Introduce "BIO pairs", which (when finished) will relay data

so that the SSL library can be used for applications that
have to handle all the actual I/O themselves.

1 files changed, 258 insertions, 0 deletions

diff --git a/crypto/bio/bss_bio.c b/crypto/bio/bss_bio.c
new file mode 100644
index 0000000000..5b60f541a1
--- /dev/null
+++ b/crypto/bio/bss_bio.c
@@ -0,0 +1,258 @@
+/* crypto/bio/bss_bio.c  -*- Mode: C; c-file-style: "eay" -*- */
+
+/*  *** Not yet finished (or even tested). *** */
+
+/* Special method for a BIO where the other endpoint is also a BIO
+ * of this kind, handled by the same thread.
+ * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces
+ * for which no specific BIO method is available. */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/crypto.h>
+
+static int bio_new(BIO *bio);
+static int bio_free(BIO *bio);
+static int bio_read(BIO *bio, char *buf, int size);
+static int bio_write(BIO *bio, char *buf, int num);
+static long bio_ctrl(BIO *bio, int cmd, long num, char *ptr);
+static int bio_puts(BIO *bio, char *str);
+
+static int bio_make_pair(BIO *bio1, BIO *bio2);
+static void bio_destroy_pair(BIO *bio);
+
+static BIO_METHOD methods_biop =
+{
+	BIO_TYPE_BIO,
+	"BIO pair",
+	bio_write,
+	bio_read,
+	bio_puts,
+	NULL /* no bio_gets */,
+	bio_ctrl,
+	bio_new,
+	bio_free
+};
+
+BIO_METHOD *BIO_s_bio(void)
+	{
+	return &methods_biop;
+	}
+
+struct bio_bio_st
+{
+	BIO *peer;     /* NULL if buf == NULL.
+					* If peer != NULL, then peer->ptr is also a bio_bio_st,
+					* and its "peer" member points back to us. */
+	
+	/* This is for what we write (i.e. reading uses peer's struct): */
+	int closed;    /* valid iff peer != NULL */
+	size_t len;    /* valid iff buf != NULL; 0 if peer == NULL */
+	size_t offset; /* valid iff buf != NULL; 0 if len == 0 */
+	size_t size;
+	char *buf;     /* "size" elements (if != NULL) */
+};
+
+static int bio_new(BIO *bio)
+	{
+	struct bio_bio_st *b;
+	
+	b = Malloc(sizeof *b);
+	if (b == NULL)
+		return 0;
+
+	b->peer = NULL;
+	b->size = 17*1024; /* enough for one TLS record (just a default) */
+	b->buf = NULL;
+
+	return 1;
+	}
+
+
+static int bio_free(BIO *bio)
+	{
+	struct bio_bio_st *b;
+
+	if (bio == NULL)
+		return 0;
+	b = bio->ptr;
+
+	assert(b != NULL);
+
+	if (b->peer)
+		bio_destroy_pair(bio);
+	
+	if (b->buf != NULL)
+		{
+		Free(b->buf);
+		}
+
+	Free(b);
+
+	return 1;
+	}
+
+
+
+static int bio_read(BIO *bio, char *buf, int size)
+	{
+	/* XXX */
+	return -1;
+	}
+
+static int bio_write(BIO *bio, char *buf, int num)
+	{
+	/* XXX */
+	return -1;
+	}
+	
+static long bio_ctrl(BIO *bio, int cmd, long num, char *ptr)
+	{
+	long ret;
+	struct bio_bio_st *b = bio->ptr;
+	
+	assert(b != NULL);
+
+	switch (cmd)
+		{
+		/* XXX Additional commands: */
+		/* - Set buffer size */
+		/* - make pair */
+		/* - destroy pair */
+		/* - get number of bytes that the next write will accept */
+		/* - send "close" */
+
+	case BIO_CTRL_RESET:
+		if (b->buf != NULL)
+			{
+			b->len = 0;
+			b->offset = 0;
+			}
+		ret = 0;
+		break;		
+
+	case BIO_CTRL_GET_CLOSE:
+		ret = bio->shutdown;
+		break;
+
+	case BIO_CTRL_SET_CLOSE:
+		bio->shutdown = (int) num;
+		ret = 1;
+		break;
+
+	case BIO_CTRL_PENDING:
+		if (b->peer != NULL)
+			{
+			struct bio_bio_st *peer_b =b->peer->ptr;
+			
+			ret = (long) peer_b->len;
+			}
+		else
+			ret = 0;
+		break;
+
+	case BIO_CTRL_WPENDING:
+		if (b->buf != NULL)
+			ret = (long) b->len;
+		else
+			ret = 0;
+		break;
+
+	case BIO_CTRL_DUP:
+		/* XXX */
+
+	case BIO_CTRL_FLUSH:
+		ret = 1;
+		break;
+
+	default:
+		ret = 0;
+		}
+	return ret;
+	}
+
+static int bio_puts(BIO *bio, char *str)
+	{
+	return bio_write(bio, str, strlen(str));
+	}
+
+
+
+static int bio_make_pair(BIO *bio1, BIO *bio2)
+	{
+	struct bio_bio_st *b1, *b2;
+
+	assert(bio1 != NULL);
+	assert(bio2 != NULL);
+
+	b1 = bio1->ptr;
+	b2 = bio2->ptr;
+	
+	if (b1->peer != NULL || b2->peer != NULL)
+		{
+		BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
+		return 0;
+		}
+	
+	if (b1->buf != NULL)
+		{
+		b1->buf = Malloc(b1->size);
+		if (b1->buf == NULL)
+			{
+			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
+			return 0;
+			}
+		b1->len = 0;
+		b1->offset = 0;
+		}
+	
+	if (b2->buf != NULL)
+		{
+		b2->buf = Malloc(b2->size);
+		if (b2->buf == NULL)
+			{
+			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
+			return 0;
+			}
+		b2->len = 0;
+		b2->offset = 0;
+		}
+	
+	b1->peer = bio2;
+	b2->peer = bio1;
+
+	return 1;
+	}
+
+static void bio_destroy_pair(BIO *bio)
+	{
+	struct bio_bio_st *b = bio->ptr;
+
+	if (b != NULL)
+		{
+		BIO *peer_bio = b->peer;
+
+		if (peer_bio != NULL)
+			{
+			struct bio_bio_st *peer_b = peer_bio->ptr;
+
+			assert(peer_b != NULL);
+			assert(peer_b->peer == bio);
+
+			peer_b->peer = NULL;
+			peer_bio->init = 0;
+			assert(peer_b->buf != NULL);
+			peer_b->len = 0;
+			peer_b->offset = 0;
+			
+			b->peer = NULL;
+			bio->init = 0;
+			assert(b->buf != NULL);
+			b->len = 0;
+			b->offset = 0;
+			}
+		}
+	}