|
1 |
| -#define _XOPEN_SOURCE // IOV_MAX |
| 1 | +// Test for MinGW. |
| 2 | +#if defined(__MINGW32__) || defined(__MINGW64__) |
| 3 | +# define MINGW |
| 4 | +#endif |
| 5 | + |
| 6 | +// Decide if the writev(2) system call needs to be emulated as a series of |
| 7 | +// write(2) calls. At least MinGW does not support writev(2). |
| 8 | +#ifdef MINGW |
| 9 | +# define EMULATE_WRITEV |
| 10 | +#endif |
| 11 | + |
| 12 | +// Include the necessary system header when using the system's writev(2). |
| 13 | +#ifndef EMULATE_WRITEV |
| 14 | +# define _XOPEN_SOURCE // Unlock IOV_MAX |
| 15 | +# include <sys/uio.h> |
| 16 | +#endif |
2 | 17 |
|
3 | 18 | #include <stdbool.h>
|
4 | 19 | #include <stdlib.h>
|
|
8 | 23 | #include <getopt.h>
|
9 | 24 | #include <errno.h>
|
10 | 25 | #include <limits.h>
|
11 |
| -#include <sys/uio.h> |
| 26 | + |
12 | 27 | #include "../include/libbase64.h"
|
13 | 28 |
|
14 | 29 | // Size of the buffer for the "raw" (not base64-encoded) data in bytes.
|
@@ -50,6 +65,59 @@ struct buffer {
|
50 | 65 | char *enc;
|
51 | 66 | };
|
52 | 67 |
|
| 68 | +// Optionally emulate writev(2) as a series of write calls. |
| 69 | +#ifdef EMULATE_WRITEV |
| 70 | + |
| 71 | +// Quick and dirty definition of IOV_MAX as it is probably not defined. |
| 72 | +#ifndef IOV_MAX |
| 73 | +# define IOV_MAX 1024 |
| 74 | +#endif |
| 75 | + |
| 76 | +// Quick and dirty definition of this system struct, for local use only. |
| 77 | +struct iovec { |
| 78 | + |
| 79 | + // Opaque data pointer. |
| 80 | + void *iov_base; |
| 81 | + |
| 82 | + // Length of the data in bytes. |
| 83 | + size_t iov_len; |
| 84 | +}; |
| 85 | + |
| 86 | +static ssize_t |
| 87 | +writev (const int fd, const struct iovec *iov, int iovcnt) |
| 88 | +{ |
| 89 | + ssize_t r, nwrite = 0; |
| 90 | + |
| 91 | + // Reset the error marker. |
| 92 | + errno = 0; |
| 93 | + |
| 94 | + while (iovcnt-- > 0) { |
| 95 | + |
| 96 | + // Write the vector; propagate errors back to the caller. Note |
| 97 | + // that this loses information about how much vectors have been |
| 98 | + // successfully written, but that also seems to be the case |
| 99 | + // with the real function. The API is somewhat flawed. |
| 100 | + if ((r = write(fd, iov->iov_base, iov->iov_len)) < 0) { |
| 101 | + return r; |
| 102 | + } |
| 103 | + |
| 104 | + // Update the total write count. |
| 105 | + nwrite += r; |
| 106 | + |
| 107 | + // Return early after a partial write; the caller should retry. |
| 108 | + if ((size_t) r != iov->iov_len) { |
| 109 | + break; |
| 110 | + } |
| 111 | + |
| 112 | + // Move to the next vector. |
| 113 | + iov++; |
| 114 | + } |
| 115 | + |
| 116 | + return nwrite; |
| 117 | +} |
| 118 | + |
| 119 | +#endif // EMULATE_WRITEV |
| 120 | + |
53 | 121 | static bool
|
54 | 122 | buffer_alloc (const struct config *config, struct buffer *buf)
|
55 | 123 | {
|
@@ -272,29 +340,75 @@ encode (const struct config *config, struct buffer *buf)
|
272 | 340 | return true;
|
273 | 341 | }
|
274 | 342 |
|
275 |
| -static int |
| 343 | +static inline size_t |
| 344 | +find_newline (const char *p, const size_t avail) |
| 345 | +{ |
| 346 | + // This is very naive and can probably be improved by vectorization. |
| 347 | + for (size_t len = 0; len < avail; len++) { |
| 348 | + if (p[len] == '\n') { |
| 349 | + return len; |
| 350 | + } |
| 351 | + } |
| 352 | + |
| 353 | + return avail; |
| 354 | +} |
| 355 | + |
| 356 | +static bool |
276 | 357 | decode (const struct config *config, struct buffer *buf)
|
277 | 358 | {
|
278 |
| - size_t nread, nout; |
| 359 | + size_t avail; |
279 | 360 | struct base64_state state;
|
280 | 361 |
|
281 | 362 | // Initialize the decoder's state structure.
|
282 | 363 | base64_stream_decode_init(&state, 0);
|
283 | 364 |
|
284 | 365 | // Read encoded data into the buffer. Use the smallest buffer size to
|
285 | 366 | // be on the safe side: the decoded output will fit the raw buffer.
|
286 |
| - while ((nread = fread(buf->enc, 1, BUFFER_RAW_SIZE, config->fp)) > 0) { |
| 367 | + while ((avail = fread(buf->enc, 1, BUFFER_RAW_SIZE, config->fp)) > 0) { |
| 368 | + char *start = buf->enc; |
| 369 | + char *outbuf = buf->raw; |
| 370 | + size_t ototal = 0; |
| 371 | + |
| 372 | + // By popular demand, this utility tries to be bug-compatible |
| 373 | + // with GNU `base64'. That includes silently ignoring newlines |
| 374 | + // in the input. Tokenize the input on newline characters. |
| 375 | + while (avail > 0) { |
| 376 | + |
| 377 | + // Find the offset of the next newline character, which |
| 378 | + // is also the length of the next chunk. |
| 379 | + size_t outlen, len = find_newline(start, avail); |
| 380 | + |
| 381 | + // Ignore empty chunks. |
| 382 | + if (len == 0) { |
| 383 | + start++; |
| 384 | + avail--; |
| 385 | + continue; |
| 386 | + } |
287 | 387 |
|
288 |
| - // Decode the input into the raw buffer. |
289 |
| - if (base64_stream_decode(&state, buf->enc, nread, |
290 |
| - buf->raw, &nout) == 0) { |
291 |
| - fprintf(stderr, "%s: %s: decoding error\n", |
292 |
| - config->name, config->file); |
293 |
| - return false; |
| 388 | + // Decode the chunk into the raw buffer. |
| 389 | + if (base64_stream_decode(&state, start, len, |
| 390 | + outbuf, &outlen) == 0) { |
| 391 | + fprintf(stderr, "%s: %s: decoding error\n", |
| 392 | + config->name, config->file); |
| 393 | + return false; |
| 394 | + } |
| 395 | + |
| 396 | + // Update the output buffer pointer and total size. |
| 397 | + outbuf += outlen; |
| 398 | + ototal += outlen; |
| 399 | + |
| 400 | + // Bail out if the whole string has been consumed. |
| 401 | + if (len == avail) { |
| 402 | + break; |
| 403 | + } |
| 404 | + |
| 405 | + // Move the start pointer past the newline. |
| 406 | + start += len + 1; |
| 407 | + avail -= len + 1; |
294 | 408 | }
|
295 | 409 |
|
296 | 410 | // Append the raw data to the output stream.
|
297 |
| - if (write_stdout(config, buf->raw, nout) == false) { |
| 411 | + if (write_stdout(config, buf->raw, ototal) == false) { |
298 | 412 | return false;
|
299 | 413 | }
|
300 | 414 | }
|
|
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