+/*
+ * open a stream and go to the right position
+ *
+ * note: when opening for write and seeking to the beginning of
+ * the stream, truncate the file
+ */
+static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write)
+{
+ FILE *file = NULL;
+ int fd, ret;
+
+ fd = open(filename, (write ? O_RDWR | O_CREAT : O_RDONLY));
+ if (fd <= 0)
+ goto error;
+
+ if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
+ goto error;
+
+ if (write && (pos == SEEK_SET))
+ ret = ftruncate(fd, 0);
+ else
+ ret = lseek(fd, 0, pos);
+
+ if (ret < 0)
+ goto error;
+
+ file = fdopen(fd, (write ? "w" : "r"));
+ if (file)
+ goto done;
+
+error:
+ UCI_THROW(ctx, UCI_ERR_IO);
+done:
+ return file;
+}
+
+static void uci_close_stream(FILE *stream)
+{
+ int fd;
+
+ if (!stream)
+ return;
+
+ fd = fileno(stream);
+ flock(fd, LOCK_UN);
+ fclose(stream);
+}
+
+static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
+{
+ bool delete = false;
+ char *package = NULL;
+ char *section = NULL;
+ char *option = NULL;
+ char *value = NULL;
+
+ if (buf[0] == '-') {
+ delete = true;
+ buf++;
+ }
+
+ UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, §ion, &option, &value);
+ if (!package || !section || !value)
+ goto error;
+ if (strcmp(package, p->e.name) != 0)
+ goto error;
+ if (!uci_validate_name(section))
+ goto error;
+ if (option && !uci_validate_name(option))
+ goto error;
+ if (!delete)
+ UCI_INTERNAL(uci_set, ctx, package, section, option, value);
+ return;
+
+error:
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+}
+
+static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
+{
+ struct uci_parse_context *pctx;
+
+ /* make sure no memory from previous parse attempts is leaked */
+ uci_file_cleanup(ctx);
+
+ pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
+ ctx->pctx = pctx;
+ pctx->file = stream;
+
+ rewind(stream);
+ while (!feof(pctx->file)) {
+ uci_getln(ctx, 0);
+ if (!pctx->buf[0])
+ continue;
+ uci_parse_history_line(ctx, p, pctx->buf);
+ }
+
+ /* no error happened, we can get rid of the parser context now */
+ uci_file_cleanup(ctx);
+}
+
+static void uci_load_history(struct uci_context *ctx, struct uci_package *p)
+{
+ char *filename;
+ FILE *f = NULL;
+
+ if (!p->confdir)
+ return;
+ if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
+ UCI_THROW(ctx, UCI_ERR_MEM);
+
+ UCI_TRAP_SAVE(ctx, done);
+ f = uci_open_stream(ctx, filename, SEEK_SET, false);
+ uci_parse_history(ctx, f, p);
+ UCI_TRAP_RESTORE(ctx);
+done:
+ uci_close_stream(f);
+ ctx->errno = 0;
+}
+