diff options
Diffstat (limited to 'third_party/heimdal/lib/krb5/store_stdio.c')
| -rw-r--r-- | third_party/heimdal/lib/krb5/store_stdio.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/store_stdio.c b/third_party/heimdal/lib/krb5/store_stdio.c new file mode 100644 index 0000000..9244b9e --- /dev/null +++ b/third_party/heimdal/lib/krb5/store_stdio.c @@ -0,0 +1,271 @@ +/* + * Copyright (c) 2017 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "krb5_locl.h" +#include "store-int.h" + +#ifndef HAVE_FSEEKO +#define fseeko fseek +#define ftello ftell +#endif + +typedef struct stdio_storage { + FILE *f; + off_t pos; +} stdio_storage; + +#define F(S) (((stdio_storage*)(S)->data)->f) +#define POS(S) (((stdio_storage*)(S)->data)->pos) + +static ssize_t +stdio_fetch(krb5_storage * sp, void *data, size_t size) +{ + char *cbuf = (char *)data; + ssize_t count; + size_t rem = size; + + /* similar pattern to net_read() to support pipes */ + while (rem > 0) { + count = fread(cbuf, 1, rem, F(sp)); + if (count < 0) { + POS(sp) = -1; + if (errno == EINTR) + continue; + else + return count; + } else if (count == 0) { + if (POS(sp) >= 0) + POS(sp) += size - rem; + return size - rem; + } + cbuf += count; + rem -= count; + } + if (POS(sp) >= 0) + POS(sp) += size; + return size; +} + +static ssize_t +stdio_store(krb5_storage * sp, const void *data, size_t size) +{ + const char *cbuf = (const char *)data; + ssize_t count; + size_t rem = size; + + /* + * It's possible we just went from reading to writing if the file was open + * for both. Per C99 (N869 final draft) section 7.18.5.3, point 6, when + * going from reading to writing [a file opened for both] one must seek. + */ + (void) fseeko(F(sp), 0, SEEK_CUR); + + /* similar pattern to net_write() to support pipes */ + while (rem > 0) { + count = fwrite(cbuf, 1, rem, F(sp)); + if (count < 0) { + if (errno == EINTR) + continue; + /* + * What does it mean to have a short write when using stdio? + * + * It can't mean much. After all stdio is buffering, so + * earlier writes that appeared complete may have failed, + * and so we don't know how much we really failed to write. + */ + POS(sp) = -1; + return -1; + } + if (count == 0) { + POS(sp) = -1; + return -1; + } + cbuf += count; + rem -= count; + } + if (POS(sp) >= 0) + POS(sp) += size; + return size; +} + +static off_t +stdio_seek(krb5_storage * sp, off_t offset, int whence) +{ + int save_errno = errno; + + if (whence == SEEK_SET && POS(sp) == offset) + return POS(sp); + + if (whence == SEEK_CUR && POS(sp) >= 0 && offset == 0) + return POS(sp); + + if (fseeko(F(sp), offset, whence) != 0) + return -1; + errno = save_errno; + return POS(sp) = ftello(F(sp)); +} + +static int +stdio_trunc(krb5_storage * sp, off_t offset) +{ + off_t tmpoff; + int save_errno = errno; + + if (fflush(F(sp)) == EOF) + return errno; + tmpoff = ftello(F(sp)); + if (tmpoff < 0) + return errno; + if (tmpoff > offset) + tmpoff = offset; + if (ftruncate(fileno(F(sp)), offset) == -1) + return errno; + if (fseeko(F(sp), 0, SEEK_END) == -1) + return errno; + if (fseeko(F(sp), tmpoff, SEEK_SET) == -1) + return errno; + errno = save_errno; + POS(sp) = tmpoff; + return 0; +} + +static int +stdio_sync(krb5_storage * sp) +{ + if (fflush(F(sp)) == EOF) + return errno; + if (fsync(fileno(F(sp))) == -1) + return errno; + return 0; +} + +static void +stdio_free(krb5_storage * sp) +{ + int save_errno = errno; + + if (F(sp) != NULL && fclose(F(sp)) == 0) + errno = save_errno; + F(sp) = NULL; +} + +/** + * Open a krb5_storage using stdio for buffering. + * + * @return A krb5_storage on success, or NULL on out of memory error. + * + * @ingroup krb5_storage + * + * @sa krb5_storage_emem() + * @sa krb5_storage_from_fd() + * @sa krb5_storage_from_mem() + * @sa krb5_storage_from_readonly_mem() + * @sa krb5_storage_from_data() + * @sa krb5_storage_from_socket() + */ + +KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL +krb5_storage_stdio_from_fd(int fd_in, const char *mode) +{ + krb5_storage *sp; + off_t off; + FILE *f; + int saved_errno = errno; + int fd; + + off = lseek(fd_in, 0, SEEK_CUR); + if (off == -1) + return NULL; + +#ifdef _MSC_VER + /* + * This function used to try to pass the input to + * _get_osfhandle() to test if the value is a HANDLE + * but this doesn't work because doing so throws an + * exception that will result in Watson being triggered + * to file a Windows Error Report. + */ + fd = _dup(fd_in); +#else + fd = dup(fd_in); +#endif + + if (fd < 0) + return NULL; + + f = fdopen(fd, mode); + if (f == NULL) { + (void) close(fd); + return NULL; + } + + errno = saved_errno; + + if (fseeko(f, off, SEEK_SET) == -1) { + saved_errno = errno; + (void) fclose(f); + errno = saved_errno; + return NULL; + } + + errno = ENOMEM; + sp = malloc(sizeof(krb5_storage)); + if (sp == NULL) { + saved_errno = errno; + (void) fclose(f); + errno = saved_errno; + return NULL; + } + + errno = ENOMEM; + sp->data = malloc(sizeof(stdio_storage)); + if (sp->data == NULL) { + saved_errno = errno; + (void) fclose(f); + free(sp); + errno = saved_errno; + return NULL; + } + sp->flags = 0; + sp->eof_code = HEIM_ERR_EOF; + F(sp) = f; + POS(sp) = off; + sp->fetch = stdio_fetch; + sp->store = stdio_store; + sp->seek = stdio_seek; + sp->trunc = stdio_trunc; + sp->fsync = stdio_sync; + sp->free = stdio_free; + sp->max_alloc = UINT32_MAX/64; + return sp; +} |