diff options
Diffstat (limited to 'src/util/inet_connect.c')
| -rw-r--r-- | src/util/inet_connect.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/util/inet_connect.c b/src/util/inet_connect.c new file mode 100644 index 0000000..0f5542e --- /dev/null +++ b/src/util/inet_connect.c @@ -0,0 +1,189 @@ +/*++ +/* NAME +/* inet_connect 3 +/* SUMMARY +/* connect to TCP listener +/* SYNOPSIS +/* #include <connect.h> +/* +/* int inet_windowsize; +/* +/* int inet_connect(addr, block_mode, timeout) +/* const char *addr; +/* int block_mode; +/* int timeout; +/* DESCRIPTION +/* inet_connect connects to a TCP listener at +/* the specified address, and returns the resulting file descriptor. +/* +/* Specify an inet_windowsize value > 0 to override the TCP +/* window size that the client advertises to the server. +/* +/* Arguments: +/* .IP addr +/* The destination to connect to. The format is host:port. If no +/* host is specified, a port on the local host is assumed. +/* Host and port information may be given in numerical form +/* or as symbolical names. +/* .IP block_mode +/* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for +/* blocking mode. +/* .IP timeout +/* Bounds the number of seconds that the operation may take. Specify +/* a value <= 0 to disable the time limit. +/* DIAGNOSTICS +/* The result is -1 when the connection could not be made. +/* The nature of the error is available via the global \fIerrno\fR +/* variable. +/* Fatal errors: other system call failures. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System interfaces. */ + +#include <sys_defs.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <netdb.h> + +/* Utility library. */ + +#include "mymalloc.h" +#include "msg.h" +#include "iostuff.h" +#include "host_port.h" +#include "sane_connect.h" +#include "connect.h" +#include "timed_connect.h" +#include "myaddrinfo.h" +#include "sock_addr.h" +#include "inet_proto.h" + +static int inet_connect_one(struct addrinfo *, int, int); + +/* inet_connect - connect to TCP listener */ + +int inet_connect(const char *addr, int block_mode, int timeout) +{ + char *buf; + char *host; + char *port; + const char *parse_err; + struct addrinfo *res; + struct addrinfo *res0; + int aierr; + int sock; + MAI_HOSTADDR_STR hostaddr; + const INET_PROTO_INFO *proto_info; + int found; + + /* + * Translate address information to internal form. No host defaults to + * the local host. + */ + buf = mystrdup(addr); + if ((parse_err = host_port(buf, &host, "localhost", &port, (char *) 0)) != 0) + msg_fatal("%s: %s", addr, parse_err); + if ((aierr = hostname_to_sockaddr(host, port, SOCK_STREAM, &res0)) != 0) + msg_warn("host or service %s not found: %s", + addr, MAI_STRERROR(aierr)); + myfree(buf); + if (aierr) { + errno = EADDRNOTAVAIL; /* for up-stream "%m" */ + return (-1); + } + proto_info = inet_proto_info(); + for (sock = -1, found = 0, res = res0; res != 0; res = res->ai_next) { + + /* + * Safety net. + */ + if (strchr((char *) proto_info->sa_family_list, res->ai_family) == 0) { + msg_info("skipping address family %d for host %s", + res->ai_family, host); + continue; + } + found++; + + /* + * In case of multiple addresses, show what address we're trying now. + */ + if (msg_verbose) { + SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen, + &hostaddr, (MAI_SERVPORT_STR *) 0, 0); + msg_info("trying... [%s]", hostaddr.buf); + } + if ((sock = inet_connect_one(res, block_mode, timeout)) < 0) { + if (msg_verbose) + msg_info("%m"); + } else + break; + } + if (found == 0) + msg_fatal("host not found: %s", addr); + freeaddrinfo(res0); + return (sock); +} + +/* inet_connect_one - try to connect to one address */ + +static int inet_connect_one(struct addrinfo * res, int block_mode, int timeout) +{ + int sock; + + /* + * Create a client socket. + */ + sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol); + if (sock < 0) + return (-1); + + /* + * Window scaling workaround. + */ + if (inet_windowsize > 0) + set_inet_windowsize(sock, inet_windowsize); + + /* + * Timed connect. + */ + if (timeout > 0) { + non_blocking(sock, NON_BLOCKING); + if (timed_connect(sock, res->ai_addr, res->ai_addrlen, timeout) < 0) { + close(sock); + return (-1); + } + if (block_mode != NON_BLOCKING) + non_blocking(sock, block_mode); + return (sock); + } + + /* + * Maybe block until connected. + */ + else { + non_blocking(sock, block_mode); + if (sane_connect(sock, res->ai_addr, res->ai_addrlen) < 0 + && errno != EINPROGRESS) { + close(sock); + return (-1); + } + return (sock); + } +} |