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-rw-r--r--lib/dpkg/buffer.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/lib/dpkg/buffer.c b/lib/dpkg/buffer.c
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index 0000000..ed05f4b
--- /dev/null
+++ b/lib/dpkg/buffer.c
@@ -0,0 +1,293 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * buffer.c - buffer I/O handling routines
+ *
+ * Copyright © 1999, 2000 Wichert Akkerman <wakkerma@debian.org>
+ * Copyright © 2000-2003 Adam Heath <doogie@debian.org>
+ * Copyright © 2008-2012 Guillem Jover <guillem@debian.org>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of 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.
+ *
+ * This 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <md5.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include <dpkg/i18n.h>
+#include <dpkg/dpkg.h>
+#include <dpkg/varbuf.h>
+#include <dpkg/fdio.h>
+#include <dpkg/buffer.h>
+
+struct buffer_md5_ctx {
+ MD5_CTX ctx;
+ char *hash;
+};
+
+static void
+buffer_md5_init(struct buffer_data *data)
+{
+ struct buffer_md5_ctx *ctx;
+
+ ctx = m_malloc(sizeof(*ctx));
+ ctx->hash = data->arg.ptr;
+ data->arg.ptr = ctx;
+ MD5Init(&ctx->ctx);
+}
+
+static off_t
+buffer_digest_init(struct buffer_data *data)
+{
+ switch (data->type) {
+ case BUFFER_DIGEST_NULL:
+ break;
+ case BUFFER_DIGEST_MD5:
+ buffer_md5_init(data);
+ break;
+ }
+ return 0;
+}
+
+static off_t
+buffer_digest_update(struct buffer_data *digest, const void *buf, off_t length)
+{
+ off_t ret = length;
+
+ switch (digest->type) {
+ case BUFFER_DIGEST_NULL:
+ break;
+ case BUFFER_DIGEST_MD5:
+ MD5Update(&(((struct buffer_md5_ctx *)digest->arg.ptr)->ctx),
+ buf, length);
+ break;
+ default:
+ internerr("unknown data type %i", digest->type);
+ }
+
+ return ret;
+}
+
+static void
+buffer_md5_done(struct buffer_data *data)
+{
+ struct buffer_md5_ctx *ctx;
+ unsigned char digest[16], *p = digest;
+ char *hash;
+ int i;
+
+ ctx = (struct buffer_md5_ctx *)data->arg.ptr;
+ hash = ctx->hash;
+ MD5Final(digest, &ctx->ctx);
+ for (i = 0; i < 16; ++i) {
+ sprintf(hash, "%02x", *p++);
+ hash += 2;
+ }
+ *hash = '\0';
+ free(ctx);
+}
+
+static off_t
+buffer_digest_done(struct buffer_data *data)
+{
+ switch (data->type) {
+ case BUFFER_DIGEST_NULL:
+ break;
+ case BUFFER_DIGEST_MD5:
+ buffer_md5_done(data);
+ break;
+ }
+ return 0;
+}
+
+static off_t
+buffer_write(struct buffer_data *data, const void *buf, off_t length,
+ struct dpkg_error *err)
+{
+ off_t ret = length;
+
+ switch (data->type) {
+ case BUFFER_WRITE_VBUF:
+ varbuf_add_buf((struct varbuf *)data->arg.ptr, buf, length);
+ break;
+ case BUFFER_WRITE_FD:
+ ret = fd_write(data->arg.i, buf, length);
+ if (ret < 0)
+ dpkg_put_errno(err, _("failed to write"));
+ break;
+ case BUFFER_WRITE_NULL:
+ break;
+ default:
+ internerr("unknown data type %i", data->type);
+ }
+
+ return ret;
+}
+
+static off_t
+buffer_read(struct buffer_data *data, void *buf, off_t length,
+ struct dpkg_error *err)
+{
+ off_t ret;
+
+ switch (data->type) {
+ case BUFFER_READ_FD:
+ ret = fd_read(data->arg.i, buf, length);
+ if (ret < 0)
+ dpkg_put_errno(err, _("failed to read"));
+ break;
+ default:
+ internerr("unknown data type %i", data->type);
+ }
+
+ return ret;
+}
+
+off_t
+buffer_digest(const void *input, void *output, int type, off_t limit)
+{
+ struct buffer_data data = { .arg.ptr = output, .type = type };
+ off_t ret;
+
+ buffer_digest_init(&data);
+ ret = buffer_digest_update(&data, input, limit);
+ buffer_digest_done(&data);
+
+ return ret;
+}
+
+static off_t
+buffer_copy(struct buffer_data *read_data,
+ struct buffer_data *digest,
+ struct buffer_data *write_data,
+ off_t limit, struct dpkg_error *err)
+{
+ char *buf;
+ int bufsize = DPKG_BUFFER_SIZE;
+ off_t bytesread = 0, byteswritten = 0;
+ off_t totalread = 0, totalwritten = 0;
+
+ if ((limit != -1) && (limit < bufsize))
+ bufsize = limit;
+ if (bufsize == 0)
+ buf = NULL;
+ else
+ buf = m_malloc(bufsize);
+
+ buffer_digest_init(digest);
+
+ while (bufsize > 0) {
+ bytesread = buffer_read(read_data, buf, bufsize, err);
+ if (bytesread < 0)
+ break;
+ if (bytesread == 0)
+ break;
+
+ totalread += bytesread;
+
+ if (limit != -1) {
+ limit -= bytesread;
+ if (limit < bufsize)
+ bufsize = limit;
+ }
+
+ buffer_digest_update(digest, buf, bytesread);
+
+ byteswritten = buffer_write(write_data, buf, bytesread, err);
+ if (byteswritten < 0)
+ break;
+ if (byteswritten == 0)
+ break;
+
+ totalwritten += byteswritten;
+ }
+
+ buffer_digest_done(digest);
+
+ free(buf);
+
+ if (bytesread < 0 || byteswritten < 0)
+ return -1;
+ if (totalread != totalwritten)
+ return -1;
+ if (limit > 0)
+ return dpkg_put_error(err, _("unexpected end of file or stream"));
+
+ return totalread;
+}
+
+off_t
+buffer_copy_IntInt(int Iin, int Tin,
+ void *Pdigest, int Tdigest,
+ int Iout, int Tout,
+ off_t limit, struct dpkg_error *err)
+{
+ struct buffer_data read_data = { .type = Tin, .arg.i = Iin };
+ struct buffer_data digest = { .type = Tdigest, .arg.ptr = Pdigest };
+ struct buffer_data write_data = { .type = Tout, .arg.i = Iout };
+
+ return buffer_copy(&read_data, &digest, &write_data, limit, err);
+}
+
+off_t
+buffer_copy_IntPtr(int Iin, int Tin,
+ void *Pdigest, int Tdigest,
+ void *Pout, int Tout,
+ off_t limit, struct dpkg_error *err)
+{
+ struct buffer_data read_data = { .type = Tin, .arg.i = Iin };
+ struct buffer_data digest = { .type = Tdigest, .arg.ptr = Pdigest };
+ struct buffer_data write_data = { .type = Tout, .arg.ptr = Pout };
+
+ return buffer_copy(&read_data, &digest, &write_data, limit, err);
+}
+
+static off_t
+buffer_skip(struct buffer_data *input, off_t limit, struct dpkg_error *err)
+{
+ struct buffer_data output;
+ struct buffer_data digest;
+
+ switch (input->type) {
+ case BUFFER_READ_FD:
+ if (lseek(input->arg.i, limit, SEEK_CUR) != -1)
+ return limit;
+ if (errno != ESPIPE)
+ return dpkg_put_errno(err, _("failed to seek"));
+ break;
+ default:
+ internerr("unknown data type %i", input->type);
+ }
+
+ output.type = BUFFER_WRITE_NULL;
+ output.arg.ptr = NULL;
+ digest.type = BUFFER_DIGEST_NULL;
+ digest.arg.ptr = NULL;
+
+ return buffer_copy(input, &digest, &output, limit, err);
+}
+
+off_t
+buffer_skip_Int(int I, int T, off_t limit, struct dpkg_error *err)
+{
+ struct buffer_data input = { .type = T, .arg.i = I };
+
+ return buffer_skip(&input, limit, err);
+}
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