/* * libuci - Library for the Unified Configuration Interface * Copyright (C) 2008 Felix Fietkau * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1 * as published by the Free Software Foundation * * This program 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 Lesser General Public License for more details. */ /* * This file contains the code for parsing uci config files */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include "uci.h" #include "uci_internal.h" #define LINEBUF 32 /* * Fetch a new line from the input stream and resize buffer if necessary */ __private void uci_getln(struct uci_context *ctx, int offset) { struct uci_parse_context *pctx = ctx->pctx; char *p; int ofs; if (pctx->buf == NULL) { pctx->buf = uci_malloc(ctx, LINEBUF); pctx->bufsz = LINEBUF; } /* It takes 2 slots for fgets to read 1 char. */ if (offset >= pctx->bufsz - 1) { pctx->bufsz *= 2; pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz); } ofs = offset; do { p = &pctx->buf[ofs]; p[0] = 0; p = fgets(p, pctx->bufsz - ofs, pctx->file); if (!p || !*p) return; ofs += strlen(p); pctx->buf_filled = ofs; if (pctx->buf[ofs - 1] == '\n') { pctx->line++; return; } pctx->bufsz *= 2; pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz); } while (1); } /* * parse a character escaped by '\' * returns true if the escaped character is to be parsed * returns false if the escaped character is to be ignored */ static bool parse_backslash(struct uci_context *ctx) { struct uci_parse_context *pctx = ctx->pctx; /* skip backslash */ pctx->pos += 1; /* undecoded backslash at the end of line, fetch the next line */ if (!pctx_cur_char(pctx) || pctx_cur_char(pctx) == '\n' || (pctx_cur_char(pctx) == '\r' && pctx_char(pctx, pctx_pos(pctx) + 1) == '\n' && !pctx_char(pctx, pctx_pos(pctx) + 2))) { uci_getln(ctx, pctx->pos); return false; } /* FIXME: decode escaped char, necessary? */ return true; } /* * move the string pointer forward until a non-whitespace character or * EOL is reached */ static void skip_whitespace(struct uci_context *ctx) { struct uci_parse_context *pctx = ctx->pctx; while (pctx_cur_char(pctx) && isspace(pctx_cur_char(pctx))) pctx->pos += 1; } static inline void addc(struct uci_context *ctx, int *pos_dest, int *pos_src) { struct uci_parse_context *pctx = ctx->pctx; pctx_char(pctx, *pos_dest) = pctx_char(pctx, *pos_src); *pos_dest += 1; *pos_src += 1; } static int uci_increase_pos(struct uci_parse_context *pctx, size_t add) { if (pctx->pos + add > pctx->buf_filled) return -EINVAL; pctx->pos += add; return 0; } /* * parse a double quoted string argument from the command line */ static void parse_double_quote(struct uci_context *ctx, int *target) { struct uci_parse_context *pctx = ctx->pctx; char c; /* skip quote character */ pctx->pos += 1; while (1) { c = pctx_cur_char(pctx); switch(c) { case '"': pctx->pos += 1; return; case 0: /* Multi-line str value */ uci_getln(ctx, pctx->pos); if (!pctx_cur_char(pctx)) { uci_parse_error(ctx, "EOF with unterminated \""); } break; case '\\': if (!parse_backslash(ctx)) continue; /* fall through */ default: addc(ctx, target, &pctx->pos); break; } } } /* * parse a single quoted string argument from the command line */ static void parse_single_quote(struct uci_context *ctx, int *target) { struct uci_parse_context *pctx = ctx->pctx; char c; /* skip quote character */ pctx->pos += 1; while (1) { c = pctx_cur_char(pctx); switch(c) { case '\'': pctx->pos += 1; return; case 0: /* Multi-line str value */ uci_getln(ctx, pctx->pos); if (!pctx_cur_char(pctx)) uci_parse_error(ctx, "EOF with unterminated '"); break; default: addc(ctx, target, &pctx->pos); } } } /* * parse a string from the command line and detect the quoting style */ static void parse_str(struct uci_context *ctx, int *target) { struct uci_parse_context *pctx = ctx->pctx; bool next = true; do { switch(pctx_cur_char(pctx)) { case '\'': parse_single_quote(ctx, target); break; case '"': parse_double_quote(ctx, target); break; case '#': pctx_cur_char(pctx) = 0; /* fall through */ case 0: goto done; case ';': next = false; goto done; case '\\': if (!parse_backslash(ctx)) continue; /* fall through */ default: addc(ctx, target, &pctx->pos); break; } } while (pctx_cur_char(pctx) && !isspace(pctx_cur_char(pctx))); done: /* * if the string was unquoted and we've stopped at a whitespace * character, skip to the next one, because the whitespace will * be overwritten by a null byte here */ if (pctx_cur_char(pctx) && next) pctx->pos += 1; /* terminate the parsed string */ pctx_char(pctx, *target) = 0; } /* * extract the next argument from the command line */ static int next_arg(struct uci_context *ctx, bool required, bool name, bool package) { struct uci_parse_context *pctx = ctx->pctx; int val, ptr; skip_whitespace(ctx); val = ptr = pctx_pos(pctx); if (pctx_cur_char(pctx) == ';') { pctx_cur_char(pctx) = 0; pctx->pos += 1; } else { parse_str(ctx, &ptr); } if (!pctx_char(pctx, val)) { if (required) uci_parse_error(ctx, "insufficient arguments"); goto done; } if (name && !uci_validate_str(pctx_str(pctx, val), name, package)) uci_parse_error(ctx, "invalid character in name field"); done: return val; } int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result) { int ofs_result; UCI_HANDLE_ERR(ctx); UCI_ASSERT(ctx, str != NULL); UCI_ASSERT(ctx, result != NULL); if (ctx->pctx && (ctx->pctx->file != stream)) uci_cleanup(ctx); if (!ctx->pctx) uci_alloc_parse_context(ctx); ctx->pctx->file = stream; if (!*str) { ctx->pctx->pos = 0; uci_getln(ctx, 0); } ofs_result = next_arg(ctx, false, false, false); *result = pctx_str(ctx->pctx, ofs_result); *str = pctx_cur_str(ctx->pctx); return 0; } static int uci_fill_ptr(struct uci_context *ctx, struct uci_ptr *ptr, struct uci_element *e) { UCI_ASSERT(ctx, ptr != NULL); UCI_ASSERT(ctx, e != NULL); memset(ptr, 0, sizeof(struct uci_ptr)); switch(e->type) { case UCI_TYPE_OPTION: ptr->o = uci_to_option(e); goto fill_option; case UCI_TYPE_SECTION: ptr->s = uci_to_section(e); goto fill_section; case UCI_TYPE_PACKAGE: ptr->p = uci_to_package(e); goto fill_package; default: UCI_THROW(ctx, UCI_ERR_INVAL); } fill_option: ptr->option = ptr->o->e.name; ptr->s = ptr->o->section; fill_section: ptr->section = ptr->s->e.name; ptr->p = ptr->s->package; fill_package: ptr->package = ptr->p->e.name; ptr->flags |= UCI_LOOKUP_DONE; return 0; } /* * verify that the end of the line or command is reached. * throw an error if extra arguments are given on the command line */ static void assert_eol(struct uci_context *ctx) { char *tmp; int ofs_tmp; skip_whitespace(ctx); ofs_tmp = next_arg(ctx, false, false, false); tmp = pctx_str(ctx->pctx, ofs_tmp); if (*tmp && (ctx->flags & UCI_FLAG_STRICT)) uci_parse_error(ctx, "too many arguments"); } /* * switch to a different config, either triggered by uci_load, or by a * 'package <...>' statement in the import file */ static void uci_switch_config(struct uci_context *ctx) { struct uci_parse_context *pctx; struct uci_element *e; const char *name; pctx = ctx->pctx; name = pctx->name; /* add the last config to main config file list */ if (pctx->package) { pctx->package->backend = ctx->backend; uci_list_add(&ctx->root, &pctx->package->e.list); pctx->package = NULL; pctx->section = NULL; } if (!name) return; /* * if an older config under the same name exists, unload it * ignore errors here, e.g. if the config was not found */ e = uci_lookup_list(&ctx->root, name); if (e) UCI_THROW(ctx, UCI_ERR_DUPLICATE); pctx->package = uci_alloc_package(ctx, name); } /* * parse the 'package' uci command (next config package) */ static void uci_parse_package(struct uci_context *ctx, bool single) { struct uci_parse_context *pctx = ctx->pctx; int ofs_name; char *name; /* command string null-terminated by strtok */ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1)) uci_parse_error(ctx, "package without name"); ofs_name = next_arg(ctx, true, true, true); assert_eol(ctx); name = pctx_str(pctx, ofs_name); if (single) return; ctx->pctx->name = name; uci_switch_config(ctx); } /* * parse the 'config' uci command (open a section) */ static void uci_parse_config(struct uci_context *ctx) { struct uci_parse_context *pctx = ctx->pctx; struct uci_element *e; struct uci_ptr ptr; int ofs_name, ofs_type; char *name; char *type; if (!ctx->pctx->package) { if (!ctx->pctx->name) uci_parse_error(ctx, "attempting to import a file without a package name"); uci_switch_config(ctx); } /* command string null-terminated by strtok */ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1)) uci_parse_error(ctx, "config without name"); ofs_type = next_arg(ctx, true, false, false); type = pctx_str(pctx, ofs_type); if (!uci_validate_type(type)) uci_parse_error(ctx, "invalid character in type field"); ofs_name = next_arg(ctx, false, true, false); type = pctx_str(pctx, ofs_type); name = pctx_str(pctx, ofs_name); assert_eol(ctx); if (!name || !name[0]) { ctx->internal = !pctx->merge; UCI_NESTED(uci_add_section, ctx, pctx->package, type, &pctx->section); } else { uci_fill_ptr(ctx, &ptr, &pctx->package->e); e = uci_lookup_list(&pctx->package->sections, name); if (e) { ptr.s = uci_to_section(e); if ((ctx->flags & UCI_FLAG_STRICT) && strcmp(ptr.s->type, type)) uci_parse_error(ctx, "section of different type overwrites prior section with same name"); } ptr.section = name; ptr.value = type; ctx->internal = !pctx->merge; UCI_NESTED(uci_set, ctx, &ptr); pctx->section = uci_to_section(ptr.last); } } /* * parse the 'option' uci command (open a value) */ static void uci_parse_option(struct uci_context *ctx, bool list) { struct uci_parse_context *pctx = ctx->pctx; struct uci_element *e; struct uci_ptr ptr; int ofs_name, ofs_value; char *name = NULL; char *value = NULL; if (!pctx->section) uci_parse_error(ctx, "option/list command found before the first section"); /* command string null-terminated by strtok */ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1)) uci_parse_error(ctx, "option without name"); ofs_name = next_arg(ctx, true, true, false); ofs_value = next_arg(ctx, false, false, false); name = pctx_str(pctx, ofs_name); value = pctx_str(pctx, ofs_value); assert_eol(ctx); uci_fill_ptr(ctx, &ptr, &pctx->section->e); e = uci_lookup_list(&pctx->section->options, name); if (e) ptr.o = uci_to_option(e); ptr.option = name; ptr.value = value; ctx->internal = !pctx->merge; if (list) UCI_NESTED(uci_add_list, ctx, &ptr); else UCI_NESTED(uci_set, ctx, &ptr); } /* * parse a complete input line, split up combined commands by ';' */ static void uci_parse_line(struct uci_context *ctx, bool single) { struct uci_parse_context *pctx = ctx->pctx; char *word; /* Skip whitespace characters at the start of line */ skip_whitespace(ctx); do { word = strtok(pctx_cur_str(pctx), " \t"); if (!word) return; switch(word[0]) { case 0: case '#': return; case 'p': if ((word[1] == 0) || !strcmp(word + 1, "ackage")) uci_parse_package(ctx, single); else goto invalid; break; case 'c': if ((word[1] == 0) || !strcmp(word + 1, "onfig")) uci_parse_config(ctx); else goto invalid; break; case 'o': if ((word[1] == 0) || !strcmp(word + 1, "ption")) uci_parse_option(ctx, false); else goto invalid; break; case 'l': if ((word[1] == 0) || !strcmp(word + 1, "ist")) uci_parse_option(ctx, true); else goto invalid; break; default: goto invalid; } continue; invalid: uci_parse_error(ctx, "invalid command"); } while (1); } /* max number of characters that escaping adds to the string */ #define UCI_QUOTE_ESCAPE "'\\''" /* * escape an uci string for export */ static const char *uci_escape(struct uci_context *ctx, const char *str) { const char *end; int ofs = 0; if (!ctx->buf) { ctx->bufsz = LINEBUF; ctx->buf = malloc(LINEBUF); if (!ctx->buf) return str; } while (1) { int len; end = strchr(str, '\''); if (!end) end = str + strlen(str); len = end - str; /* make sure that we have enough room in the buffer */ while (ofs + len + sizeof(UCI_QUOTE_ESCAPE) + 1 > ctx->bufsz) { ctx->bufsz *= 2; ctx->buf = uci_realloc(ctx, ctx->buf, ctx->bufsz); } /* copy the string until the character before the quote */ memcpy(&ctx->buf[ofs], str, len); ofs += len; /* end of string? return the buffer */ if (*end == 0) break; memcpy(&ctx->buf[ofs], UCI_QUOTE_ESCAPE, sizeof(UCI_QUOTE_ESCAPE)); ofs += strlen(&ctx->buf[ofs]); str = end + 1; } ctx->buf[ofs] = 0; return ctx->buf; } /* * export a single config package to a file stream */ static void uci_export_package(struct uci_package *p, FILE *stream, bool header) { struct uci_context *ctx = p->ctx; struct uci_element *s, *o, *i; if (header) fprintf(stream, "package %s\n", uci_escape(ctx, p->e.name)); uci_foreach_element(&p->sections, s) { struct uci_section *sec = uci_to_section(s); fprintf(stream, "\nconfig %s", uci_escape(ctx, sec->type)); if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME)) fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name)); fprintf(stream, "\n"); uci_foreach_element(&sec->options, o) { struct uci_option *opt = uci_to_option(o); switch(opt->type) { case UCI_TYPE_STRING: fprintf(stream, "\toption %s", uci_escape(ctx, opt->e.name)); fprintf(stream, " '%s'\n", uci_escape(ctx, opt->v.string)); break; case UCI_TYPE_LIST: uci_foreach_element(&opt->v.list, i) { fprintf(stream, "\tlist %s", uci_escape(ctx, opt->e.name)); fprintf(stream, " '%s'\n", uci_escape(ctx, i->name)); } break; default: fprintf(stream, "\t# unknown type for option '%s'\n", uci_escape(ctx, opt->e.name)); break; } } } fprintf(stream, "\n"); } int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header) { struct uci_element *e; UCI_HANDLE_ERR(ctx); UCI_ASSERT(ctx, stream != NULL); if (package) uci_export_package(package, stream, header); else { uci_foreach_element(&ctx->root, e) { uci_export_package(uci_to_package(e), stream, header); } } return 0; } int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single) { struct uci_parse_context *pctx; UCI_HANDLE_ERR(ctx); /* make sure no memory from previous parse attempts is leaked */ uci_cleanup(ctx); uci_alloc_parse_context(ctx); pctx = ctx->pctx; pctx->file = stream; if (package && *package && single) { pctx->package = *package; pctx->merge = true; } /* * If 'name' was supplied, assume that the supplied stream does not contain * the appropriate 'package ' string to specify the config name * NB: the config file can still override the package name */ if (name) { UCI_ASSERT(ctx, uci_validate_package(name)); pctx->name = name; } while (!feof(pctx->file)) { pctx->pos = 0; uci_getln(ctx, 0); UCI_TRAP_SAVE(ctx, error); if (pctx->buf[0]) uci_parse_line(ctx, single); UCI_TRAP_RESTORE(ctx); continue; error: if (ctx->flags & UCI_FLAG_PERROR) uci_perror(ctx, NULL); if ((ctx->err != UCI_ERR_PARSE) || (ctx->flags & UCI_FLAG_STRICT)) UCI_THROW(ctx, ctx->err); } if (!pctx->package && name) uci_switch_config(ctx); if (package) *package = pctx->package; if (pctx->merge) pctx->package = NULL; pctx->name = NULL; uci_switch_config(ctx); /* no error happened, we can get rid of the parser context now */ uci_cleanup(ctx); return 0; } static char *uci_config_path(struct uci_context *ctx, const char *name) { char *filename; UCI_ASSERT(ctx, uci_validate_package(name)); filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2); sprintf(filename, "%s/%s", ctx->confdir, name); return filename; } static void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite) { struct uci_package *p = *package; FILE *f1, *f2 = NULL; char *name = NULL; char *path = NULL; char *filename = NULL; bool do_rename = false; int fd; if (!p->path) { if (overwrite) p->path = uci_config_path(ctx, p->e.name); else UCI_THROW(ctx, UCI_ERR_INVAL); } if ((asprintf(&filename, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name) < 0) || !filename) UCI_THROW(ctx, UCI_ERR_MEM); /* open the config file for writing now, so that it is locked */ f1 = uci_open_stream(ctx, p->path, NULL, SEEK_SET, true, true); /* flush unsaved changes and reload from delta file */ UCI_TRAP_SAVE(ctx, done); if (p->has_delta) { if (!overwrite) { name = uci_strdup(ctx, p->e.name); path = uci_strdup(ctx, p->path); /* dump our own changes to the delta file */ if (!uci_list_empty(&p->delta)) UCI_INTERNAL(uci_save, ctx, p); /* * other processes might have modified the config * as well. dump and reload */ uci_free_package(&p); uci_cleanup(ctx); UCI_INTERNAL(uci_import, ctx, f1, name, &p, true); p->path = path; p->has_delta = true; *package = p; /* freed together with the uci_package */ path = NULL; } /* flush delta */ if (!uci_load_delta(ctx, p, true)) goto done; } fd = mkstemp(filename); if (fd == -1) UCI_THROW(ctx, UCI_ERR_IO); if ((flock(fd, LOCK_EX) < 0) && (errno != ENOSYS)) UCI_THROW(ctx, UCI_ERR_IO); if (lseek(fd, 0, SEEK_SET) < 0) UCI_THROW(ctx, UCI_ERR_IO); f2 = fdopen(fd, "w+"); if (!f2) UCI_THROW(ctx, UCI_ERR_IO); uci_export(ctx, f2, p, false); fflush(f2); fsync(fileno(f2)); uci_close_stream(f2); do_rename = true; UCI_TRAP_RESTORE(ctx); done: free(name); free(path); uci_close_stream(f1); if (do_rename) { path = realpath(p->path, NULL); if (!path || rename(filename, path)) { unlink(filename); UCI_THROW(ctx, UCI_ERR_IO); } free(path); } free(filename); if (ctx->err) UCI_THROW(ctx, ctx->err); } /* * This function returns the filename by returning the string * after the last '/' character. By checking for a non-'\0' * character afterwards, directories are ignored (glob marks * those with a trailing '/' */ static inline char *get_filename(char *path) { char *p; p = strrchr(path, '/'); p++; if (!*p) return NULL; return p; } static char **uci_list_config_files(struct uci_context *ctx) { char **configs; glob_t globbuf; int size, i, j, skipped; char *buf; char *dir; dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*")); sprintf(dir, "%s/*", ctx->confdir); if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0) { free(dir); UCI_THROW(ctx, UCI_ERR_NOTFOUND); } size = sizeof(char *) * (globbuf.gl_pathc + 1); skipped = 0; for(i = 0; i < globbuf.gl_pathc; i++) { char *p; p = get_filename(globbuf.gl_pathv[i]); if (!p) { skipped++; continue; } size += strlen(p) + 1; } configs = uci_malloc(ctx, size - skipped); buf = (char *) &configs[globbuf.gl_pathc + 1 - skipped]; j = 0; for(i = 0; i < globbuf.gl_pathc; i++) { char *p; p = get_filename(globbuf.gl_pathv[i]); if (!p) continue; if (!uci_validate_package(p)) continue; configs[j++] = buf; strcpy(buf, p); buf += strlen(buf) + 1; } free(dir); globfree(&globbuf); return configs; } static struct uci_package *uci_file_load(struct uci_context *ctx, const char *name) { struct uci_package *package = NULL; char *filename; bool confdir; FILE *file = NULL; switch (name[0]) { case '.': /* relative path outside of /etc/config */ if (name[1] != '/') UCI_THROW(ctx, UCI_ERR_NOTFOUND); /* fall through */ case '/': /* absolute path outside of /etc/config */ filename = uci_strdup(ctx, name); name = strrchr(name, '/') + 1; confdir = false; break; default: /* config in /etc/config */ filename = uci_config_path(ctx, name); confdir = true; break; } UCI_TRAP_SAVE(ctx, done); file = uci_open_stream(ctx, filename, NULL, SEEK_SET, false, false); ctx->err = 0; UCI_INTERNAL(uci_import, ctx, file, name, &package, true); UCI_TRAP_RESTORE(ctx); if (package) { package->path = filename; package->has_delta = confdir; uci_load_delta(ctx, package, false); } done: uci_close_stream(file); if (ctx->err) { free(filename); UCI_THROW(ctx, ctx->err); } return package; } __private UCI_BACKEND(uci_file_backend, "file", .load = uci_file_load, .commit = uci_file_commit, .list_configs = uci_list_config_files, );