param getname Either \p getsockname() for local, or \p getpeername() for + * remote side. + * + * \return A static character string identifying hostname and port of the + * chosen side. + * + * \sa getsockname(2), getpeername(2). + */ +static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*, + socklen_t *)) +{ + struct sockaddr_storage ss; + socklen_t sslen = sizeof(ss); + + if (getname(fd, (struct sockaddr *)&ss, &sslen) < 0) { + static char *dont_know = "(don't know)"; + PARA_ERROR_LOG("can not determine address from fd %d: %s\n", + fd, strerror(errno)); + return dont_know; + } + 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); +} + +/** + * Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage. + * \param ss Container of IPv4/6 address + * \return Extracted IPv4 address (different from 0) or 0 if unsuccessful. + * + * \sa RFC 3493 + */ +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 (sa->sa_family == AF_INET) + ia = ((struct sockaddr_in *)sa)->sin_addr; + return ia; +} + +/** + * Send a binary buffer. + * + * \param fd The file descriptor. + * \param buf The buffer to be sent. + * \param len The length of \a buf. + * + * 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) +{ if (!len) - PARA_CRIT_LOG("%s", "len == 0\n"); - if (fd + 1 <= cda_size) - cf = crypt_data_array[fd].send; - if (cf) { - void *private = crypt_data_array[fd].private_data; - unsigned char *outbuf = para_malloc(len); - (*cf)(len, (unsigned char *)buf, outbuf, private); - ret = sendall(fd, (char *)outbuf, &len); - free(outbuf); - } else - ret = sendall(fd, buf, &len); - return ret; + PARA_CRIT_LOG("len == 0\n"); + 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 + * \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) { 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 + * \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, ...) { @@ -194,56 +588,40 @@ __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 size the size of \a buf + * \param fd The file descriptor. + * \param buf The buffer to write the data to. + * \param size The size of \a buf. * - * Receive at most \a size bytes from filedescriptor 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. 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, 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) - n = -E_RECV; + 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 size the size of \a buf + * \param fd The file descriptor. + * \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(). + * \return The return value of the underlying call to \a recv_bin_buffer(). * * \sa recv_bin_buffer() */ @@ -251,8 +629,7 @@ int recv_buffer(int fd, char *buf, size_t size) { int n; - if (!size) - return -E_RECV; + assert(size); n = recv_bin_buffer(fd, buf, size - 1); if (n >= 0) buf[n] = '\0'; @@ -262,73 +639,15 @@ int recv_buffer(int fd, char *buf, size_t size) } /** - * wrapper around gethostbyname - * - * \param host hostname or IPv4 address - * \param ret the hostent structure is returned here - * - * \return positive on success, negative on errors. On success, \a ret - * contains the return value of the underlying gethostbyname() call. - * - * \sa gethostbyname(2) - */ -int get_host_info(char *host, struct hostent **ret) -{ - PARA_INFO_LOG("getting host info of %s\n", host); - /* FIXME: gethostbyname() is obsolete */ - *ret = gethostbyname(host); - return *ret? 1 : -E_HOST_INFO; -} - -/** - * a wrapper around socket(2) - * - * 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) - */ -int get_socket(void) -{ - int socket_fd; - - if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) - return -E_SOCKET; - return socket_fd; -} - -/** - * a wrapper around connect(2) - * - * \param fd the file descriptor - * \param their_addr the address to connect + * Wrapper around the accept system call. * - * \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 - * - * \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 + * \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. * * Accept incoming connections on \a addr. Retry if interrupted. * - * \return The new file descriptor on success, \a -E_ACCEPT on errors. + * \return The new file descriptor on success, negative on errors. * * \sa accept(2). */ @@ -339,31 +658,48 @@ int para_accept(int fd, void *addr, socklen_t size) do new_fd = accept(fd, (struct sockaddr *) addr, &size); while (new_fd < 0 && errno == EINTR); - return new_fd < 0? -E_ACCEPT : new_fd; + return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd; } -static int setserversockopts(int socket_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 yes = 1; + int fd = makesock(AF_UNSPEC, IPPROTO_DCCP, 0, NULL, 0); - if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes, - sizeof(int)) == -1) - return -E_SETSOCKOPT; - return 1; + 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 + * Prepare a structure for \p AF_UNIX socket addresses. * - * \param u pointer to the struct to be prepared - * \param name the socket pathname + * \param u Pointer to the struct to be prepared. + * \param name The socket pathname. * * This just copies \a name to the sun_path component of \a u. * * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer * than \p UNIX_PATH_MAX. */ -int init_unix_addr(struct sockaddr_un *u, const char *name) +static int init_unix_addr(struct sockaddr_un *u, const char *name) { if (strlen(name) >= UNIX_PATH_MAX) return -E_NAME_TOO_LONG; @@ -380,7 +716,7 @@ int init_unix_addr(struct sockaddr_un *u, const char *name) * \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, + * This function creates a local socket for sequenced, reliable, * two-way, connection-based byte streams. * * \return The file descriptor, on success, negative on errors. @@ -394,18 +730,58 @@ int create_local_socket(const char *name, struct sockaddr_un *unix_addr, { 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; +} + +/** + * Prepare, create, and connect to a Unix domain socket for local communication. + * + * \param name The socket pathname. + * + * This function creates a local socket for sequenced, reliable, two-way, + * connection-based byte streams. + * + * \return The file descriptor, on success, negative on errors. + * + * \sa create_local_socket(), unix(7), connect(2). + */ +int create_remote_socket(const char *name) +{ + struct sockaddr_un unix_addr; + int fd, ret; + + ret = init_unix_addr(&unix_addr, name); + if (ret < 0) + return ret; + fd = socket(PF_UNIX, SOCK_STREAM, 0); + if (fd < 0) + return -ERRNO_TO_PARA_ERROR(errno); + if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) == -1) { + ret = -ERRNO_TO_PARA_ERROR(errno); + goto err; + } + return fd; +err: + close(fd); + return ret; } #ifndef HAVE_UCRED @@ -419,20 +795,19 @@ int recv_cred_buffer(int fd, char *buf, size_t size) } #else /* HAVE_UCRED */ /** - * send NULL terminated buffer and Unix credentials of the current process + * Send \p NULL-terminated buffer and Unix credentials of the current process. * - * \param sock the socket file descriptor - * \param buf the buffer to be sent + * \param sock The socket file descriptor. + * \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) + * \sa sendmsg(2), okir's Black Hats Manual. */ 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; @@ -473,16 +848,15 @@ static void dispose_fds(int *fds, unsigned num) } /** - * receive a buffer and the Unix credentials of the sending process + * Receive a buffer and the Unix credentials of the sending process. * - * \param fd the socket file descriptor - * \param buf the buffer to store the message - * \param size the size of \a buffer + * \param fd the socket file descriptor. + * \param buf the buffer to store the message. + * \param size the size of \a buffer. * * \return negative on errors, the user id on success. * - * \sa okir's Black Hats Manual - * \sa recvmsg(2) + * \sa recvmsg(2), okir's Black Hats Manual. */ int recv_cred_buffer(int fd, char *buf, size_t size) { @@ -525,72 +899,26 @@ int recv_cred_buffer(int fd, char *buf, size_t size) } #endif /* HAVE_UCRED */ -/** how many pending connections queue will hold */ -#define BACKLOG 10 - -/** - * create a socket, bind it and listen - * - * \param port the tcp port to listen on - * - * \return The file descriptor of the created socket, negative - * on errors. - * - * \sa get_socket() - * \sa setsockopt(2) - * \sa bind(2) - * \sa listen(2) - */ -int init_tcp_socket(int port) -{ - struct sockaddr_in my_addr; - int fd, ret = get_socket(); - - if (ret < 0) - return ret; - fd = ret; - ret = setserversockopts(fd); - if (ret < 0) - 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)); - goto err; - } - ret = -E_LISTEN; - if (listen(fd, BACKLOG) == -1) - goto err; - PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd); - return fd; -err: - close(fd); - return ret; -} - /** - * receive a buffer and check for a pattern + * Receive a buffer and check for a pattern. * - * \param fd the file descriptor to receive from - * \param pattern the expected pattern - * \param bufsize the size of the internal buffer + * \param fd The file descriptor to receive from. + * \param pattern The expected pattern. + * \param bufsize The size of the internal buffer. * * \return Positive if \a pattern was received, negative otherwise. * - * This function creates a buffer of size \a bufsize and tries - * 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. + * This function tries 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) + * \sa recv_buffer(), \sa strncasecmp(3). */ int recv_pattern(int fd, const char *pattern, size_t bufsize) { size_t len = strlen(pattern); char *buf = para_malloc(bufsize + 1); - int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize); + int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize + 1); if (n < len) goto out; @@ -599,9 +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;