diff options
Diffstat (limited to 'src/shared/edit-util.c')
| -rw-r--r-- | src/shared/edit-util.c | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/src/shared/edit-util.c b/src/shared/edit-util.c new file mode 100644 index 0000000..045839b --- /dev/null +++ b/src/shared/edit-util.c @@ -0,0 +1,370 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <stdio.h> + +#include "alloc-util.h" +#include "copy.h" +#include "edit-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "mkdir-label.h" +#include "path-util.h" +#include "process-util.h" +#include "string-util.h" +#include "strv.h" +#include "tmpfile-util-label.h" + +void edit_file_context_done(EditFileContext *context) { + int r; + + assert(context); + + FOREACH_ARRAY(i, context->files, context->n_files) { + unlink_and_free(i->temp); + + if (context->remove_parent) { + _cleanup_free_ char *parent = NULL; + + r = path_extract_directory(i->path, &parent); + if (r < 0) + log_debug_errno(r, "Failed to extract directory from '%s', ignoring: %m", i->path); + else if (rmdir(parent) < 0 && !IN_SET(errno, ENOENT, ENOTEMPTY)) + log_debug_errno(errno, "Failed to remove parent directory '%s', ignoring: %m", parent); + } + + free(i->path); + free(i->original_path); + strv_free(i->comment_paths); + } + + context->files = mfree(context->files); + context->n_files = 0; +} + +bool edit_files_contains(const EditFileContext *context, const char *path) { + assert(context); + assert(path); + + FOREACH_ARRAY(i, context->files, context->n_files) + if (path_equal(i->path, path)) + return true; + + return false; +} + +int edit_files_add( + EditFileContext *context, + const char *path, + const char *original_path, + char * const *comment_paths) { + + _cleanup_free_ char *new_path = NULL, *new_original_path = NULL; + _cleanup_strv_free_ char **new_comment_paths = NULL; + + assert(context); + assert(path); + + if (edit_files_contains(context, path)) + return 0; + + if (!GREEDY_REALLOC(context->files, context->n_files + 1)) + return log_oom(); + + new_path = strdup(path); + if (!new_path) + return log_oom(); + + if (original_path) { + new_original_path = strdup(original_path); + if (!new_original_path) + return log_oom(); + } + + if (comment_paths) { + new_comment_paths = strv_copy(comment_paths); + if (!new_comment_paths) + return log_oom(); + } + + context->files[context->n_files] = (EditFile) { + .context = context, + .path = TAKE_PTR(new_path), + .original_path = TAKE_PTR(new_original_path), + .comment_paths = TAKE_PTR(new_comment_paths), + }; + context->n_files++; + + return 1; +} + +static int create_edit_temp_file(EditFile *e) { + _cleanup_(unlink_and_freep) char *temp = NULL; + _cleanup_fclose_ FILE *f = NULL; + const char *source; + bool has_original, has_target; + unsigned line = 1; + int r; + + assert(e); + assert(e->context); + assert(e->path); + assert(!e->comment_paths || (e->context->marker_start && e->context->marker_end)); + + if (e->temp) + return 0; + + r = mkdir_parents_label(e->path, 0755); + if (r < 0) + return log_error_errno(r, "Failed to create parent directories for '%s': %m", e->path); + + r = fopen_temporary_label(e->path, e->path, &f, &temp); + if (r < 0) + return log_error_errno(r, "Failed to create temporary file for '%s': %m", e->path); + + if (fchmod(fileno(f), 0644) < 0) + return log_error_errno(errno, "Failed to change mode of temporary file '%s': %m", temp); + + has_original = e->original_path && access(e->original_path, F_OK) >= 0; + has_target = access(e->path, F_OK) >= 0; + + if (has_original && (!has_target || e->context->overwrite_with_origin)) + /* We are asked to overwrite target with original_path or target doesn't exist. */ + source = e->original_path; + else if (has_target) + /* Target exists and shouldn't be overwritten. */ + source = e->path; + else + source = NULL; + + if (e->comment_paths) { + _cleanup_free_ char *source_contents = NULL; + + if (source) { + r = read_full_file(source, &source_contents, NULL); + if (r < 0) + return log_error_errno(r, "Failed to read source file '%s': %m", source); + } + + fprintf(f, + "### Editing %s\n" + "%s\n" + "\n" + "%s%s" + "\n" + "%s\n", + e->path, + e->context->marker_start, + strempty(source_contents), + source_contents && endswith(source_contents, "\n") ? "" : "\n", + e->context->marker_end); + + line = 4; /* Start editing at the contents area */ + + STRV_FOREACH(path, e->comment_paths) { + _cleanup_free_ char *comment = NULL; + + /* Skip the file which is being edited and the source file (can be the same) */ + if (PATH_IN_SET(*path, e->path, source)) + continue; + + r = read_full_file(*path, &comment, NULL); + if (r < 0) + return log_error_errno(r, "Failed to read comment file '%s': %m", *path); + + fprintf(f, "\n\n### %s", *path); + + if (!isempty(comment)) { + _cleanup_free_ char *c = NULL; + + c = strreplace(strstrip(comment), "\n", "\n# "); + if (!c) + return log_oom(); + + fprintf(f, "\n# %s", c); + } + } + } else if (source) { + r = copy_file_fd(source, fileno(f), COPY_REFLINK); + if (r < 0) { + assert(r != -ENOENT); + return log_error_errno(r, "Failed to copy file '%s' to temporary file '%s': %m", source, temp); + } + } + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write to temporary file '%s': %m", temp); + + e->temp = TAKE_PTR(temp); + e->line = line; + + return 0; +} + +static int run_editor_child(const EditFileContext *context) { + _cleanup_strv_free_ char **args = NULL; + const char *editor; + int r; + + /* SYSTEMD_EDITOR takes precedence over EDITOR which takes precedence over VISUAL. + * If neither SYSTEMD_EDITOR nor EDITOR nor VISUAL are present, we try to execute + * well known editors. */ + editor = getenv("SYSTEMD_EDITOR"); + if (!editor) + editor = getenv("EDITOR"); + if (!editor) + editor = getenv("VISUAL"); + + if (!isempty(editor)) { + _cleanup_strv_free_ char **editor_args = NULL; + + editor_args = strv_split(editor, WHITESPACE); + if (!editor_args) + return log_oom(); + + args = TAKE_PTR(editor_args); + } + + if (context->n_files == 1 && context->files[0].line > 1) { + /* If editing a single file only, use the +LINE syntax to put cursor on the right line */ + r = strv_extendf(&args, "+%u", context->files[0].line); + if (r < 0) + return log_oom(); + } + + FOREACH_ARRAY(i, context->files, context->n_files) { + r = strv_extend(&args, i->temp); + if (r < 0) + return log_oom(); + } + + if (!isempty(editor)) + execvp(args[0], (char* const*) args); + + bool prepended = false; + FOREACH_STRING(name, "editor", "nano", "vim", "vi") { + if (!prepended) { + r = strv_prepend(&args, name); + prepended = true; + } else + r = free_and_strdup(&args[0], name); + if (r < 0) + return log_oom(); + + execvp(args[0], (char* const*) args); + + /* We do not fail if the editor doesn't exist because we want to try each one of them + * before failing. */ + if (errno != ENOENT) + return log_error_errno(errno, "Failed to execute '%s': %m", name); + } + + return log_error_errno(SYNTHETIC_ERRNO(ENOENT), + "Cannot edit files, no editor available. Please set either $SYSTEMD_EDITOR, $EDITOR or $VISUAL."); +} + +static int run_editor(const EditFileContext *context) { + int r; + + assert(context); + + r = safe_fork("(editor)", FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGTERM|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG|FORK_WAIT, NULL); + if (r < 0) + return r; + if (r == 0) { /* Child */ + r = run_editor_child(context); + _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); + } + + return 0; +} + +static int strip_edit_temp_file(EditFile *e) { + _cleanup_free_ char *old_contents = NULL, *new_contents = NULL; + const char *stripped; + int r; + + assert(e); + assert(e->context); + assert(e->temp); + + r = read_full_file(e->temp, &old_contents, NULL); + if (r < 0) + return log_error_errno(r, "Failed to read temporary file '%s': %m", e->temp); + + if (e->context->marker_start) { + /* Trim out the lines between the two markers */ + char *contents_start, *contents_end; + + assert(e->context->marker_end); + + contents_start = strstrafter(old_contents, e->context->marker_start); + if (!contents_start) + contents_start = old_contents; + + contents_end = strstr(contents_start, e->context->marker_end); + if (contents_end) + *contents_end = '\0'; + + stripped = strstrip(contents_start); + } else + stripped = strstrip(old_contents); + if (isempty(stripped)) + return 0; /* File is empty (has no real changes) */ + + /* Trim prefix and suffix, but ensure suffixed by single newline */ + new_contents = strjoin(stripped, "\n"); + if (!new_contents) + return log_oom(); + + if (streq(old_contents, new_contents)) /* Don't touch the file if the above didn't change a thing */ + return 1; /* Contents unchanged after stripping but has changes */ + + r = write_string_file(e->temp, new_contents, WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_TRUNCATE | WRITE_STRING_FILE_AVOID_NEWLINE); + if (r < 0) + return log_error_errno(r, "Failed to strip temporary file '%s': %m", e->temp); + + return 1; /* Contents have real changes and are changed after stripping */ +} + +int do_edit_files_and_install(EditFileContext *context) { + int r; + + assert(context); + + if (context->n_files == 0) + return log_debug_errno(SYNTHETIC_ERRNO(ENOENT), "Got no files to edit."); + + FOREACH_ARRAY(i, context->files, context->n_files) { + r = create_edit_temp_file(i); + if (r < 0) + return r; + } + + r = run_editor(context); + if (r < 0) + return r; + + FOREACH_ARRAY(i, context->files, context->n_files) { + /* Always call strip_edit_temp_file which will tell if the temp file has actual changes */ + r = strip_edit_temp_file(i); + if (r < 0) + return r; + if (r == 0) /* temp file doesn't carry actual changes, ignoring */ + continue; + + r = RET_NERRNO(rename(i->temp, i->path)); + if (r < 0) + return log_error_errno(r, + "Failed to rename temporary file '%s' to target file '%s': %m", + i->temp, + i->path); + i->temp = mfree(i->temp); + + log_info("Successfully installed edited file '%s'.", i->path); + } + + return 0; +} |