/* * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include #include #include "bio_local.h" #include "internal/cryptlib.h" #include "internal/safe_math.h" #if !defined(OPENSSL_NO_DGRAM) && !defined(OPENSSL_NO_SOCK) OSSL_SAFE_MATH_UNSIGNED(size_t, size_t) /* =========================================================================== * Byte-wise ring buffer which supports pushing and popping blocks of multiple * bytes at a time. */ struct ring_buf { unsigned char *start; /* start of buffer */ size_t len; /* size of buffer allocation in bytes */ size_t count; /* number of bytes currently pushed */ /* * These index into start. Where idx[0] == idx[1], the buffer is full * (if count is nonzero) and empty otherwise. */ size_t idx[2]; /* 0: head, 1: tail */ }; static int ring_buf_init(struct ring_buf *r, size_t nbytes) { r->start = OPENSSL_malloc(nbytes); if (r->start == NULL) return 0; r->len = nbytes; r->idx[0] = r->idx[1] = r->count = 0; return 1; } static void ring_buf_destroy(struct ring_buf *r) { OPENSSL_free(r->start); r->start = NULL; r->len = 0; r->count = 0; } /* * Get a pointer to the next place to write data to be pushed to the ring buffer * (idx=0), or the next data to be popped from the ring buffer (idx=1). The * pointer is written to *buf and the maximum number of bytes which can be * read/written are written to *len. After writing data to the buffer, call * ring_buf_push/pop() with the number of bytes actually read/written, which * must not exceed the returned length. */ static void ring_buf_head_tail(struct ring_buf *r, int idx, uint8_t **buf, size_t *len) { size_t max_len = r->len - r->idx[idx]; if (idx == 0 && max_len > r->len - r->count) max_len = r->len - r->count; if (idx == 1 && max_len > r->count) max_len = r->count; *buf = (uint8_t *)r->start + r->idx[idx]; *len = max_len; } #define ring_buf_head(r, buf, len) ring_buf_head_tail((r), 0, (buf), (len)) #define ring_buf_tail(r, buf, len) ring_buf_head_tail((r), 1, (buf), (len)) /* * Commit bytes to the ring buffer previously filled after a call to * ring_buf_head(). */ static void ring_buf_push_pop(struct ring_buf *r, int idx, size_t num_bytes) { size_t new_idx; /* A single push/pop op cannot wrap around, though it can reach the end. * If the caller adheres to the convention of using the length returned * by ring_buf_head/tail(), this cannot happen. */ if (!ossl_assert(num_bytes <= r->len - r->idx[idx])) return; /* * Must not overfill the buffer, or pop more than is in the buffer either. */ if (!ossl_assert(idx != 0 ? num_bytes <= r->count : num_bytes + r->count <= r->len)) return; /* Update the index. */ new_idx = r->idx[idx] + num_bytes; if (new_idx == r->len) new_idx = 0; r->idx[idx] = new_idx; if (idx != 0) r->count -= num_bytes; else r->count += num_bytes; } #define ring_buf_push(r, num_bytes) ring_buf_push_pop((r), 0, (num_bytes)) #define ring_buf_pop(r, num_bytes) ring_buf_push_pop((r), 1, (num_bytes)) static void ring_buf_clear(struct ring_buf *r) { r->idx[0] = r->idx[1] = r->count = 0; } static int ring_buf_resize(struct ring_buf *r, size_t nbytes) { unsigned char *new_start; if (r->start == NULL) return ring_buf_init(r, nbytes); if (nbytes == r->len) return 1; if (r->count > 0 && nbytes < r->len) /* fail shrinking the ring buffer when there is any data in it */ return 0; new_start = OPENSSL_realloc(r->start, nbytes); if (new_start == NULL) return 0; /* Moving tail if it is after (or equal to) head */ if (r->count > 0) { if (r->idx[0] <= r->idx[1]) { size_t offset = nbytes - r->len; memmove(new_start + r->idx[1] + offset, new_start + r->idx[1], r->len - r->idx[1]); r->idx[1] += offset; } } else { /* just reset the head/tail because it might be pointing outside */ r->idx[0] = r->idx[1] = 0; } r->start = new_start; r->len = nbytes; return 1; } /* =========================================================================== * BIO_s_dgram_pair is documented in BIO_s_dgram_pair(3). * * INTERNAL DATA STRUCTURE * * This is managed internally by using a bytewise ring buffer which supports * pushing and popping spans of multiple bytes at once. The ring buffer stores * internal packets which look like this: * * struct dgram_hdr hdr; * uint8_t data[]; * * The header contains the length of the data and metadata such as * source/destination addresses. * * The datagram pair BIO is designed to support both traditional * BIO_read/BIO_write (likely to be used by applications) as well as * BIO_recvmmsg/BIO_sendmmsg. */ struct bio_dgram_pair_st; static int dgram_pair_write(BIO *bio, const char *buf, int sz_); static int dgram_pair_read(BIO *bio, char *buf, int sz_); static int dgram_mem_read(BIO *bio, char *buf, int sz_); static long dgram_pair_ctrl(BIO *bio, int cmd, long num, void *ptr); static long dgram_mem_ctrl(BIO *bio, int cmd, long num, void *ptr); static int dgram_pair_init(BIO *bio); static int dgram_mem_init(BIO *bio); static int dgram_pair_free(BIO *bio); static int dgram_pair_sendmmsg(BIO *b, BIO_MSG *msg, size_t stride, size_t num_msg, uint64_t flags, size_t *num_processed); static int dgram_pair_recvmmsg(BIO *b, BIO_MSG *msg, size_t stride, size_t num_msg, uint64_t flags, size_t *num_processed); static int dgram_pair_ctrl_destroy_bio_pair(BIO *bio1); static size_t dgram_pair_read_inner(struct bio_dgram_pair_st *b, uint8_t *buf, size_t sz); #define BIO_MSG_N(array, n) (*(BIO_MSG *)((char *)(array) + (n)*stride)) static const BIO_METHOD dgram_pair_method = { BIO_TYPE_DGRAM_PAIR, "BIO dgram pair", bwrite_conv, dgram_pair_write, bread_conv, dgram_pair_read, NULL, /* dgram_pair_puts */ NULL, /* dgram_pair_gets */ dgram_pair_ctrl, dgram_pair_init, dgram_pair_free, NULL, /* dgram_pair_callback_ctrl */ dgram_pair_sendmmsg, dgram_pair_recvmmsg, }; static const BIO_METHOD dgram_mem_method = { BIO_TYPE_DGRAM_MEM, "BIO dgram mem", bwrite_conv, dgram_pair_write, bread_conv, dgram_mem_read, NULL, /* dgram_pair_puts */ NULL, /* dgram_pair_gets */ dgram_mem_ctrl, dgram_mem_init, dgram_pair_free, NULL, /* dgram_pair_callback_ctrl */ dgram_pair_sendmmsg, dgram_pair_recvmmsg, }; const BIO_METHOD *BIO_s_dgram_pair(void) { return &dgram_pair_method; } const BIO_METHOD *BIO_s_dgram_mem(void) { return &dgram_mem_method; } struct dgram_hdr { size_t len; /* payload length in bytes, not including this struct */ BIO_ADDR src_addr, dst_addr; /* family == 0: not present */ }; struct bio_dgram_pair_st { /* The other half of the BIO pair. NULL for dgram_mem. */ BIO *peer; /* Writes are directed to our own ringbuf and reads to our peer. */ struct ring_buf rbuf; /* Requested size of rbuf buffer in bytes once we initialize. */ size_t req_buf_len; /* Largest possible datagram size */ size_t mtu; /* Capability flags. */ uint32_t cap; /* * This lock protects updates to our rbuf. Since writes are directed to our * own rbuf, this means we use this lock for writes and our peer's lock for * reads. */ CRYPTO_RWLOCK *lock; unsigned int no_trunc : 1; /* Reads fail if they would truncate */ unsigned int local_addr_enable : 1; /* Can use BIO_MSG->local? */ unsigned int role : 1; /* Determines lock order */ unsigned int fixed_size : 1; /* Affects BIO_s_dgram_mem only */ }; #define MIN_BUF_LEN (1024) #define is_dgram_pair(b) (b->peer != NULL) static int dgram_pair_init(BIO *bio) { struct bio_dgram_pair_st *b = OPENSSL_zalloc(sizeof(*b)); if (b == NULL) return 0; b->req_buf_len = 17*1024; /* default buffer size */ b->mtu = 1472; /* conservative default MTU */ b->lock = CRYPTO_THREAD_lock_new(); if (b->lock == NULL) { OPENSSL_free(b); return 0; } bio->ptr = b; return 1; } static int dgram_mem_init(BIO *bio) { struct bio_dgram_pair_st *b; if (!dgram_pair_init(bio)) return 0; b = bio->ptr; if (ring_buf_init(&b->rbuf, b->req_buf_len) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_BIO_LIB); return 0; } bio->init = 1; return 1; } static int dgram_pair_free(BIO *bio) { struct bio_dgram_pair_st *b; if (bio == NULL) return 0; b = bio->ptr; if (!ossl_assert(b != NULL)) return 0; /* We are being freed. Disconnect any peer and destroy buffers. */ dgram_pair_ctrl_destroy_bio_pair(bio); CRYPTO_THREAD_lock_free(b->lock); OPENSSL_free(b); return 1; } /* BIO_make_bio_pair (BIO_C_MAKE_BIO_PAIR) */ static int dgram_pair_ctrl_make_bio_pair(BIO *bio1, BIO *bio2) { struct bio_dgram_pair_st *b1, *b2; /* peer must be non-NULL. */ if (bio1 == NULL || bio2 == NULL) { ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT); return 0; } /* Ensure the BIO we have been passed is actually a dgram pair BIO. */ if (bio1->method != &dgram_pair_method || bio2->method != &dgram_pair_method) { ERR_raise_data(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT, "both BIOs must be BIO_dgram_pair"); return 0; } b1 = bio1->ptr; b2 = bio2->ptr; if (!ossl_assert(b1 != NULL && b2 != NULL)) { ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); return 0; } /* * This ctrl cannot be used to associate a BIO pair half which is already * associated. */ if (b1->peer != NULL || b2->peer != NULL) { ERR_raise_data(ERR_LIB_BIO, BIO_R_IN_USE, "cannot associate a BIO_dgram_pair which is already in use"); return 0; } if (!ossl_assert(b1->req_buf_len >= MIN_BUF_LEN && b2->req_buf_len >= MIN_BUF_LEN)) { ERR_raise(ERR_LIB_BIO, BIO_R_UNINITIALIZED); return 0; } if (b1->rbuf.len != b1->req_buf_len) if (ring_buf_init(&b1->rbuf, b1->req_buf_len) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_BIO_LIB); return 0; } if (b2->rbuf.len != b2->req_buf_len) if (ring_buf_init(&b2->rbuf, b2->req_buf_len) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_BIO_LIB); ring_buf_destroy(&b1->rbuf); return 0; } b1->peer = bio2; b2->peer = bio1; b1->role = 0; b2->role = 1; bio1->init = 1; bio2->init = 1; return 1; } /* BIO_destroy_bio_pair (BIO_C_DESTROY_BIO_PAIR) */ static int dgram_pair_ctrl_destroy_bio_pair(BIO *bio1) { BIO *bio2; struct bio_dgram_pair_st *b1 = bio1->ptr, *b2; ring_buf_destroy(&b1->rbuf); bio1->init = 0; /* Early return if we don't have a peer. */ if (b1->peer == NULL) return 1; bio2 = b1->peer; b2 = bio2->ptr; /* Invariant. */ if (!ossl_assert(b2->peer == bio1)) return 0; /* Free buffers. */ ring_buf_destroy(&b2->rbuf); bio2->init = 0; b1->peer = NULL; b2->peer = NULL; return 1; } /* BIO_eof (BIO_CTRL_EOF) */ static int dgram_pair_ctrl_eof(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr, *peerb; if (!ossl_assert(b != NULL)) return -1; /* If we aren't initialized, we can never read anything */ if (!bio->init) return 1; if (!is_dgram_pair(b)) return 0; peerb = b->peer->ptr; if (!ossl_assert(peerb != NULL)) return -1; /* * Since we are emulating datagram semantics, never indicate EOF so long as * we have a peer. */ return 0; } /* BIO_set_write_buf_size (BIO_C_SET_WRITE_BUF_SIZE) */ static int dgram_pair_ctrl_set_write_buf_size(BIO *bio, size_t len) { struct bio_dgram_pair_st *b = bio->ptr; /* Changing buffer sizes is not permitted while a peer is connected. */ if (b->peer != NULL) { ERR_raise(ERR_LIB_BIO, BIO_R_IN_USE); return 0; } /* Enforce minimum size. */ if (len < MIN_BUF_LEN) len = MIN_BUF_LEN; if (b->rbuf.start != NULL) { if (!ring_buf_resize(&b->rbuf, len)) return 0; } b->req_buf_len = len; b->fixed_size = 1; return 1; } /* BIO_reset (BIO_CTRL_RESET) */ static int dgram_pair_ctrl_reset(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr; ring_buf_clear(&b->rbuf); return 1; } /* BIO_pending (BIO_CTRL_PENDING) (Threadsafe) */ static size_t dgram_pair_ctrl_pending(BIO *bio) { size_t saved_idx, saved_count; struct bio_dgram_pair_st *b = bio->ptr, *readb; struct dgram_hdr hdr; size_t l; /* Safe to check; init may not change during this call */ if (!bio->init) return 0; if (is_dgram_pair(b)) readb = b->peer->ptr; else readb = b; if (CRYPTO_THREAD_write_lock(readb->lock) == 0) return 0; saved_idx = readb->rbuf.idx[1]; saved_count = readb->rbuf.count; l = dgram_pair_read_inner(readb, (uint8_t *)&hdr, sizeof(hdr)); readb->rbuf.idx[1] = saved_idx; readb->rbuf.count = saved_count; CRYPTO_THREAD_unlock(readb->lock); if (!ossl_assert(l == 0 || l == sizeof(hdr))) return 0; return l > 0 ? hdr.len : 0; } /* BIO_get_write_guarantee (BIO_C_GET_WRITE_GUARANTEE) (Threadsafe) */ static size_t dgram_pair_ctrl_get_write_guarantee(BIO *bio) { size_t l; struct bio_dgram_pair_st *b = bio->ptr; if (CRYPTO_THREAD_read_lock(b->lock) == 0) return 0; l = b->rbuf.len - b->rbuf.count; if (l >= sizeof(struct dgram_hdr)) l -= sizeof(struct dgram_hdr); /* * If the amount of buffer space would not be enough to accommodate the * worst-case size of a datagram, report no space available. */ if (l < b->mtu) l = 0; CRYPTO_THREAD_unlock(b->lock); return l; } /* BIO_dgram_get_local_addr_cap (BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP) */ static int dgram_pair_ctrl_get_local_addr_cap(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr, *readb; if (!bio->init) return 0; if (is_dgram_pair(b)) readb = b->peer->ptr; else readb = b; return (~readb->cap & (BIO_DGRAM_CAP_HANDLES_SRC_ADDR | BIO_DGRAM_CAP_PROVIDES_DST_ADDR)) == 0; } /* BIO_dgram_get_effective_caps (BIO_CTRL_DGRAM_GET_EFFECTIVE_CAPS) */ static int dgram_pair_ctrl_get_effective_caps(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr, *peerb; if (b->peer == NULL) return 0; peerb = b->peer->ptr; return peerb->cap; } /* BIO_dgram_get_caps (BIO_CTRL_DGRAM_GET_CAPS) */ static uint32_t dgram_pair_ctrl_get_caps(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr; return b->cap; } /* BIO_dgram_set_caps (BIO_CTRL_DGRAM_SET_CAPS) */ static int dgram_pair_ctrl_set_caps(BIO *bio, uint32_t caps) { struct bio_dgram_pair_st *b = bio->ptr; b->cap = caps; return 1; } /* BIO_dgram_get_local_addr_enable (BIO_CTRL_DGRAM_GET_LOCAL_ADDR_ENABLE) */ static int dgram_pair_ctrl_get_local_addr_enable(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr; return b->local_addr_enable; } /* BIO_dgram_set_local_addr_enable (BIO_CTRL_DGRAM_SET_LOCAL_ADDR_ENABLE) */ static int dgram_pair_ctrl_set_local_addr_enable(BIO *bio, int enable) { struct bio_dgram_pair_st *b = bio->ptr; if (dgram_pair_ctrl_get_local_addr_cap(bio) == 0) return 0; b->local_addr_enable = (enable != 0 ? 1 : 0); return 1; } /* BIO_dgram_get_mtu (BIO_CTRL_DGRAM_GET_MTU) */ static int dgram_pair_ctrl_get_mtu(BIO *bio) { struct bio_dgram_pair_st *b = bio->ptr; return b->mtu; } /* BIO_dgram_set_mtu (BIO_CTRL_DGRAM_SET_MTU) */ static int dgram_pair_ctrl_set_mtu(BIO *bio, size_t mtu) { struct bio_dgram_pair_st *b = bio->ptr, *peerb; b->mtu = mtu; if (b->peer != NULL) { peerb = b->peer->ptr; peerb->mtu = mtu; } return 1; } /* Partially threadsafe (some commands) */ static long dgram_mem_ctrl(BIO *bio, int cmd, long num, void *ptr) { long ret = 1; struct bio_dgram_pair_st *b = bio->ptr; if (!ossl_assert(b != NULL)) return 0; switch (cmd) { /* * BIO_set_write_buf_size: Set the size of the ring buffer used for storing * datagrams. No more writes can be performed once the buffer is filled up, * until reads are performed. This cannot be used after a peer is connected. */ case BIO_C_SET_WRITE_BUF_SIZE: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_set_write_buf_size(bio, (size_t)num); break; /* * BIO_get_write_buf_size: Get ring buffer size. */ case BIO_C_GET_WRITE_BUF_SIZE: /* Non-threadsafe */ ret = (long)b->req_buf_len; break; /* * BIO_reset: Clear all data which was written to this side of the pair. */ case BIO_CTRL_RESET: /* Non-threadsafe */ dgram_pair_ctrl_reset(bio); break; /* * BIO_get_write_guarantee: Any BIO_write providing a buffer less than or * equal to this value is guaranteed to succeed. */ case BIO_C_GET_WRITE_GUARANTEE: /* Threadsafe */ ret = (long)dgram_pair_ctrl_get_write_guarantee(bio); break; /* BIO_pending: Bytes available to read. */ case BIO_CTRL_PENDING: /* Threadsafe */ ret = (long)dgram_pair_ctrl_pending(bio); break; /* BIO_flush: No-op. */ case BIO_CTRL_FLUSH: /* Threadsafe */ break; /* BIO_dgram_get_no_trunc */ case BIO_CTRL_DGRAM_GET_NO_TRUNC: /* Non-threadsafe */ ret = (long)b->no_trunc; break; /* BIO_dgram_set_no_trunc */ case BIO_CTRL_DGRAM_SET_NO_TRUNC: /* Non-threadsafe */ b->no_trunc = (num > 0); break; /* BIO_dgram_get_local_addr_enable */ case BIO_CTRL_DGRAM_GET_LOCAL_ADDR_ENABLE: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_get_local_addr_enable(bio); break; /* BIO_dgram_set_local_addr_enable */ case BIO_CTRL_DGRAM_SET_LOCAL_ADDR_ENABLE: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_set_local_addr_enable(bio, num); break; /* BIO_dgram_get_local_addr_cap: Can local addresses be supported? */ case BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_get_local_addr_cap(bio); break; /* BIO_dgram_get_effective_caps */ case BIO_CTRL_DGRAM_GET_EFFECTIVE_CAPS: /* Non-threadsafe */ /* BIO_dgram_get_caps */ case BIO_CTRL_DGRAM_GET_CAPS: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_get_caps(bio); break; /* BIO_dgram_set_caps */ case BIO_CTRL_DGRAM_SET_CAPS: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_set_caps(bio, (uint32_t)num); break; /* BIO_dgram_get_mtu */ case BIO_CTRL_DGRAM_GET_MTU: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_get_mtu(bio); break; /* BIO_dgram_set_mtu */ case BIO_CTRL_DGRAM_SET_MTU: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_set_mtu(bio, (uint32_t)num); break; /* * BIO_eof: Returns whether this half of the BIO pair is empty of data to * read. */ case BIO_CTRL_EOF: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_eof(bio); break; default: ret = 0; break; } return ret; } static long dgram_pair_ctrl(BIO *bio, int cmd, long num, void *ptr) { long ret = 1; switch (cmd) { /* * BIO_make_bio_pair: this is usually used by BIO_new_dgram_pair, though it * may be used manually after manually creating each half of a BIO pair * using BIO_new. This only needs to be called on one of the BIOs. */ case BIO_C_MAKE_BIO_PAIR: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_make_bio_pair(bio, (BIO *)ptr); break; /* * BIO_destroy_bio_pair: Manually disconnect two halves of a BIO pair so * that they are no longer peers. */ case BIO_C_DESTROY_BIO_PAIR: /* Non-threadsafe */ dgram_pair_ctrl_destroy_bio_pair(bio); break; /* BIO_dgram_get_effective_caps */ case BIO_CTRL_DGRAM_GET_EFFECTIVE_CAPS: /* Non-threadsafe */ ret = (long)dgram_pair_ctrl_get_effective_caps(bio); break; default: ret = dgram_mem_ctrl(bio, cmd, num, ptr); break; } return ret; } int BIO_new_bio_dgram_pair(BIO **pbio1, size_t writebuf1, BIO **pbio2, size_t writebuf2) { int ret = 0; long r; BIO *bio1 = NULL, *bio2 = NULL; bio1 = BIO_new(BIO_s_dgram_pair()); if (bio1 == NULL) goto err; bio2 = BIO_new(BIO_s_dgram_pair()); if (bio2 == NULL) goto err; if (writebuf1 > 0) { r = BIO_set_write_buf_size(bio1, writebuf1); if (r == 0) goto err; } if (writebuf2 > 0) { r = BIO_set_write_buf_size(bio2, writebuf2); if (r == 0) goto err; } r = BIO_make_bio_pair(bio1, bio2); if (r == 0) goto err; ret = 1; err: if (ret == 0) { BIO_free(bio1); bio1 = NULL; BIO_free(bio2); bio2 = NULL; } *pbio1 = bio1; *pbio2 = bio2; return ret; } /* Must hold peer write lock */ static size_t dgram_pair_read_inner(struct bio_dgram_pair_st *b, uint8_t *buf, size_t sz) { size_t total_read = 0; /* * We repeat pops from the ring buffer for as long as we have more * application *buffer to fill until we fail. We may not be able to pop * enough data to fill the buffer in one operation if the ring buffer wraps * around, but there may still be more data available. */ while (sz > 0) { uint8_t *src_buf = NULL; size_t src_len = 0; /* * There are two BIO instances, each with a ringbuf. We read from the * peer ringbuf and write to our own ringbuf. */ ring_buf_tail(&b->rbuf, &src_buf, &src_len); if (src_len == 0) break; if (src_len > sz) src_len = sz; if (buf != NULL) memcpy(buf, src_buf, src_len); ring_buf_pop(&b->rbuf, src_len); if (buf != NULL) buf += src_len; total_read += src_len; sz -= src_len; } return total_read; } /* * Must hold peer write lock. Returns number of bytes processed or negated BIO * response code. */ static ossl_ssize_t dgram_pair_read_actual(BIO *bio, char *buf, size_t sz, BIO_ADDR *local, BIO_ADDR *peer, int is_multi) { size_t l, trunc = 0, saved_idx, saved_count; struct bio_dgram_pair_st *b = bio->ptr, *readb; struct dgram_hdr hdr; if (!is_multi) BIO_clear_retry_flags(bio); if (!bio->init) return -BIO_R_UNINITIALIZED; if (!ossl_assert(b != NULL)) return -BIO_R_TRANSFER_ERROR; if (is_dgram_pair(b)) readb = b->peer->ptr; else readb = b; if (!ossl_assert(readb != NULL && readb->rbuf.start != NULL)) return -BIO_R_TRANSFER_ERROR; if (sz > 0 && buf == NULL) return -BIO_R_INVALID_ARGUMENT; /* If the caller wants to know the local address, it must be enabled */ if (local != NULL && b->local_addr_enable == 0) return -BIO_R_LOCAL_ADDR_NOT_AVAILABLE; /* Read the header. */ saved_idx = readb->rbuf.idx[1]; saved_count = readb->rbuf.count; l = dgram_pair_read_inner(readb, (uint8_t *)&hdr, sizeof(hdr)); if (l == 0) { /* Buffer was empty. */ if (!is_multi) BIO_set_retry_read(bio); return -BIO_R_NON_FATAL; } if (!ossl_assert(l == sizeof(hdr))) /* * This should not be possible as headers (and their following payloads) * should always be written atomically. */ return -BIO_R_BROKEN_PIPE; if (sz > hdr.len) { sz = hdr.len; } else if (sz < hdr.len) { /* Truncation is occurring. */ trunc = hdr.len - sz; if (b->no_trunc) { /* Restore original state. */ readb->rbuf.idx[1] = saved_idx; readb->rbuf.count = saved_count; return -BIO_R_NON_FATAL; } } l = dgram_pair_read_inner(readb, (uint8_t *)buf, sz); if (!ossl_assert(l == sz)) /* We were somehow not able to read the entire datagram. */ return -BIO_R_TRANSFER_ERROR; /* * If the datagram was truncated due to an inadequate buffer, discard the * remainder. */ if (trunc > 0 && !ossl_assert(dgram_pair_read_inner(readb, NULL, trunc) == trunc)) /* We were somehow not able to read/skip the entire datagram. */ return -BIO_R_TRANSFER_ERROR; if (local != NULL) *local = hdr.dst_addr; if (peer != NULL) *peer = hdr.src_addr; return (ossl_ssize_t)l; } /* Threadsafe */ static int dgram_pair_lock_both_write(struct bio_dgram_pair_st *a, struct bio_dgram_pair_st *b) { struct bio_dgram_pair_st *x, *y; x = (a->role == 1) ? a : b; y = (a->role == 1) ? b : a; if (!ossl_assert(a->role != b->role)) return 0; if (!ossl_assert(a != b && x != y)) return 0; if (CRYPTO_THREAD_write_lock(x->lock) == 0) return 0; if (CRYPTO_THREAD_write_lock(y->lock) == 0) { CRYPTO_THREAD_unlock(x->lock); return 0; } return 1; } static void dgram_pair_unlock_both(struct bio_dgram_pair_st *a, struct bio_dgram_pair_st *b) { CRYPTO_THREAD_unlock(a->lock); CRYPTO_THREAD_unlock(b->lock); } /* Threadsafe */ static int dgram_pair_read(BIO *bio, char *buf, int sz_) { int ret; ossl_ssize_t l; struct bio_dgram_pair_st *b = bio->ptr, *peerb; if (sz_ < 0) { ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT); return -1; } if (b->peer == NULL) { ERR_raise(ERR_LIB_BIO, BIO_R_BROKEN_PIPE); return -1; } peerb = b->peer->ptr; /* * For BIO_read we have to acquire both locks because we touch the retry * flags on the local bio. (This is avoided in the recvmmsg case as it does * not touch the retry flags.) */ if (dgram_pair_lock_both_write(peerb, b) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_UNABLE_TO_GET_WRITE_LOCK); return -1; } l = dgram_pair_read_actual(bio, buf, (size_t)sz_, NULL, NULL, 0); if (l < 0) { if (l != -BIO_R_NON_FATAL) ERR_raise(ERR_LIB_BIO, -l); ret = -1; } else { ret = (int)l; } dgram_pair_unlock_both(peerb, b); return ret; } /* Threadsafe */ static int dgram_pair_recvmmsg(BIO *bio, BIO_MSG *msg, size_t stride, size_t num_msg, uint64_t flags, size_t *num_processed) { int ret; ossl_ssize_t l; BIO_MSG *m; size_t i; struct bio_dgram_pair_st *b = bio->ptr, *readb; if (num_msg == 0) { *num_processed = 0; return 1; } if (!bio->init) { ERR_raise(ERR_LIB_BIO, BIO_R_BROKEN_PIPE); *num_processed = 0; return 0; } if (is_dgram_pair(b)) readb = b->peer->ptr; else readb = b; if (CRYPTO_THREAD_write_lock(readb->lock) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_UNABLE_TO_GET_WRITE_LOCK); *num_processed = 0; return 0; } for (i = 0; i < num_msg; ++i) { m = &BIO_MSG_N(msg, i); l = dgram_pair_read_actual(bio, m->data, m->data_len, m->local, m->peer, 1); if (l < 0) { *num_processed = i; if (i > 0) { ret = 1; } else { ERR_raise(ERR_LIB_BIO, -l); ret = 0; } goto out; } m->data_len = l; m->flags = 0; } *num_processed = i; ret = 1; out: CRYPTO_THREAD_unlock(readb->lock); return ret; } /* Threadsafe */ static int dgram_mem_read(BIO *bio, char *buf, int sz_) { int ret; ossl_ssize_t l; struct bio_dgram_pair_st *b = bio->ptr; if (sz_ < 0) { ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT); return -1; } if (CRYPTO_THREAD_write_lock(b->lock) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_UNABLE_TO_GET_WRITE_LOCK); return -1; } l = dgram_pair_read_actual(bio, buf, (size_t)sz_, NULL, NULL, 0); if (l < 0) { if (l != -BIO_R_NON_FATAL) ERR_raise(ERR_LIB_BIO, -l); ret = -1; } else { ret = (int)l; } CRYPTO_THREAD_unlock(b->lock); return ret; } /* * Calculate the array growth based on the target size. * * The growth factor is a rational number and is defined by a numerator * and a denominator. According to Andrew Koenig in his paper "Why Are * Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less * than the golden ratio (1.618...). * * We use an expansion factor of 8 / 5 = 1.6 */ static const size_t max_rbuf_size = SIZE_MAX / 2; /* unlimited in practice */ static ossl_inline size_t compute_rbuf_growth(size_t target, size_t current) { int err = 0; while (current < target) { if (current >= max_rbuf_size) return 0; current = safe_muldiv_size_t(current, 8, 5, &err); if (err) return 0; if (current >= max_rbuf_size) current = max_rbuf_size; } return current; } /* Must hold local write lock */ static size_t dgram_pair_write_inner(struct bio_dgram_pair_st *b, const uint8_t *buf, size_t sz) { size_t total_written = 0; /* * We repeat pushes to the ring buffer for as long as we have data until we * fail. We may not be able to push in one operation if the ring buffer * wraps around, but there may still be more room for data. */ while (sz > 0) { size_t dst_len; uint8_t *dst_buf; /* * There are two BIO instances, each with a ringbuf. We write to our own * ringbuf and read from the peer ringbuf. */ ring_buf_head(&b->rbuf, &dst_buf, &dst_len); if (dst_len == 0) { size_t new_len; if (!b->fixed_size) /* resizeable only unless size not set explicitly */ break; /* increase the size */ new_len = compute_rbuf_growth(b->req_buf_len + sz, b->req_buf_len); if (new_len == 0 || !ring_buf_resize(&b->rbuf, new_len)) break; b->req_buf_len = new_len; } if (dst_len > sz) dst_len = sz; memcpy(dst_buf, buf, dst_len); ring_buf_push(&b->rbuf, dst_len); buf += dst_len; sz -= dst_len; total_written += dst_len; } return total_written; } /* * Must hold local write lock. Returns number of bytes processed or negated BIO * response code. */ static ossl_ssize_t dgram_pair_write_actual(BIO *bio, const char *buf, size_t sz, const BIO_ADDR *local, const BIO_ADDR *peer, int is_multi) { static const BIO_ADDR zero_addr; size_t saved_idx, saved_count; struct bio_dgram_pair_st *b = bio->ptr, *readb; struct dgram_hdr hdr = {0}; if (!is_multi) BIO_clear_retry_flags(bio); if (!bio->init) return -BIO_R_UNINITIALIZED; if (!ossl_assert(b != NULL && b->rbuf.start != NULL)) return -BIO_R_TRANSFER_ERROR; if (sz > 0 && buf == NULL) return -BIO_R_INVALID_ARGUMENT; if (local != NULL && b->local_addr_enable == 0) return -BIO_R_LOCAL_ADDR_NOT_AVAILABLE; if (is_dgram_pair(b)) readb = b->peer->ptr; else readb = b; if (peer != NULL && (readb->cap & BIO_DGRAM_CAP_HANDLES_DST_ADDR) == 0) return -BIO_R_PEER_ADDR_NOT_AVAILABLE; hdr.len = sz; hdr.dst_addr = (peer != NULL ? *peer : zero_addr); hdr.src_addr = (local != NULL ? *local : zero_addr); saved_idx = b->rbuf.idx[0]; saved_count = b->rbuf.count; if (dgram_pair_write_inner(b, (const uint8_t *)&hdr, sizeof(hdr)) != sizeof(hdr) || dgram_pair_write_inner(b, (const uint8_t *)buf, sz) != sz) { /* * We were not able to push the header and the entirety of the payload * onto the ring buffer, so abort and roll back the ring buffer state. */ b->rbuf.idx[0] = saved_idx; b->rbuf.count = saved_count; if (!is_multi) BIO_set_retry_write(bio); return -BIO_R_NON_FATAL; } return sz; } /* Threadsafe */ static int dgram_pair_write(BIO *bio, const char *buf, int sz_) { int ret; ossl_ssize_t l; struct bio_dgram_pair_st *b = bio->ptr; if (sz_ < 0) { ERR_raise(ERR_LIB_BIO, BIO_R_INVALID_ARGUMENT); return -1; } if (CRYPTO_THREAD_write_lock(b->lock) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_UNABLE_TO_GET_WRITE_LOCK); return -1; } l = dgram_pair_write_actual(bio, buf, (size_t)sz_, NULL, NULL, 0); if (l < 0) { ERR_raise(ERR_LIB_BIO, -l); ret = -1; } else { ret = (int)l; } CRYPTO_THREAD_unlock(b->lock); return ret; } /* Threadsafe */ static int dgram_pair_sendmmsg(BIO *bio, BIO_MSG *msg, size_t stride, size_t num_msg, uint64_t flags, size_t *num_processed) { ossl_ssize_t ret, l; BIO_MSG *m; size_t i; struct bio_dgram_pair_st *b = bio->ptr; if (num_msg == 0) { *num_processed = 0; return 1; } if (CRYPTO_THREAD_write_lock(b->lock) == 0) { ERR_raise(ERR_LIB_BIO, ERR_R_UNABLE_TO_GET_WRITE_LOCK); *num_processed = 0; return 0; } for (i = 0; i < num_msg; ++i) { m = &BIO_MSG_N(msg, i); l = dgram_pair_write_actual(bio, m->data, m->data_len, m->local, m->peer, 1); if (l < 0) { *num_processed = i; if (i > 0) { ret = 1; } else { ERR_raise(ERR_LIB_BIO, -l); ret = 0; } goto out; } m->flags = 0; } *num_processed = i; ret = 1; out: CRYPTO_THREAD_unlock(b->lock); return ret; } #endif