/*
* socket.c -- socket library functions
*
+ * Copyright 1998 by Eric S. Raymond.
* For license terms, see the file COPYING in this directory.
*/
-#include <config.h>
-
+#include "config.h"
#include <stdio.h>
+#include <errno.h>
#include <string.h>
+#ifdef HAVE_MEMORY_H
+#include <memory.h>
+#endif /* HAVE_MEMORY_H */
#include <sys/types.h>
+#ifndef HAVE_NET_SOCKET_H
#include <sys/socket.h>
+#else
+#include <net/socket.h>
+#endif
#include <netinet/in.h>
+#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
+#endif
#include <netdb.h>
#if defined(STDC_HEADERS)
#include <stdlib.h>
#include <varargs.h>
#endif
#include "socket.h"
+#include "fetchmail.h"
+#include "i18n.h"
+
+/* Defines to allow BeOS to play nice... */
+#ifdef __BEOS__
+static char peeked;
+#define fm_close(a) closesocket(a)
+#define fm_write(a,b,c) send(a,b,c,0)
+#define fm_peek(a,b,c) recv(a,b,c,0)
+#define fm_read(a,b,c) recv(a,b,c,0)
+#else
+#define fm_close(a) close(a)
+#define fm_write(a,b,c) write(a,b,c)
+#define fm_peek(a,b,c) recv(a,b,c, MSG_PEEK)
+#define fm_read(a,b,c) read(a,b,c)
+#endif
+
+/* We need to define h_errno only if it is not already */
+#ifndef h_errno
+
+#ifdef HAVE_RES_SEARCH
+/* some versions of FreeBSD should declare this but don't */
+extern int h_errno;
+#else
+/* pretend we have h_errno to avoid some #ifdef's later */
+static int h_errno;
+#endif
+
+#endif /* ndef h_errno */
+
+#if NET_SECURITY
+#include <net/security.h>
+#endif /* NET_SECURITY */
+
+#ifdef HAVE_SOCKETPAIR
+const char **parse_plugin(const char *plugin, const char *host, const char *service)
+{ const char **argvec;
+ char *c, *p, *plugin_copy;
+ unsigned int s = 2 * sizeof(char*), i;
+
+ plugin_copy = strdup(plugin);
+ if (!plugin_copy)
+ {
+ report(stderr, _("fetchmail: malloc failed\n"));
+ return NULL;
+ }
+ for (c = p = plugin_copy; *c; c++)
+ { if (isspace(*c) && !isspace(*p))
+ s += sizeof(char*);
+ p = c;
+ }
+ argvec = malloc(s);
+ if (!argvec)
+ {
+ report(stderr, _("fetchmail: malloc failed\n"));
+ return NULL;
+ }
+ memset(argvec, 0, s);
+ for (c = p = plugin_copy, i = 0; *c; c++)
+ { if ((!isspace(*c)) && (c == p ? 1 : isspace(*p))) {
+ argvec[i] = c;
+ i++;
+ }
+ p = c;
+ }
+ for (c = plugin_copy; *c; c++)
+ { if (isspace(*c))
+ *c = 0;
+ }
+ for (i = 0; argvec[i]; i++)
+ { if (strcmp(argvec[i], "%h") == 0)
+ argvec[i] = host;
+ if (strcmp(argvec[i], "%p") == 0)
+ argvec[i] = service;
+ }
+ return argvec;
+}
+
+static int handle_plugin(const char *host,
+ const char *service, const char *plugin)
+/* get a socket mediated through a given external command */
+{
+ int fds[2];
+ char *const *argvec;
+ if (socketpair(AF_UNIX,SOCK_STREAM,0,fds))
+ {
+ report(stderr, _("fetchmail: socketpair failed\n"));
+ return -1;
+ }
+ switch (fork()) {
+ case -1:
+ /* error */
+ report(stderr, _("fetchmail: fork failed\n"));
+ return -1;
+ break;
+ case 0: /* child */
+ /* fds[1] is the parent's end; close it for proper EOF
+ ** detection */
+ (void) close(fds[1]);
+ if ( (dup2(fds[0],0) == -1) || (dup2(fds[0],1) == -1) ) {
+ report(stderr, _("dup2 failed\n"));
+ exit(1);
+ }
+ /* fds[0] is now connected to 0 and 1; close it */
+ (void) close(fds[0]);
+ if (outlevel >= O_VERBOSE)
+ report(stderr, _("running %s %s %s\n"), plugin, host, service);
+ argvec = (char *const *)parse_plugin(plugin,host,service);
+ execvp(*argvec, argvec);
+ report(stderr, _("execvp(%s) failed\n"), *argvec);
+ exit(0);
+ break;
+ default: /* parent */
+ /* NOP */
+ break;
+ }
+ /* fds[0] is the child's end; close it for proper EOF detection */
+ (void) close(fds[0]);
+ return fds[1];
+}
+#endif /* HAVE_SOCKETPAIR */
+
+#ifdef __UNUSED__
+#include <sys/time.h>
+
+int SockCheckOpen(int fd)
+/* poll given socket; is it selectable? */
+{
+ fd_set r, w, e;
+ int rt;
+ struct timeval tv;
+
+ for (;;)
+ {
+ FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
+ FD_SET(fd, &e);
+
+ tv.tv_sec = 0; tv.tv_usec = 0;
+ rt = select(fd+1, &r, &w, &e, &tv);
+ if (rt == -1 && (errno != EAGAIN && errno != EINTR))
+ return 0;
+ if (rt != -1)
+ return 1;
+ }
+}
+#endif /* __UNUSED__ */
+
+#if INET6_ENABLE
+int SockOpen(const char *host, const char *service, const char *options,
+ const char *plugin)
+{
+ struct addrinfo *ai, *ai0, req;
+ int i;
+#if NET_SECURITY
+ void *request = NULL;
+ int requestlen;
+#endif /* NET_SECURITY */
+
+#ifdef HAVE_SOCKETPAIR
+ if (plugin)
+ return handle_plugin(host,service,plugin);
+#endif /* HAVE_SOCKETPAIR */
+ memset(&req, 0, sizeof(struct addrinfo));
+ req.ai_socktype = SOCK_STREAM;
+
+ if (getaddrinfo(host, service, &req, &ai0)) {
+ report(stderr, _("fetchmail: getaddrinfo(%s.%s)\n"), host,service);
+ return -1;
+ }
+
+#if NET_SECURITY
+ if (!options)
+ requestlen = 0;
+ else
+ if (net_security_strtorequest((char *)options, &request, &requestlen))
+ goto ret;
+ i = inner_connect(ai0, request, requestlen, NULL, NULL, "fetchmail", NULL);
+ if (request)
+ free(request);
+
+ ret:
+#else /* NET_SECURITY */
+#ifdef HAVE_INNER_CONNECT
+ i = inner_connect(ai0, NULL, 0, NULL, NULL, "fetchmail", NULL);
+ if (i >= 0)
+ break;
+#else
+ i = -1;
+ for (ai = ai0; ai; ai = ai->ai_next) {
+ i = socket(ai->ai_family, ai->ai_socktype, 0);
+ if (i < 0)
+ continue;
+ if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) {
+ fm_close(i);
+ i = -1;
+ continue;
+ }
+ break;
+ }
+#endif
+#endif /* NET_SECURITY */
+
+ freeaddrinfo(ai0);
+
+ return i;
+}
+#else /* INET6_ENABLE */
+#ifndef HAVE_INET_ATON
#ifndef INADDR_NONE
#ifdef INADDR_BROADCAST
#define INADDR_NONE INADDR_BROADCAST
#define INADDR_NONE -1
#endif
#endif
+#endif /* HAVE_INET_ATON */
-/*
- * Size of buffer for internal buffering read function
- * don't increase beyond the maximum atomic read/write size for
- * your sockets, or you'll take a potentially huge performance hit
- */
-#define INTERNAL_BUFSIZE 2048
-
-FILE *sockopen(char *host, int clientPort)
+int SockOpen(const char *host, int clientPort, const char *options,
+ const char *plugin)
{
- int sock;
+ int sock = -1; /* pacify -Wall */
+#ifndef HAVE_INET_ATON
unsigned long inaddr;
- struct sockaddr_in ad;
+#endif /* HAVE_INET_ATON */
+ struct sockaddr_in ad, **pptr;
struct hostent *hp;
- FILE *fp;
+
+#ifdef HAVE_SOCKETPAIR
+ if (plugin) {
+ char buf[10];
+ sprintf(buf,"%d",clientPort);
+ return handle_plugin(host,buf,plugin);
+ }
+#endif /* HAVE_SOCKETPAIR */
memset(&ad, 0, sizeof(ad));
ad.sin_family = AF_INET;
+ /* we'll accept a quad address */
+#ifndef HAVE_INET_ATON
inaddr = inet_addr(host);
if (inaddr != INADDR_NONE)
+ {
memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
- else
+#else
+ if (inet_aton(host, &ad.sin_addr))
{
+#endif /* HAVE_INET_ATON */
+ ad.sin_port = htons(clientPort);
+
+ sock = socket(AF_INET, SOCK_STREAM, 0);
+ if (sock < 0)
+ {
+ h_errno = 0;
+ return -1;
+ }
+ if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
+ {
+ int olderr = errno;
+ fm_close(sock); /* don't use SockClose, no traffic yet */
+ h_errno = 0;
+ errno = olderr;
+ return -1;
+ }
+#ifndef HAVE_INET_ATON
+ }
+#else
+ }
+#endif /* HAVE_INET_ATON */
+ else {
hp = gethostbyname(host);
+
if (hp == NULL)
- return (FILE *)NULL;
- memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);
+ {
+ errno = 0;
+ return -1;
+ }
+ /*
+ * Add a check to make sure the address has a valid IPv4 or IPv6
+ * length. This prevents buffer spamming by a broken DNS.
+ */
+ if(hp->h_length != 4 && hp->h_length != 8)
+ {
+ h_errno = errno = 0;
+ report(stderr,
+ _("fetchmail: illegal address length received for host %s\n"),host);
+ return -1;
+ }
+ /*
+ * Try all addresses of a possibly multihomed host until we get
+ * a successful connect or until we run out of addresses.
+ */
+ pptr = (struct sockaddr_in **)hp->h_addr_list;
+ for(; *pptr != NULL; pptr++)
+ {
+ sock = socket(AF_INET, SOCK_STREAM, 0);
+ if (sock < 0)
+ {
+ h_errno = 0;
+ return -1;
+ }
+ ad.sin_port = htons(clientPort);
+ memcpy(&ad.sin_addr, *pptr, sizeof(struct in_addr));
+ if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) == 0)
+ break; /* success */
+ fm_close(sock); /* don't use SockClose, no traffic yet */
+ memset(&ad, 0, sizeof(ad));
+ ad.sin_family = AF_INET;
+ }
+ if(*pptr == NULL)
+ {
+ int olderr = errno;
+ fm_close(sock); /* don't use SockClose, no traffic yet */
+ h_errno = 0;
+ errno = olderr;
+ return -1;
+ }
}
- ad.sin_port = htons(clientPort);
-
- sock = socket(AF_INET, SOCK_STREAM, 0);
- if (sock < 0)
- return (FILE *)NULL;
- if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
+
+ return(sock);
+}
+#endif /* INET6_ENABLE */
+
+
+#if defined(HAVE_STDARG_H)
+int SockPrintf(int sock, const char* format, ...)
+{
+#else
+int SockPrintf(sock,format,va_alist)
+int sock;
+char *format;
+va_dcl {
+#endif
+
+ va_list ap;
+ char buf[8192];
+
+#if defined(HAVE_STDARG_H)
+ va_start(ap, format) ;
+#else
+ va_start(ap);
+#endif
+#ifdef HAVE_VSNPRINTF
+ vsnprintf(buf, sizeof(buf), format, ap);
+#else
+ vsprintf(buf, format, ap);
+#endif
+ va_end(ap);
+ return SockWrite(sock, buf, strlen(buf));
+
+}
+
+#ifdef SSL_ENABLE
+#include "openssl/ssl.h"
+#include "openssl/err.h"
+#include "openssl/pem.h"
+#include "openssl/x509.h"
+
+static SSL_CTX *_ctx = NULL;
+static SSL *_ssl_context[FD_SETSIZE];
+
+SSL *SSLGetContext( int );
+#endif /* SSL_ENABLE */
+
+int SockWrite(int sock, char *buf, int len)
+{
+ int n, wrlen = 0;
+#ifdef SSL_ENABLE
+ SSL *ssl;
+#endif
+
+ while (len)
{
- close(sock);
- return (FILE *)NULL;
+#ifdef SSL_ENABLE
+ if( NULL != ( ssl = SSLGetContext( sock ) ) )
+ n = SSL_write(ssl, buf, len);
+ else
+ n = fm_write(sock, buf, len);
+#else
+ n = fm_write(sock, buf, len);
+#endif
+ if (n <= 0)
+ return -1;
+ len -= n;
+ wrlen += n;
+ buf += n;
+ }
+ return wrlen;
+}
+
+int SockRead(int sock, char *buf, int len)
+{
+ char *newline, *bp = buf;
+ int n;
+#ifdef SSL_ENABLE
+ SSL *ssl;
+#endif
+
+ if (--len < 1)
+ return(-1);
+#ifdef __BEOS__
+ if (peeked != 0){
+ (*bp) = peeked;
+ bp++;
+ len--;
+ peeked = 0;
+ }
+#endif
+ do {
+ /*
+ * The reason for these gymnastics is that we want two things:
+ * (1) to read \n-terminated lines,
+ * (2) to return the true length of data read, even if the
+ * data coming in has embedded NULS.
+ */
+#ifdef SSL_ENABLE
+ if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
+ /* Hack alert! */
+ /* OK... SSL_peek works a little different from MSG_PEEK
+ Problem is that SSL_peek can return 0 if there
+ is no data currently available. If, on the other
+ hand, we loose the socket, we also get a zero, but
+ the SSL_read then SEGFAULTS! To deal with this,
+ we'll check the error code any time we get a return
+ of zero from SSL_peek. If we have an error, we bail.
+ If we don't, we read one character in SSL_read and
+ loop. This should continue to work even if they
+ later change the behavior of SSL_peek
+ to "fix" this problem... :-( */
+ if ((n = SSL_peek(ssl, bp, len)) < 0) {
+ return(-1);
+ }
+ if( 0 == n ) {
+ /* SSL_peek says no data... Does he mean no data
+ or did the connection blow up? If we got an error
+ then bail! */
+ if( 0 != ( n = ERR_get_error() ) ) {
+ return -1;
+ }
+ /* We didn't get an error so read at least one
+ character at this point and loop */
+ n = 1;
+ /* Make sure newline start out NULL!
+ * We don't have a string to pass through
+ * the strchr at this point yet */
+ newline = NULL;
+ } else if ((newline = memchr(bp, '\n', n)) != NULL)
+ n = newline - bp + 1;
+ if ((n = SSL_read(ssl, bp, n)) == -1) {
+ return(-1);
+ }
+ /* Check for case where our single character turned out to
+ * be a newline... (It wasn't going to get caught by
+ * the strchr above if it came from the hack... ). */
+ if( NULL == newline && 1 == n && '\n' == *bp ) {
+ /* Got our newline - this will break
+ out of the loop now */
+ newline = bp;
+ }
+ } else {
+ if ((n = fm_peek(sock, bp, len)) <= 0)
+ return(-1);
+ if ((newline = memchr(bp, '\n', n)) != NULL)
+ n = newline - bp + 1;
+ if ((n = fm_read(sock, bp, n)) == -1)
+ return(-1);
+ }
+#else
+
+#ifdef __BEOS__
+ if ((n = fm_read(sock, bp, 1)) <= 0)
+#else
+ if ((n = fm_peek(sock, bp, len)) <= 0)
+#endif
+ return (-1);
+ if ((newline = memchr(bp, '\n', n)) != NULL)
+ n = newline - bp + 1;
+#ifndef __BEOS__
+ if ((n = fm_read(sock, bp, n)) == -1)
+ return(-1);
+#endif /* __BEOS__ */
+#endif
+ bp += n;
+ len -= n;
+ } while
+ (!newline && len);
+ *bp = '\0';
+ return bp - buf;
+}
+
+int SockPeek(int sock)
+/* peek at the next socket character without actually reading it */
+{
+ int n;
+ char ch;
+#ifdef SSL_ENABLE
+ SSL *ssl;
+#endif
+
+#ifdef SSL_ENABLE
+ if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
+ n = SSL_peek(ssl, &ch, 1);
+ if( 0 == n ) {
+ /* This code really needs to implement a "hold back"
+ * to simulate a functioning SSL_peek()... sigh...
+ * Has to be coordinated with the read code above.
+ * Next on the list todo... */
+
+ /* SSL_peek says no data... Does he mean no data
+ or did the connection blow up? If we got an error
+ then bail! */
+ if( 0 != ( n = ERR_get_error() ) ) {
+ return -1;
+ }
+
+ /* Haven't seen this case actually occur, but...
+ if the problem in SockRead can occur, this should
+ be possible... Just not sure what to do here.
+ This should be a safe "punt" the "peek" but don't
+ "punt" the "session"... */
+
+ return 0; /* Give him a '\0' character */
+ }
+ } else {
+ n = fm_peek(sock, &ch, 1);
+ }
+#else
+
+ n = fm_peek(sock, &ch, 1);
+
+#endif /* SSL_ENABLE */
+ if (n == -1)
+ return -1;
+
+#ifdef __BEOS__
+ peeked = ch;
+#endif
+ return(ch);
+}
+
+#ifdef SSL_ENABLE
+
+static char *_ssl_server_cname = NULL;
+
+SSL *SSLGetContext( int sock )
+{
+ /* If SSLOpen has never initialized - just return NULL */
+ if( NULL == _ctx )
+ return NULL;
+
+ if( sock < 0 || sock > FD_SETSIZE )
+ return NULL;
+ return _ssl_context[sock];
+}
+
+
+int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx )
+{
+ char buf[260];
+ char cbuf[260];
+ char ibuf[260];
+ char *str_ptr;
+ X509 *x509_cert;
+ int err, depth;
+
+ x509_cert = X509_STORE_CTX_get_current_cert(ctx);
+ err = X509_STORE_CTX_get_error(ctx);
+ depth = X509_STORE_CTX_get_error_depth(ctx);
+
+ X509_NAME_oneline(X509_get_subject_name(x509_cert), buf, 256);
+ X509_NAME_oneline(X509_get_issuer_name(x509_cert), ibuf, 256);
+
+ /* Just to be sure those buffers are terminated... I think the
+ X509 libraries do, but... */
+ buf[256] = ibuf[256] = '\0';
+
+ if (depth == 0) {
+ if( ( str_ptr = strstr( ibuf, "/O=" ) ) ) {
+ str_ptr += 3;
+ strcpy( cbuf, str_ptr );
+ if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
+ *str_ptr = '\0';
+ }
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Issuer Organization: %s\n", cbuf );
+ } else {
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Unknown Organization\n", cbuf );
+ }
+ if( ( str_ptr = strstr( ibuf, "/CN=" ) ) ) {
+ str_ptr += 4;
+ strcpy( cbuf, str_ptr );
+ if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
+ *str_ptr = '\0';
+ }
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Issuer CommonName: %s\n", cbuf );
+ } else {
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Unknown Issuer CommonName\n", cbuf );
+ }
+ if( ( str_ptr = strstr( buf, "/CN=" ) ) ) {
+ str_ptr += 4;
+ strcpy( cbuf, str_ptr );
+ if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
+ *str_ptr = '\0';
+ }
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Server CommonName: %s\n", cbuf );
+ /* Should we have some wildcarding here? */
+ if ( NULL != _ssl_server_cname
+ && 0 != strcasecmp( cbuf, _ssl_server_cname ) ) {
+ report(stdout,
+ "Server CommonName mismatch: %s != %s\n",
+ cbuf, _ssl_server_cname );
+ }
+ } else {
+ if (outlevel == O_VERBOSE)
+ report(stdout, "Unknown Server CommonName\n", cbuf );
+ }
+ }
+
+ switch (ctx->error) {
+ case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
+ X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert), buf, 256);
+ report(stdout, _("unknown issuer= %s"), buf);
+ break;
+ case X509_V_ERR_CERT_NOT_YET_VALID:
+ case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
+ report(stderr, _("Server Certificate not yet valid"));
+ break;
+ case X509_V_ERR_CERT_HAS_EXPIRED:
+ case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
+ report(stderr, _("Server Certificate expired"));
+ break;
+ }
+ /* We are not requiring or validating server or issuer id's as yet */
+ /* Always return OK from here */
+ ok_return = 1;
+ return( ok_return );
+}
+
+
+/* performs initial SSL handshake over the connected socket
+ * uses SSL *ssl global variable, which is currently defined
+ * in this file
+ */
+int SSLOpen(int sock, char *mycert, char *mykey, char *servercname )
+{
+ SSL_load_error_strings();
+ SSLeay_add_ssl_algorithms();
+
+ if( sock < 0 || sock > FD_SETSIZE ) {
+ report(stderr, "File descriptor out of range for SSL" );
+ return( -1 );
+ }
+
+ if( ! _ctx ) {
+ /* Be picky and make sure the memory is cleared */
+ memset( _ssl_context, 0, sizeof( _ssl_context ) );
+ _ctx = SSL_CTX_new(SSLv23_client_method());
+ if(_ctx == NULL) {
+ ERR_print_errors_fp(stderr);
+ return(-1);
+ }
+ }
+
+ _ssl_context[sock] = SSL_new(_ctx);
+
+ if(_ssl_context[sock] == NULL) {
+ ERR_print_errors_fp(stderr);
+ return(-1);
+ }
+
+ /* This static is for the verify callback */
+ _ssl_server_cname = servercname;
+
+ SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_verify_callback);
+
+ if( mycert || mykey ) {
+
+ /* Ok... He has a certificate file defined, so lets declare it. If
+ * he does NOT have a separate certificate and private key file then
+ * assume that it's a combined key and certificate file.
+ */
+ if( !mykey )
+ mykey = mycert;
+ if( !mycert )
+ mycert = mykey;
+ SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
+ SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
+ }
+
+ SSL_set_fd(_ssl_context[sock], sock);
+
+ if(SSL_connect(_ssl_context[sock]) == -1) {
+ ERR_print_errors_fp(stderr);
+ return(-1);
+ }
+
+ return(0);
+}
+#endif
+
+int SockClose(int sock)
+/* close a socket gracefully */
+{
+#ifdef SSL_ENABLE
+ SSL *ssl;
+
+ if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
+ /* Clean up the SSL stack */
+ SSL_free( _ssl_context[sock] );
+ _ssl_context[sock] = NULL;
}
- fp = fdopen(sock, "r+");
+#endif
- /* the point of all this mishigoss ... dynamic per-stream buffering */
- setvbuf(fp, NULL, _IOLBF, INTERNAL_BUFSIZE);
+#ifdef __UNUSED__
+ /*
+ * This hangs in RedHat 6.2 after fetchmail runs for a while a
+ * FIN_WAIT2 comes up in netstat and fetchmail never returns from
+ * the recv system call. (Reported from jtnews
+ * <jtnews@bellatlantic.net>, Wed, 24 May 2000 21:26:02.)
+ *
+ * Half-close the connection first so the other end gets notified.
+ *
+ * This stops sends but allows receives (effectively, it sends a
+ * TCP <FIN>). */
+ if (shutdown(sock, 1) == 0) {
+ char ch;
+ /* If there is any data still waiting in the queue, discard it.
+ * Call recv() until either it returns 0 (meaning we received a FIN)
+ * or any error occurs. This makes sure all data sent by the other
+ * side is acknowledged at the TCP level.
+ */
+ if (fm_peek(sock, &ch, 1) > 0)
+ while (fm_read(sock, &ch, 1) > 0)
+ continue;
+ }
+#endif /* __UNUSED__ */
- return(fp);
+ /* if there's an error closing at this point, not much we can do */
+ return(fm_close(sock)); /* this is guarded */
}
#ifdef MAIN
/*
- * Use the chargen service to test buffering directly.
- */
+ * Use the chargen service to test input buffering directly.
+ * You may have to uncomment the `chargen' service description in your
+ * inetd.conf (and then SIGHUP inetd) for this to work. */
main()
{
- FILE *fp = sockopen("localhost", 19);
+ int sock = SockOpen("localhost", 19, NULL);
char buf[80];
- while (fgets(buf, sizeof(buf)-1, fp))
- fputs(buf, stdout);
+ while (SockRead(sock, buf, sizeof(buf)-1))
+ SockWrite(1, buf, strlen(buf));
+ SockClose(sock);
}
#endif /* MAIN */