+static int
+netsec_fillread(netsec_context *nsc, char **errstr)
+{
+ unsigned char *end;
+ char *readbuf;
+ size_t readbufsize, remaining, startoffset;
+ int rc;
+
+ /*
+ * If inbuflen is zero, that means the buffer has been emptied
+ * completely. In that case move inptr back to the start.
+ */
+
+ if (nsc->ns_inbuflen == 0) {
+ nsc->ns_inptr = nsc->ns_inbuffer;
+ }
+
+#if defined(CYRUS_SASL) || defined(TLS_SUPPORT)
+retry:
+#endif /* CYRUS_SASL || TLS_SUPPORT */
+ /*
+ * If we are using TLS and there's anything pending, then skip the
+ * select call
+ */
+#ifdef TLS_SUPPORT
+ if (!nsc->tls_active || BIO_pending(nsc->ssl_io) == 0)
+#endif /* TLS_SUPPORT */
+ {
+ struct timeval tv;
+ fd_set rfds;
+
+ FD_ZERO(&rfds);
+ FD_SET(nsc->ns_readfd, &rfds);
+
+ tv.tv_sec = nsc->ns_timeout;
+ tv.tv_usec = 0;
+
+ rc = select(nsc->ns_readfd + 1, &rfds, NULL, NULL, &tv);
+
+ if (rc == -1) {
+ netsec_err(errstr, "select() while reading failed: %s",
+ strerror(errno));
+ return NOTOK;
+ }
+
+ if (rc == 0) {
+ netsec_err(errstr, "read() timed out after %d seconds",
+ nsc->ns_timeout);
+ return NOTOK;
+ }
+
+ /*
+ * At this point, we know that rc is 1, so there's not even any
+ * point to check to see if our descriptor is set in rfds.
+ */
+ }
+
+ /*
+ * Some explanation:
+ *
+ * startoffset is the offset from the beginning of the input
+ * buffer to data that is in our input buffer, but has not yet
+ * been consumed. This can be non-zero if functions like
+ * netsec_readline() leave leftover data.
+ *
+ * remaining is the remaining amount of unconsumed data in the input
+ * buffer.
+ *
+ * end is a pointer to the end of the valid data + 1; it's where
+ * the next read should go.
+ */
+
+ startoffset = nsc->ns_inptr - nsc->ns_inbuffer;
+ remaining = nsc->ns_inbufsize - (startoffset + nsc->ns_inbuflen);
+ end = nsc->ns_inptr + nsc->ns_inbuflen;
+
+ /*
+ * If we're past the halfway point in our read buffers, shuffle everything
+ * back to the beginning.
+ */
+
+ if (startoffset > nsc->ns_inbufsize / 2) {
+ memmove(nsc->ns_inbuffer, nsc->ns_inptr, nsc->ns_inbuflen);
+ nsc->ns_inptr = nsc->ns_inbuffer;
+ startoffset = 0;
+ remaining = nsc->ns_inbufsize - nsc->ns_inbuflen;
+ end = nsc->ns_inptr + nsc->ns_inbuflen;
+ }
+
+ /*
+ * If we are using TLS, then just read via the BIO. But we still
+ * use our local buffer.
+ */
+#ifdef TLS_SUPPORT
+ if (nsc->tls_active) {
+ rc = BIO_read(nsc->ssl_io, end, remaining);
+ if (rc == 0) {
+ SSL *ssl;
+ int errcode;
+
+ /*
+ * Check to see if we're supposed to retry; if so,
+ * then go back and read again.
+ */
+
+ if (BIO_should_retry(nsc->ssl_io))
+ goto retry;
+
+ /*
+ * Okay, fine. Get the real error out of the SSL context.
+ */
+
+ if (BIO_get_ssl(nsc->ssl_io, &ssl) < 1) {
+ netsec_err(errstr, "SSL_read() returned 0, but cannot "
+ "retrieve SSL context");
+ return NOTOK;
+ }
+
+ errcode = SSL_get_error(ssl, rc);
+ if (errcode == SSL_ERROR_ZERO_RETURN) {
+ netsec_err(errstr, "TLS peer closed remote connection");
+ } else {
+ netsec_err(errstr, "TLS network read failed: %s",
+ ERR_error_string(ERR_peek_last_error(), NULL));
+ }
+ if (nsc->ns_snoop)
+ ERR_print_errors_fp(stderr);
+ return NOTOK;
+ }
+ if (rc < 0) {
+ /* Definitely an error */
+ netsec_err(errstr, "Read on TLS connection failed: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ return NOTOK;
+ }
+
+ nsc->ns_inbuflen += rc;
+
+ return OK;
+ }
+#endif /* TLS_SUPPORT */
+
+ /*
+ * Okay, time to read some data. Either we're just doing it straight
+ * or we're passing it through sasl_decode() first.
+ */
+
+#ifdef CYRUS_SASL
+ if (nsc->sasl_seclayer) {
+ readbuf = nsc->sasl_tmpbuf;
+ readbufsize = nsc->sasl_maxbufsize;
+ } else
+#endif /* CYRUS_SASL */
+ {
+ readbuf = (char *) end;
+ readbufsize = remaining;
+ }
+
+ /*
+ * At this point, we should have active data on the connection (see
+ * select() above) so this read SHOULDN'T block. Hopefully.
+ */
+
+ rc = read(nsc->ns_readfd, readbuf, readbufsize);
+
+ if (rc == 0) {
+ netsec_err(errstr, "Received EOF on network read");
+ return NOTOK;
+ }
+
+ if (rc < 0) {
+ netsec_err(errstr, "Network read failed: %s", strerror(errno));
+ return NOTOK;
+ }
+
+ /*
+ * Okay, so we've had a successful read. If we are doing SASL security
+ * layers, pass this through sasl_decode(). sasl_decode() can return
+ * 0 bytes decoded; if that happens, jump back to the beginning. Otherwise
+ * we can just update our length pointer.
+ */
+
+#ifdef CYRUS_SASL
+ if (nsc->sasl_seclayer) {
+ const char *tmpout;
+ unsigned int tmpoutlen;
+
+ rc = sasl_decode(nsc->sasl_conn, nsc->sasl_tmpbuf, rc,
+ &tmpout, &tmpoutlen);
+
+ if (rc != SASL_OK) {
+ netsec_err(errstr, "Unable to decode SASL network data: %s",
+ sasl_errdetail(nsc->sasl_conn));
+ return NOTOK;
+ }
+
+ if (tmpoutlen == 0)
+ goto retry;
+
+ /*
+ * Just in case ...
+ */
+
+ if (tmpoutlen > remaining) {
+ netsec_err(errstr, "Internal error: SASL decode buffer overflow!");
+ return NOTOK;
+ }
+
+ memcpy(end, tmpout, tmpoutlen);
+
+ nsc->ns_inbuflen += tmpoutlen;
+ } else
+#endif /* CYRUS_SASL */
+ nsc->ns_inbuflen += rc;
+
+ return OK;
+}
+
+/*
+ * Write data to our network connection. Really, fill up the buffer as
+ * much as we can, and flush it out if necessary. netsec_flush() does
+ * the real work.
+ */
+
+int
+netsec_write(netsec_context *nsc, const void *buffer, size_t size,
+ char **errstr)
+{
+ const unsigned char *bufptr = buffer;
+ int rc, remaining;
+
+ /* Just in case */
+
+ if (size == 0)
+ return OK;
+
+ /*
+ * Run a loop copying in data to our local buffer; when we're done with
+ * any buffer overflows then just copy any remaining data in.
+ */
+
+ while ((int) size >= (remaining = nsc->ns_outbufsize - nsc->ns_outbuflen)) {
+ memcpy(nsc->ns_outptr, bufptr, remaining);
+
+ /*
+ * In theory I should increment outptr, but netsec_flush just resets
+ * it anyway.
+ */
+ nsc->ns_outbuflen = nsc->ns_outbufsize;
+
+ rc = netsec_flush(nsc, errstr);
+
+ if (rc != OK)
+ return NOTOK;
+
+ bufptr += remaining;
+ size -= remaining;
+ }
+
+ /*
+ * Copy any leftover data into the buffer.
+ */
+
+ if (size > 0) {
+ memcpy(nsc->ns_outptr, bufptr, size);
+ nsc->ns_outptr += size;
+ nsc->ns_outbuflen += size;
+ }
+
+ return OK;
+}
+
+/*
+ * Our network printf() routine, which really just calls netsec_vprintf().
+ */
+
+int
+netsec_printf(netsec_context *nsc, char **errstr, const char *format, ...)
+{
+ va_list ap;
+ int rc;
+
+ va_start(ap, format);
+ rc = netsec_vprintf(nsc, errstr, format, ap);
+ va_end(ap);
+
+ return rc;
+}
+
+/*
+ * Write bytes to the network using printf()-style formatting.
+ *
+ * Again, for the most part copy stuff into our buffer to be flushed
+ * out later.
+ */
+
+int
+netsec_vprintf(netsec_context *nsc, char **errstr, const char *format,
+ va_list ap)
+{
+ int rc;
+
+ /*
+ * Cheat a little. If we can fit the data into our outgoing buffer,
+ * great! If not, generate a flush and retry once.
+ */
+
+retry:
+ rc = vsnprintf((char *) nsc->ns_outptr,
+ nsc->ns_outbufsize - nsc->ns_outbuflen, format, ap);
+
+ if (rc >= (int) (nsc->ns_outbufsize - nsc->ns_outbuflen)) {
+ /*
+ * This means we have an overflow. Note that we don't actually
+ * make use of the terminating NUL, but according to the spec
+ * vsnprintf() won't write to the last byte in the string; that's
+ * why we have to use >= in the comparison above.
+ */
+ if (nsc->ns_outbuffer == nsc->ns_outptr) {
+ /*
+ * Whoops, if the buffer pointer was the same as the start of the
+ * buffer, that means we overflowed the internal buffer.
+ * At that point, just give up.
+ */
+ netsec_err(errstr, "Internal error: wanted to printf() a total of "
+ "%d bytes, but our buffer size was only %d bytes",
+ rc, nsc->ns_outbufsize);
+ return NOTOK;
+ }
+ /*
+ * Generate a flush (which may be inefficient, but hopefully
+ * it isn't) and then try again.
+ */
+ if (netsec_flush(nsc, errstr) != OK)
+ return NOTOK;
+ /*
+ * After this, outbuffer should == outptr, so we shouldn't
+ * hit this next time around.
+ */
+ goto retry;
+ }
+
+ if (nsc->ns_snoop) {
+ int outlen = rc;
+ if (outlen > 0 && nsc->ns_outptr[outlen - 1] == '\n') {
+ outlen--;
+ if (outlen > 0 && nsc->ns_outptr[outlen - 1] == '\r')
+ outlen--;
+ } else {
+ nsc->ns_snoop_noend = 1;
+ }
+ if (outlen > 0 || nsc->ns_snoop_noend == 0) {
+#ifdef CYRUS_SASL
+ if (nsc->sasl_seclayer)
+ fprintf(stderr, "(sasl-encrypted) ");
+#endif /* CYRUS_SASL */
+#ifdef TLS_SUPPORT
+ if (nsc->tls_active)
+ fprintf(stderr, "(tls-encrypted) ");
+#endif /* TLS_SUPPORT */
+ fprintf(stderr, "=> ");
+ if (nsc->ns_snoop_cb)
+ nsc->ns_snoop_cb(nsc, (char *) nsc->ns_outptr, outlen,
+ nsc->ns_snoop_context);
+ else
+ fprintf(stderr, "%.*s\n", outlen, nsc->ns_outptr);
+ } else {
+ nsc->ns_snoop_noend = 0;
+ }
+ }
+
+ nsc->ns_outptr += rc;
+ nsc->ns_outbuflen += rc;
+
+ return OK;
+}
+
+/*
+ * Flush out any buffered data in our output buffers. This routine is
+ * actually where the real network writes take place.
+ */
+
+int
+netsec_flush(netsec_context *nsc, char **errstr)
+{
+ const char *netoutbuf = (const char *) nsc->ns_outbuffer;
+ unsigned int netoutlen = nsc->ns_outbuflen;
+ int rc;
+
+ /*
+ * Small optimization
+ */
+
+ if (netoutlen == 0)
+ return OK;
+
+ /*
+ * If SASL security layers are in effect, run the data through
+ * sasl_encode() first.
+ */
+#ifdef CYRUS_SASL
+ if (nsc->sasl_seclayer) {
+ rc = sasl_encode(nsc->sasl_conn, (const char *) nsc->ns_outbuffer,
+ nsc->ns_outbuflen, &netoutbuf, &netoutlen);
+
+ if (rc != SASL_OK) {
+ netsec_err(errstr, "SASL data encoding failed: %s",
+ sasl_errdetail(nsc->sasl_conn));
+ return NOTOK;
+ }
+
+ }
+#endif /* CYRUS_SASL */
projects / nmh / blobdiff