diff options
Diffstat (limited to 'winsup/cygwin/socket_tests/lib/inet_sockets.c')
| -rw-r--r-- | winsup/cygwin/socket_tests/lib/inet_sockets.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/winsup/cygwin/socket_tests/lib/inet_sockets.c b/winsup/cygwin/socket_tests/lib/inet_sockets.c new file mode 100644 index 000000000..396dbf906 --- /dev/null +++ b/winsup/cygwin/socket_tests/lib/inet_sockets.c @@ -0,0 +1,188 @@ +/*************************************************************************\ +* Copyright (C) Michael Kerrisk, 2018. * +* * +* This program is free software. You may use, modify, and redistribute it * +* under the terms of the GNU Lesser General Public License as published * +* by the Free Software Foundation, either version 3 or (at your option) * +* any later version. This program is distributed without any warranty. * +* See the files COPYING.lgpl-v3 and COPYING.gpl-v3 for details. * +\*************************************************************************/ + +/* Listing 59-9 */ + +/* inet_sockets.c + + A package of useful routines for Internet domain sockets. +*/ +#define _BSD_SOURCE /* To get NI_MAXHOST and NI_MAXSERV + definitions from <netdb.h> */ +#include "af_unix_hdr.h" +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <netdb.h> +#include "inet_sockets.h" /* Declares functions defined here */ + +/* The following arguments are common to several of the routines + below: + + 'host': NULL for loopback IP address, or + a host name or numeric IP address + 'service': either a name or a port number + 'type': either SOCK_STREAM or SOCK_DGRAM +*/ + +/* Create socket and connect it to the address specified by + 'host' + 'service'/'type'. Return socket descriptor on success, + or -1 on error */ + +int +inetConnect(const char *host, const char *service, int type) +{ + struct addrinfo hints; + struct addrinfo *result, *rp; + int sfd, s; + + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_canonname = NULL; + hints.ai_addr = NULL; + hints.ai_next = NULL; + hints.ai_family = AF_UNSPEC; /* Allows IPv4 or IPv6 */ + hints.ai_socktype = type; + + s = getaddrinfo(host, service, &hints, &result); + if (s != 0) { + errno = ENOSYS; + return -1; + } + + /* Walk through returned list until we find an address structure + that can be used to successfully connect a socket */ + + for (rp = result; rp != NULL; rp = rp->ai_next) { + sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); + if (sfd == -1) + continue; /* On error, try next address */ + + if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1) + break; /* Success */ + + /* Connect failed: close this socket and try next address */ + + close(sfd); + } + + freeaddrinfo(result); + + return (rp == NULL) ? -1 : sfd; +} + +/* Create an Internet domain socket and bind it to the address + { wildcard-IP-address + 'service'/'type' }. + If 'doListen' is TRUE, then make this a listening socket (by + calling listen() with 'backlog'), with the SO_REUSEADDR option set. + If 'addrLen' is not NULL, then use it to return the size of the + address structure for the address family for this socket. + Return the socket descriptor on success, or -1 on error. */ + +static int /* Public interfaces: inetBind() and inetListen() */ +inetPassiveSocket(const char *service, int type, socklen_t *addrlen, + Boolean doListen, int backlog) +{ + struct addrinfo hints; + struct addrinfo *result, *rp; + int sfd, optval, s; + + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_canonname = NULL; + hints.ai_addr = NULL; + hints.ai_next = NULL; + hints.ai_socktype = type; + hints.ai_family = AF_UNSPEC; /* Allows IPv4 or IPv6 */ + hints.ai_flags = AI_PASSIVE; /* Use wildcard IP address */ + + s = getaddrinfo(NULL, service, &hints, &result); + if (s != 0) + return -1; + + /* Walk through returned list until we find an address structure + that can be used to successfully create and bind a socket */ + + optval = 1; + for (rp = result; rp != NULL; rp = rp->ai_next) { + sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); + if (sfd == -1) + continue; /* On error, try next address */ + + if (doListen) { + if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &optval, + sizeof(optval)) == -1) { + close(sfd); + freeaddrinfo(result); + return -1; + } + } + + if (bind(sfd, rp->ai_addr, rp->ai_addrlen) == 0) + break; /* Success */ + + /* bind() failed: close this socket and try next address */ + + close(sfd); + } + + if (rp != NULL && doListen) { + if (listen(sfd, backlog) == -1) { + freeaddrinfo(result); + return -1; + } + } + + if (rp != NULL && addrlen != NULL) + *addrlen = rp->ai_addrlen; /* Return address structure size */ + + freeaddrinfo(result); + + return (rp == NULL) ? -1 : sfd; +} + +/* Create stream socket, bound to wildcard IP address + port given in + 'service'. Make the socket a listening socket, with the specified + 'backlog'. Return socket descriptor on success, or -1 on error. */ + +int +inetListen(const char *service, int backlog, socklen_t *addrlen) +{ + return inetPassiveSocket(service, SOCK_STREAM, addrlen, TRUE, backlog); +} + +/* Create socket bound to wildcard IP address + port given in + 'service'. Return socket descriptor on success, or -1 on error. */ + +int +inetBind(const char *service, int type, socklen_t *addrlen) +{ + return inetPassiveSocket(service, type, addrlen, FALSE, 0); +} + +/* Given a socket address in 'addr', whose length is specified in + 'addrlen', return a null-terminated string containing the host and + service names in the form "(hostname, port#)". The string is + returned in the buffer pointed to by 'addrStr', and this value is + also returned as the function result. The caller must specify the + size of the 'addrStr' buffer in 'addrStrLen'. */ + +char * +inetAddressStr(const struct sockaddr *addr, socklen_t addrlen, + char *addrStr, int addrStrLen) +{ + char host[NI_MAXHOST], service[NI_MAXSERV]; + + if (getnameinfo(addr, addrlen, host, NI_MAXHOST, + service, NI_MAXSERV, NI_NUMERICSERV) == 0) + snprintf(addrStr, addrStrLen, "(%s, %s)", host, service); + else + snprintf(addrStr, addrStrLen, "(?UNKNOWN?)"); + + return addrStr; +} |