X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=net.c;h=88b3e3cc8aee0b2fadfd7783c763b062b8ac0d24;hp=543485e75c084a19ded62eff4f0393c29a157955;hb=74361f472d6d1a75a313cb3a6b4528cfeacfff0a;hpb=12d15401324e33962f1802e2d6844fdfd6d62bb9 diff --git a/net.c b/net.c index 543485e7..88b3e3cc 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 +92,114 @@ void disable_crypt(int fd) crypt_data_array[fd].private_data = 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 +272,13 @@ 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; @@ -345,31 +466,6 @@ 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 = write(fd, buf + *len, total - *len); - if (ret == -1) - return -ERRNO_TO_PARA_ERROR(errno); - *len += ret; - } - return 1; -} - /** * Encrypt and send a binary buffer. * @@ -389,7 +485,7 @@ 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 +493,10 @@ 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; } @@ -747,10 +843,9 @@ 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 +853,7 @@ 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;