/* crypto/bio/bss_bio.c -*- Mode: C; c-file-style: "eay" -*- */ /* Special method for a BIO where the other endpoint is also a BIO * of this kind, handled by the same thread (i.e. the "peer" is actually * ourselves, wearing a different hat). * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces * for which no specific BIO method is available. * See ssl/ssltest.c for some hints on how this can be used. */ #ifndef BIO_PAIR_DEBUG # undef NDEBUG /* avoid conflicting definitions */ # define NDEBUG #endif #include #include #include #include #include #include #include #include #include "openssl/e_os.h" #ifndef SSIZE_MAX # define SSIZE_MAX INT_MAX #endif 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, const char *buf, int num); static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr); static int bio_puts(BIO *bio, const 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, NULL /* no bio_callback_ctrl */ }; 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. * peer != NULL iff init != 0 in the BIO. */ /* 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) */ size_t request; /* valid iff peer != NULL; 0 if len != 0, * otherwise set by peer to number of bytes * it (unsuccessfully) tried to read, * never more than buffer space (size-len) warrants. */ }; static int bio_new(BIO *bio) { struct bio_bio_st *b; b = OPENSSL_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; bio->ptr = b; 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) { OPENSSL_free(b->buf); } OPENSSL_free(b); return 1; } static int bio_read(BIO *bio, char *buf, int size_) { size_t size = size_; size_t rest; struct bio_bio_st *b, *peer_b; BIO_clear_retry_flags(bio); if (!bio->init) return 0; b = bio->ptr; assert(b != NULL); assert(b->peer != NULL); peer_b = b->peer->ptr; assert(peer_b != NULL); assert(peer_b->buf != NULL); peer_b->request = 0; /* will be set in "retry_read" situation */ if (buf == NULL || size == 0) return 0; if (peer_b->len == 0) { if (peer_b->closed) return 0; /* writer has closed, and no data is left */ else { BIO_set_retry_read(bio); /* buffer is empty */ if (size <= peer_b->size) peer_b->request = size; else /* don't ask for more than the peer can * deliver in one write */ peer_b->request = peer_b->size; return -1; } } /* we can read */ if (peer_b->len < size) size = peer_b->len; /* now read "size" bytes */ rest = size; assert(rest > 0); do /* one or two iterations */ { size_t chunk; assert(rest <= peer_b->len); if (peer_b->offset + rest <= peer_b->size) chunk = rest; else /* wrap around ring buffer */ chunk = peer_b->size - peer_b->offset; assert(peer_b->offset + chunk <= peer_b->size); memcpy(buf, peer_b->buf + peer_b->offset, chunk); peer_b->len -= chunk; if (peer_b->len) { peer_b->offset += chunk; assert(peer_b->offset <= peer_b->size); if (peer_b->offset == peer_b->size) peer_b->offset = 0; buf += chunk; } else { /* buffer now empty, no need to advance "buf" */ assert(chunk == rest); peer_b->offset = 0; } rest -= chunk; } while (rest); return size; } /* non-copying interface: provide pointer to available data in buffer * bio_nread0: return number of available bytes * bio_nread: also advance index * (example usage: bio_nread0(), read from buffer, bio_nread() * or just bio_nread(), read from buffer) */ /* WARNING: The non-copying interface is largely untested as of yet * and may contain bugs. */ static ssize_t bio_nread0(BIO *bio, char **buf) { struct bio_bio_st *b, *peer_b; ssize_t num; BIO_clear_retry_flags(bio); if (!bio->init) return 0; b = bio->ptr; assert(b != NULL); assert(b->peer != NULL); peer_b = b->peer->ptr; assert(peer_b != NULL); assert(peer_b->buf != NULL); peer_b->request = 0; if (peer_b->len == 0) { char dummy; /* avoid code duplication -- nothing available for reading */ return bio_read(bio, &dummy, 1); /* returns 0 or -1 */ } num = peer_b->len; if (peer_b->size < peer_b->offset + num) /* no ring buffer wrap-around for non-copying interface */ num = peer_b->size - peer_b->offset; assert(num > 0); if (buf != NULL) *buf = peer_b->buf + peer_b->offset; return num; } static ssize_t bio_nread(BIO *bio, char **buf, size_t num_) { struct bio_bio_st *b, *peer_b; ssize_t num, available; if (num_ > SSIZE_MAX) num = SSIZE_MAX; else num = (ssize_t)num_; available = bio_nread0(bio, buf); if (num > available) num = available; if (num <= 0) return num; b = bio->ptr; peer_b = b->peer->ptr; peer_b->len -= num; if (peer_b->len) { peer_b->offset += num; assert(peer_b->offset <= peer_b->size); if (peer_b->offset == peer_b->size) peer_b->offset = 0; } else peer_b->offset = 0; return num; } static int bio_write(BIO *bio, const char *buf, int num_) { size_t num = num_; size_t rest; struct bio_bio_st *b; BIO_clear_retry_flags(bio); if (!bio->init || buf == NULL || num == 0) return 0; b = bio->ptr; assert(b != NULL); assert(b->peer != NULL); assert(b->buf != NULL); b->request = 0; if (b->closed) { /* we already closed */ BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE); return -1; } assert(b->len <= b->size); if (b->len == b->size) { BIO_set_retry_write(bio); /* buffer is full */ return -1; } /* we can write */ if (num > b->size - b->len) num = b->size - b->len; /* now write "num" bytes */ rest = num; assert(rest > 0); do /* one or two iterations */ { size_t write_offset; size_t chunk; assert(b->len + rest <= b->size); write_offset = b->offset + b->len; if (write_offset >= b->size) write_offset -= b->size; /* b->buf[write_offset] is the first byte we can write to. */ if (write_offset + rest <= b->size) chunk = rest; else /* wrap around ring buffer */ chunk = b->size - write_offset; memcpy(b->buf + write_offset, buf, chunk); b->len += chunk; assert(b->len <= b->size); rest -= chunk; buf += chunk; } while (rest); return num; } /* non-copying interface: provide pointer to region to write to * bio_nwrite0: check how much space is available * bio_nwrite: also increase length * (example usage: bio_nwrite0(), write to buffer, bio_nwrite() * or just bio_nwrite(), write to buffer) */ static ssize_t bio_nwrite0(BIO *bio, char **buf) { struct bio_bio_st *b; size_t num; size_t write_offset; BIO_clear_retry_flags(bio); if (!bio->init) return 0; b = bio->ptr; assert(b != NULL); assert(b->peer != NULL); assert(b->buf != NULL); b->request = 0; if (b->closed) { BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE); return -1; } assert(b->len <= b->size); if (b->len == b->size) { BIO_set_retry_write(bio); return -1; } num = b->size - b->len; write_offset = b->offset + b->len; if (write_offset >= b->size) write_offset -= b->size; if (write_offset + num > b->size) /* no ring buffer wrap-around for non-copying interface * (to fulfil the promise by BIO_ctrl_get_write_guarantee, * BIO_nwrite may have to be called twice) */ num = b->size - write_offset; if (buf != NULL) *buf = b->buf + write_offset; assert(write_offset + num <= b->size); return num; } static ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_) { struct bio_bio_st *b; ssize_t num, space; if (num_ > SSIZE_MAX) num = SSIZE_MAX; else num = (ssize_t)num_; space = bio_nwrite0(bio, buf); if (num > space) num = space; if (num <= 0) return num; b = bio->ptr; assert(b != NULL); b->len += num; assert(b->len <= b->size); return num; } static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr) { long ret; struct bio_bio_st *b = bio->ptr; assert(b != NULL); switch (cmd) { /* specific CTRL codes */ case BIO_C_SET_WRITE_BUF_SIZE: if (b->peer) { BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE); ret = 0; } else if (num == 0) { BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT); ret = 0; } else { size_t new_size = num; if (b->size != new_size) { if (b->buf) { OPENSSL_free(b->buf); b->buf = NULL; } b->size = new_size; } ret = 1; } break; case BIO_C_GET_WRITE_BUF_SIZE: num = (long) b->size; case BIO_C_MAKE_BIO_PAIR: { BIO *other_bio = ptr; if (bio_make_pair(bio, other_bio)) ret = 1; else ret = 0; } break; case BIO_C_DESTROY_BIO_PAIR: /* Effects both BIOs in the pair -- call just once! * Or let BIO_free(bio1); BIO_free(bio2); do the job. */ bio_destroy_pair(bio); ret = 1; break; case BIO_C_GET_WRITE_GUARANTEE: /* How many bytes can the caller feed to the next write * without having to keep any? */ if (b->peer == NULL || b->closed) ret = 0; else ret = (long) b->size - b->len; break; case BIO_C_GET_READ_REQUEST: /* If the peer unsuccessfully tried to read, how many bytes * were requested? (As with BIO_CTRL_PENDING, that number * can usually be treated as boolean.) */ ret = (long) b->request; break; case BIO_C_RESET_READ_REQUEST: /* Reset request. (Can be useful after read attempts * at the other side that are meant to be non-blocking, * e.g. when probing SSL_read to see if any data is * available.) */ b->request = 0; ret = 1; break; case BIO_C_SHUTDOWN_WR: /* similar to shutdown(..., SHUT_WR) */ b->closed = 1; ret = 1; break; case BIO_C_NREAD0: /* prepare for non-copying read */ ret = (long) bio_nread0(bio, ptr); break; case BIO_C_NREAD: /* non-copying read */ ret = (long) bio_nread(bio, ptr, (size_t) num); break; case BIO_C_NWRITE0: /* prepare for non-copying write */ ret = (long) bio_nwrite0(bio, ptr); break; case BIO_C_NWRITE: /* non-copying write */ ret = (long) bio_nwrite(bio, ptr, (size_t) num); break; /* standard CTRL codes follow */ 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: /* See BIO_dup_chain for circumstances we have to expect. */ { BIO *other_bio = ptr; struct bio_bio_st *other_b; assert(other_bio != NULL); other_b = other_bio->ptr; assert(other_b != NULL); assert(other_b->buf == NULL); /* other_bio is always fresh */ other_b->size = b->size; } ret = 1; break; case BIO_CTRL_FLUSH: ret = 1; break; case BIO_CTRL_EOF: { BIO *other_bio = ptr; if (other_bio) { struct bio_bio_st *other_b = other_bio->ptr; assert(other_b != NULL); ret = other_b->len == 0 && other_b->closed; } else ret = 1; } break; default: ret = 0; } return ret; } static int bio_puts(BIO *bio, const 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 = OPENSSL_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 = OPENSSL_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; b1->closed = 0; b1->request = 0; b2->peer = bio1; b2->closed = 0; b2->request = 0; bio1->init = 1; bio2->init = 1; 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; } } } /* Exported convenience functions */ int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1, BIO **bio2_p, size_t writebuf2) { BIO *bio1 = NULL, *bio2 = NULL; long r; int ret = 0; bio1 = BIO_new(BIO_s_bio()); if (bio1 == NULL) goto err; bio2 = BIO_new(BIO_s_bio()); if (bio2 == NULL) goto err; if (writebuf1) { r = BIO_set_write_buf_size(bio1, writebuf1); if (!r) goto err; } if (writebuf2) { r = BIO_set_write_buf_size(bio2, writebuf2); if (!r) goto err; } r = BIO_make_bio_pair(bio1, bio2); if (!r) goto err; ret = 1; err: if (ret == 0) { if (bio1) { BIO_free(bio1); bio1 = NULL; } if (bio2) { BIO_free(bio2); bio2 = NULL; } } *bio1_p = bio1; *bio2_p = bio2; return ret; } size_t BIO_ctrl_get_write_guarantee(BIO *bio) { return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL); } size_t BIO_ctrl_get_read_request(BIO *bio) { return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL); } int BIO_ctrl_reset_read_request(BIO *bio) { return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0); } /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now * (conceivably some other BIOs could allow non-copying reads and writes too.) */ int BIO_nread0(BIO *bio, char **buf) { long ret; if (!bio->init) { BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED); return -2; } ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf); if (ret > INT_MAX) return INT_MAX; else return (int) ret; } int BIO_nread(BIO *bio, char **buf, int num) { int ret; if (!bio->init) { BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED); return -2; } ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf); if (ret > 0) bio->num_read += ret; return ret; } int BIO_nwrite0(BIO *bio, char **buf) { long ret; if (!bio->init) { BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED); return -2; } ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf); if (ret > INT_MAX) return INT_MAX; else return (int) ret; } int BIO_nwrite(BIO *bio, char **buf, int num) { int ret; if (!bio->init) { BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED); return -2; } ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf); if (ret > 0) bio->num_read += ret; return ret; }