| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2014 Travis Geiselbrecht |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <err.h> |
| 24 | #include <debug.h> |
| 25 | #include <assert.h> |
| 26 | #include <string.h> |
| 27 | #include <sys/types.h> |
| 28 | |
| 29 | #include <iovec.h> |
| 30 | |
| 31 | #define LOCAL_TRACE 0 |
| 32 | |
| 33 | /* |
| 34 | * Calc total size of iovec buffers |
| 35 | */ |
| 36 | ssize_t iovec_size (const iovec_t *iov, uint iov_cnt) |
| 37 | { |
| 38 | if (!iov) |
| 39 | return (ssize_t) ERR_INVALID_ARGS; |
| 40 | |
| 41 | size_t c = 0; |
| 42 | for (uint i = 0; i < iov_cnt; i++, iov++) { |
| 43 | c += iov->iov_len; |
| 44 | } |
| 45 | return (ssize_t) c; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Copy out portion of iovec started from given position |
| 50 | * into single buffer |
| 51 | */ |
| 52 | ssize_t iovec_to_membuf (uint8_t *buf, uint buf_len, const iovec_t *iov, uint iov_cnt, uint iov_pos) |
| 53 | { |
| 54 | uint buf_pos = 0; |
| 55 | |
| 56 | if (!buf || !iov) |
| 57 | return (ssize_t) ERR_INVALID_ARGS; |
| 58 | |
| 59 | /* for all iovec */ |
| 60 | for (uint i = 0; i < iov_cnt; i++, iov++) { |
| 61 | |
| 62 | if (iov_pos >= iov->iov_len) { |
| 63 | iov_pos -= iov->iov_len; /* skip whole chunks */ |
| 64 | continue; |
| 65 | } |
| 66 | |
| 67 | /* calc number of bytes left in current iov */ |
| 68 | size_t to_copy = (size_t) (iov->iov_len - iov_pos); |
| 69 | |
| 70 | /* limit it to number of bytes left in buffer */ |
| 71 | if (to_copy > buf_len) |
| 72 | to_copy = buf_len; |
| 73 | |
| 74 | /* copy data out */ |
| 75 | memcpy (buf + buf_pos, (uint8_t *)iov->iov_base + iov_pos, to_copy); |
| 76 | |
| 77 | /* advance in buffer position */ |
| 78 | buf_pos += to_copy; |
| 79 | buf_len -= to_copy; |
| 80 | |
| 81 | /* check if we need to copy more data */ |
| 82 | if (buf_len == 0) |
| 83 | break; |
| 84 | |
| 85 | iov_pos = 0; /* it is only possible to have fully copied iovec here */ |
| 86 | } |
| 87 | |
| 88 | return (ssize_t) buf_pos; |
| 89 | } |
| 90 | |
| 91 | |
| 92 | // vim: set ts=4 sw=4 noexpandtab: |