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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
commit | f7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch) | |
tree | a3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib/iostream-temp.c | |
parent | Initial commit. (diff) | |
download | dovecot-upstream.tar.xz dovecot-upstream.zip |
Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/lib/iostream-temp.c')
-rw-r--r-- | src/lib/iostream-temp.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/src/lib/iostream-temp.c b/src/lib/iostream-temp.c new file mode 100644 index 0000000..6e14ff5 --- /dev/null +++ b/src/lib/iostream-temp.c @@ -0,0 +1,404 @@ +/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "buffer.h" +#include "str.h" +#include "safe-mkstemp.h" +#include "write-full.h" +#include "istream-private.h" +#include "ostream-private.h" +#include "iostream-temp.h" + +#include <unistd.h> + +#define IOSTREAM_TEMP_MAX_BUF_SIZE_DEFAULT (1024*128) + +struct temp_ostream { + struct ostream_private ostream; + + char *temp_path_prefix; + enum iostream_temp_flags flags; + size_t max_mem_size; + + struct istream *dupstream; + uoff_t dupstream_offset, dupstream_start_offset; + char *name; + + buffer_t *buf; + int fd; + bool fd_tried; + uoff_t fd_size; +}; + +static bool o_stream_temp_dup_cancel(struct temp_ostream *tstream, + enum ostream_send_istream_result *res_r); + +static void +o_stream_temp_close(struct iostream_private *stream, + bool close_parent ATTR_UNUSED) +{ + struct temp_ostream *tstream = + container_of(stream, struct temp_ostream, ostream.iostream); + + i_close_fd(&tstream->fd); + buffer_free(&tstream->buf); + i_free(tstream->temp_path_prefix); + i_free(tstream->name); +} + +static int o_stream_temp_move_to_fd(struct temp_ostream *tstream) +{ + string_t *path; + + if (tstream->fd_tried) + return -1; + tstream->fd_tried = TRUE; + + path = t_str_new(128); + str_append(path, tstream->temp_path_prefix); + tstream->fd = safe_mkstemp_hostpid(path, 0600, (uid_t)-1, (gid_t)-1); + if (tstream->fd == -1) { + i_error("safe_mkstemp(%s) failed: %m", str_c(path)); + return -1; + } + if (i_unlink(str_c(path)) < 0) { + i_close_fd(&tstream->fd); + return -1; + } + if (write_full(tstream->fd, tstream->buf->data, tstream->buf->used) < 0) { + i_error("write(%s) failed: %m", str_c(path)); + i_close_fd(&tstream->fd); + return -1; + } + /* make the fd available also to o_stream_get_fd(), + e.g. for unit tests */ + tstream->ostream.fd = tstream->fd; + tstream->fd_size = tstream->buf->used; + buffer_free(&tstream->buf); + return 0; +} + +int o_stream_temp_move_to_memory(struct ostream *output) +{ + struct temp_ostream *tstream = + container_of(output->real_stream, struct temp_ostream, ostream); + unsigned char buf[IO_BLOCK_SIZE]; + uoff_t offset = 0; + ssize_t ret = 0; + + i_assert(tstream->buf == NULL); + tstream->buf = buffer_create_dynamic(default_pool, 8192); + while (offset < tstream->ostream.ostream.offset && + (ret = pread(tstream->fd, buf, sizeof(buf), offset)) > 0) { + if ((size_t)ret > tstream->ostream.ostream.offset - offset) + ret = tstream->ostream.ostream.offset - offset; + buffer_append(tstream->buf, buf, ret); + offset += ret; + } + if (ret < 0) { + /* not really expecting this to happen */ + i_error("iostream-temp %s: read(%s*) failed: %m", + o_stream_get_name(&tstream->ostream.ostream), + tstream->temp_path_prefix); + tstream->ostream.ostream.stream_errno = EIO; + return -1; + } + i_close_fd(&tstream->fd); + tstream->ostream.fd = -1; + return 0; +} + +static ssize_t +o_stream_temp_fd_sendv(struct temp_ostream *tstream, + const struct const_iovec *iov, unsigned int iov_count) +{ + size_t bytes = 0; + unsigned int i; + + for (i = 0; i < iov_count; i++) { + if (write_full(tstream->fd, iov[i].iov_base, iov[i].iov_len) < 0) { + i_error("iostream-temp %s: write(%s*) failed: %m - moving to memory", + o_stream_get_name(&tstream->ostream.ostream), + tstream->temp_path_prefix); + if (o_stream_temp_move_to_memory(&tstream->ostream.ostream) < 0) + return -1; + for (; i < iov_count; i++) { + buffer_append(tstream->buf, iov[i].iov_base, iov[i].iov_len); + bytes += iov[i].iov_len; + tstream->ostream.ostream.offset += iov[i].iov_len; + } + i_assert(tstream->fd_tried); + return bytes; + } + bytes += iov[i].iov_len; + tstream->ostream.ostream.offset += iov[i].iov_len; + } + tstream->fd_size += bytes; + return bytes; +} + +static ssize_t +o_stream_temp_sendv(struct ostream_private *stream, + const struct const_iovec *iov, unsigned int iov_count) +{ + struct temp_ostream *tstream = + container_of(stream, struct temp_ostream, ostream); + ssize_t ret = 0; + unsigned int i; + enum ostream_send_istream_result res; + + + tstream->flags &= ENUM_NEGATE(IOSTREAM_TEMP_FLAG_TRY_FD_DUP); + if (tstream->dupstream != NULL) { + if (o_stream_temp_dup_cancel(tstream, &res)) + return -1; + } + + if (tstream->fd != -1) + return o_stream_temp_fd_sendv(tstream, iov, iov_count); + + for (i = 0; i < iov_count; i++) { + if (tstream->buf->used + iov[i].iov_len > tstream->max_mem_size) { + if (o_stream_temp_move_to_fd(tstream) == 0) { + i_assert(tstream->fd != -1); + return o_stream_temp_fd_sendv(tstream, iov+i, + iov_count-i); + } + /* failed to move to temp fd, just keep it in memory */ + } + buffer_append(tstream->buf, iov[i].iov_base, iov[i].iov_len); + ret += iov[i].iov_len; + stream->ostream.offset += iov[i].iov_len; + } + return ret; +} + +static bool o_stream_temp_dup_cancel(struct temp_ostream *tstream, + enum ostream_send_istream_result *res_r) +{ + struct istream *input; + uoff_t size = tstream->dupstream_offset - + tstream->dupstream_start_offset; + bool ret = TRUE; /* use res_r to return error */ + + i_stream_seek(tstream->dupstream, tstream->dupstream_start_offset); + tstream->ostream.ostream.offset = 0; + + input = i_stream_create_limit(tstream->dupstream, size); + i_stream_unref(&tstream->dupstream); + + *res_r = io_stream_copy(&tstream->ostream.ostream, input); + switch (*res_r) { + case OSTREAM_SEND_ISTREAM_RESULT_FINISHED: + /* everything copied */ + ret = FALSE; + break; + case OSTREAM_SEND_ISTREAM_RESULT_WAIT_INPUT: + case OSTREAM_SEND_ISTREAM_RESULT_WAIT_OUTPUT: + i_unreached(); + case OSTREAM_SEND_ISTREAM_RESULT_ERROR_INPUT: + tstream->ostream.ostream.stream_errno = input->stream_errno; + io_stream_set_error(&tstream->ostream.iostream, + "iostream-temp: read(%s) failed: %s", + i_stream_get_name(input), + i_stream_get_error(input)); + break; + case OSTREAM_SEND_ISTREAM_RESULT_ERROR_OUTPUT: + break; + } + i_stream_destroy(&input); + return ret; +} + +static bool +o_stream_temp_dup_istream(struct temp_ostream *outstream, + struct istream *instream, + enum ostream_send_istream_result *res_r) +{ + uoff_t in_size; + + if (!instream->readable_fd || i_stream_get_fd(instream) == -1) + return FALSE; + + if (i_stream_get_size(instream, TRUE, &in_size) <= 0) { + if (outstream->dupstream != NULL) + return o_stream_temp_dup_cancel(outstream, res_r); + return FALSE; + } + i_assert(instream->v_offset <= in_size); + + if (outstream->dupstream == NULL) { + outstream->dupstream = instream; + outstream->dupstream_start_offset = instream->v_offset; + i_stream_ref(outstream->dupstream); + } else { + if (outstream->dupstream != instream || + outstream->dupstream_offset != instream->v_offset || + outstream->dupstream_offset > in_size) + return o_stream_temp_dup_cancel(outstream, res_r); + } + i_stream_seek(instream, in_size); + /* we should be at EOF now. o_stream_send_istream() asserts if + eof isn't set. */ + instream->eof = TRUE; + outstream->dupstream_offset = instream->v_offset; + outstream->ostream.ostream.offset = + outstream->dupstream_offset - outstream->dupstream_start_offset; + *res_r = OSTREAM_SEND_ISTREAM_RESULT_FINISHED; + return TRUE; +} + +static enum ostream_send_istream_result +o_stream_temp_send_istream(struct ostream_private *_outstream, + struct istream *instream) +{ + struct temp_ostream *outstream = + container_of(_outstream, struct temp_ostream, ostream); + enum ostream_send_istream_result res; + + if ((outstream->flags & IOSTREAM_TEMP_FLAG_TRY_FD_DUP) != 0) { + if (o_stream_temp_dup_istream(outstream, instream, &res)) + return res; + outstream->flags &= ENUM_NEGATE(IOSTREAM_TEMP_FLAG_TRY_FD_DUP); + } + return io_stream_copy(&outstream->ostream.ostream, instream); +} + +static int +o_stream_temp_write_at(struct ostream_private *stream, + const void *data, size_t size, uoff_t offset) +{ + struct temp_ostream *tstream = + container_of(stream, struct temp_ostream, ostream); + + if (tstream->fd == -1) { + i_assert(stream->ostream.offset == tstream->buf->used); + buffer_write(tstream->buf, offset, data, size); + stream->ostream.offset = tstream->buf->used; + } else { + if (pwrite_full(tstream->fd, data, size, offset) < 0) { + stream->ostream.stream_errno = errno; + i_close_fd(&tstream->fd); + return -1; + } + if (tstream->fd_size < offset + size) + tstream->fd_size = offset + size; + } + return 0; +} + +static int o_stream_temp_seek(struct ostream_private *_stream, uoff_t offset) +{ + _stream->ostream.offset = offset; + return 0; +} + +struct ostream *iostream_temp_create(const char *temp_path_prefix, + enum iostream_temp_flags flags) +{ + return iostream_temp_create_named(temp_path_prefix, flags, ""); +} + +struct ostream *iostream_temp_create_named(const char *temp_path_prefix, + enum iostream_temp_flags flags, + const char *name) +{ + return iostream_temp_create_sized(temp_path_prefix, flags, name, + IOSTREAM_TEMP_MAX_BUF_SIZE_DEFAULT); +} + +struct ostream *iostream_temp_create_sized(const char *temp_path_prefix, + enum iostream_temp_flags flags, + const char *name, + size_t max_mem_size) +{ + struct temp_ostream *tstream; + struct ostream *output; + + tstream = i_new(struct temp_ostream, 1); + tstream->ostream.ostream.blocking = TRUE; + tstream->ostream.sendv = o_stream_temp_sendv; + tstream->ostream.send_istream = o_stream_temp_send_istream; + tstream->ostream.write_at = o_stream_temp_write_at; + tstream->ostream.seek = o_stream_temp_seek; + tstream->ostream.iostream.close = o_stream_temp_close; + tstream->temp_path_prefix = i_strdup(temp_path_prefix); + tstream->flags = flags; + tstream->max_mem_size = max_mem_size; + tstream->buf = buffer_create_dynamic(default_pool, 8192); + tstream->fd = -1; + + output = o_stream_create(&tstream->ostream, NULL, -1); + tstream->name = i_strdup(name); + if (name[0] == '\0') { + o_stream_set_name(output, t_strdup_printf( + "(temp iostream in %s)", temp_path_prefix)); + } else { + o_stream_set_name(output, t_strdup_printf( + "(temp iostream in %s for %s)", temp_path_prefix, name)); + } + return output; +} + +static void iostream_temp_buf_destroyed(buffer_t *buf) +{ + buffer_free(&buf); +} + +struct istream *iostream_temp_finish(struct ostream **output, + size_t max_buffer_size) +{ + struct temp_ostream *tstream = + container_of((*output)->real_stream, struct temp_ostream, + ostream); + struct istream *input, *input2; + uoff_t abs_offset, size; + const char *for_path; + int fd; + + if (tstream->name[0] == '\0') + for_path = ""; + else + for_path = t_strdup_printf(" for %s", tstream->name); + + if (tstream->dupstream != NULL && !tstream->dupstream->closed) { + abs_offset = i_stream_get_absolute_offset(tstream->dupstream) - + tstream->dupstream->v_offset + + tstream->dupstream_start_offset; + size = tstream->dupstream_offset - + tstream->dupstream_start_offset; + fd = dup(i_stream_get_fd(tstream->dupstream)); + if (fd == -1) + input = i_stream_create_error_str(errno, "dup() failed: %m"); + else { + input2 = i_stream_create_fd_autoclose(&fd, max_buffer_size); + i_stream_seek(input2, abs_offset); + input = i_stream_create_limit(input2, size); + i_stream_unref(&input2); + } + i_stream_set_name(input, t_strdup_printf( + "(Temp file in %s%s, from %s)", tstream->temp_path_prefix, + for_path, i_stream_get_name(tstream->dupstream))); + i_stream_unref(&tstream->dupstream); + } else if (tstream->dupstream != NULL) { + /* return the original failed stream. */ + input = tstream->dupstream; + } else if (tstream->fd != -1) { + int fd = tstream->fd; + input = i_stream_create_fd_autoclose(&tstream->fd, max_buffer_size); + i_stream_set_name(input, t_strdup_printf( + "(Temp file fd %d in %s%s, %"PRIuUOFF_T" bytes)", + fd, tstream->temp_path_prefix, for_path, tstream->fd_size)); + } else { + input = i_stream_create_from_data(tstream->buf->data, + tstream->buf->used); + i_stream_set_name(input, t_strdup_printf( + "(Temp buffer in %s%s, %zu bytes)", + tstream->temp_path_prefix, for_path, tstream->buf->used)); + i_stream_add_destroy_callback(input, iostream_temp_buf_destroyed, + tstream->buf); + tstream->buf = NULL; + } + o_stream_destroy(output); + return input; +} |