X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=ab6a98940b1e920eee7ee5e3f8f6b9bb33cf94b9;hp=10fc121912b8d242b7ca15a8081c2e7e490e44c5;hb=0b36e0a77fc750af85e969efda7bda0931f389d0;hpb=3c6cd36c4ecfb4a6fb3fba6f04ee761c534fceac diff --git a/net.c b/net.c index 10fc1219..ab6a9894 100644 --- a/net.c +++ b/net.c @@ -1,11 +1,17 @@ /* - * Copyright (C) 2005-2008 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. */ +/* + * 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. */ @@ -19,11 +25,14 @@ #define AI_ADDRCONFIG 0 #endif +#include +#include #include "para.h" #include "error.h" #include "net.h" #include "string.h" +#include "fd.h" /** Information about one encrypted connection. */ @@ -83,6 +92,155 @@ void disable_crypt(int fd) crypt_data_array[fd].private_data = NULL; } +/** + * 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; + + 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. + * + * \param address The string to match. + * \return True if \a address has "dot-quad" format. + */ +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)); + result = regexec(&r, address, 0, NULL, 0) == 0; + regfree(&r); + return result; +} + +/** + * Perform basic syntax checking on the host-part of an URL: + * + * - 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. + * + * \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 + */ +static bool host_string_ok(const char *host) +{ + 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; +} /** * Determine the socket type for a given layer-4 protocol. @@ -155,9 +313,13 @@ int makesock(unsigned l3type, unsigned l4type, int passive, /* Set up address hint structure */ memset(&hints, 0, sizeof(hints)); hints.ai_family = l3type; - /* getaddrinfo does not really work well with SOCK_DCCP */ - if (socktype == SOCK_DGRAM || socktype == SOCK_STREAM) - hints.ai_socktype = socktype; + 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; @@ -172,7 +334,7 @@ int makesock(unsigned l3type, unsigned l4type, int passive, 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? : (passive? "[loopback]" : "[localhost]"), + host? host : (passive? "[loopback]" : "[localhost]"), port, gai_strerror(rc)); return -E_ADDRESS_LOOKUP; } @@ -226,7 +388,7 @@ get_next_src: if (src == NULL && dst == NULL) { PARA_ERROR_LOG("can not create %s socket %s#%s.\n", - layer4_name(l4type), host? : (passive? + layer4_name(l4type), host? host : (passive? "[loopback]" : "[localhost]"), port); return -ERRNO_TO_PARA_ERROR(errno); } @@ -313,11 +475,31 @@ static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*, return host_and_port((struct sockaddr *)&ss, sslen); } +/** + * 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); @@ -335,7 +517,7 @@ struct in_addr extract_v4_addr(const struct sockaddr_storage *ss) struct in_addr ia = {.s_addr = 0}; if (ss->ss_family == AF_INET) - ia.s_addr = ((struct sockaddr_in *)ss)->sin_addr.s_addr; + 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; @@ -345,31 +527,6 @@ struct in_addr extract_v4_addr(const struct sockaddr_storage *ss) return ia; } -/* - * 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) -{ - 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; - } - return 1; -} - /** * Encrypt and send a binary buffer. * @@ -378,8 +535,8 @@ static int sendall(int fd, const char *buf, size_t *len) * \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. + * out the buffer, encrypted or not, and try to resend the remaining part in + * case of short writes. * * \return Standard. */ @@ -389,7 +546,7 @@ int send_bin_buffer(int fd, const char *buf, size_t len) crypt_function *cf = NULL; if (!len) - PARA_CRIT_LOG("%s", "len == 0\n"); + PARA_CRIT_LOG("len == 0\n"); if (fd + 1 <= cda_size) cf = crypt_data_array[fd].send; if (cf) { @@ -397,10 +554,10 @@ int send_bin_buffer(int fd, const char *buf, size_t len) /* 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); + ret = write_all(fd, (char *)outbuf, &len); free(outbuf); } else - ret = sendall(fd, buf, &len); + ret = write_all(fd, buf, &len); return ret; } @@ -646,7 +803,7 @@ 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; @@ -747,10 +904,9 @@ int recv_cred_buffer(int fd, char *buf, size_t size) * * \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). */ @@ -758,7 +914,7 @@ 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;