diff --git a/common/membuf.c b/common/membuf.c index 009fbc336..60491b590 100644 --- a/common/membuf.c +++ b/common/membuf.c @@ -1,233 +1,245 @@ /* membuf.c - A simple implementation of a dynamic buffer. * Copyright (C) 2001, 2003, 2009, 2011 Free Software Foundation, Inc. * Copyright (C) 2013 Werner Koch * * This file is part of GnuPG. * * This file is free software; you can redistribute it and/or modify * it under the terms of either * * - the GNU Lesser General Public License as published by the Free * Software Foundation; either version 3 of the License, or (at * your option) any later version. * * or * * - the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at * your option) any later version. * * or both in parallel, as here. * * This file is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #include #include #include #include #include "util.h" #include "membuf.h" /* A simple implementation of a dynamic buffer. Use init_membuf() to create a buffer, put_membuf to append bytes and get_membuf to release and return the buffer. Allocation errors are detected but only returned at the final get_membuf(), this helps not to clutter the code with out of core checks. */ void init_membuf (membuf_t *mb, int initiallen) { mb->len = 0; mb->size = initiallen; mb->out_of_core = 0; mb->buf = xtrymalloc (initiallen); if (!mb->buf) mb->out_of_core = errno; } /* Same as init_membuf but allocates the buffer in secure memory. */ void init_membuf_secure (membuf_t *mb, int initiallen) { mb->len = 0; mb->size = initiallen; mb->out_of_core = 0; mb->buf = xtrymalloc_secure (initiallen); if (!mb->buf) mb->out_of_core = errno; } /* Shift the content of the membuf MB by AMOUNT bytes. The next operation will then behave as if AMOUNT bytes had not been put into the buffer. If AMOUNT is greater than the actual accumulated bytes, the membuf is basically reset to its initial state. */ void clear_membuf (membuf_t *mb, size_t amount) { /* No need to clear if we are already out of core. */ if (mb->out_of_core) return; if (amount >= mb->len) mb->len = 0; else { mb->len -= amount; memmove (mb->buf, mb->buf+amount, mb->len); } } void put_membuf (membuf_t *mb, const void *buf, size_t len) { if (mb->out_of_core || !len) return; if (mb->len + len >= mb->size) { char *p; mb->size += len + 1024; p = xtryrealloc (mb->buf, mb->size); if (!p) { mb->out_of_core = errno ? errno : ENOMEM; /* Wipe out what we already accumulated. This is required in case we are storing sensitive data here. The membuf API does not provide another way to cleanup after an error. */ wipememory (mb->buf, mb->len); return; } mb->buf = p; } if (buf) memcpy (mb->buf + mb->len, buf, len); else memset (mb->buf + mb->len, 0, len); mb->len += len; } /* A variant of put_membuf accepting a void * and returning a gpg_error_t (which will always return 0) to be used as a generic callback handler. This function also allows buffer to be NULL. */ gpg_error_t put_membuf_cb (void *opaque, const void *buf, size_t len) { membuf_t *data = opaque; if (buf) put_membuf (data, buf, len); return 0; } void put_membuf_str (membuf_t *mb, const char *string) { put_membuf (mb, string, strlen (string)); } void put_membuf_printf (membuf_t *mb, const char *format, ...) { int rc; va_list arg_ptr; char *buf; va_start (arg_ptr, format); rc = gpgrt_vasprintf (&buf, format, arg_ptr); if (rc < 0) mb->out_of_core = errno ? errno : ENOMEM; va_end (arg_ptr); if (rc >= 0) { put_membuf (mb, buf, strlen (buf)); xfree (buf); } } void * get_membuf (membuf_t *mb, size_t *len) { char *p; if (mb->out_of_core) { if (mb->buf) { wipememory (mb->buf, mb->len); xfree (mb->buf); mb->buf = NULL; } gpg_err_set_errno (mb->out_of_core); return NULL; } p = mb->buf; if (len) *len = mb->len; mb->buf = NULL; mb->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */ return p; } /* Same as get_membuf but shrinks the reallocated space to the required size. */ void * get_membuf_shrink (membuf_t *mb, size_t *len) { void *p, *pp; size_t dummylen; if (!len) len = &dummylen; p = get_membuf (mb, len); if (!p) return NULL; if (*len) { pp = xtryrealloc (p, *len); if (pp) p = pp; } return p; } /* Peek at the membuf MB. On success a pointer to the buffer is returned which is valid until the next operation on MB. If LEN is not NULL the current LEN of the buffer is stored there. On error NULL is returned and ERRNO is set. */ const void * peek_membuf (membuf_t *mb, size_t *len) { const char *p; if (mb->out_of_core) { gpg_err_set_errno (mb->out_of_core); return NULL; } p = mb->buf; if (len) *len = mb->len; return p; } + +/* To assist using membuf with function returning an error, this + * function sets the membuf into the error state. */ +void +set_membuf_err (membuf_t *mb, gpg_error_t err) +{ + if (!mb->out_of_core) + { + int myerr = gpg_err_code_to_errno (gpg_err_code (err)); + mb->out_of_core = myerr? myerr : EINVAL; + } +} diff --git a/common/membuf.h b/common/membuf.h index 1497bcd04..4b2be1a71 100644 --- a/common/membuf.h +++ b/common/membuf.h @@ -1,64 +1,65 @@ /* membuf.h - A simple implementation of a dynamic buffer * Copyright (C) 2001, 2003 Free Software Foundation, Inc. * * This file is part of GnuPG. * * This file is free software; you can redistribute it and/or modify * it under the terms of either * * - the GNU Lesser General Public License as published by the Free * Software Foundation; either version 3 of the License, or (at * your option) any later version. * * or * * - the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at * your option) any later version. * * or both in parallel, as here. * * This file is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #ifndef GNUPG_COMMON_MEMBUF_H #define GNUPG_COMMON_MEMBUF_H #include "mischelp.h" /* The definition of the structure is private, we only need it here, so it can be allocated on the stack. */ struct private_membuf_s { size_t len; size_t size; char *buf; int out_of_core; }; typedef struct private_membuf_s membuf_t; /* Return the current length of the membuf. */ #define get_membuf_len(a) ((a)->len) #define is_membuf_ready(a) ((a)->buf || (a)->out_of_core) #define MEMBUF_ZERO { 0, 0, NULL, 0} void init_membuf (membuf_t *mb, int initiallen); void init_membuf_secure (membuf_t *mb, int initiallen); void clear_membuf (membuf_t *mb, size_t amount); void put_membuf (membuf_t *mb, const void *buf, size_t len); gpg_error_t put_membuf_cb (void *opaque, const void *buf, size_t len); void put_membuf_str (membuf_t *mb, const char *string); void put_membuf_printf (membuf_t *mb, const char *format, ...) GPGRT_ATTR_PRINTF(2,3); void *get_membuf (membuf_t *mb, size_t *len); void *get_membuf_shrink (membuf_t *mb, size_t *len); const void *peek_membuf (membuf_t *mb, size_t *len); +void set_membuf_err (membuf_t *mb, gpg_error_t err); #endif /*GNUPG_COMMON_MEMBUF_H*/