diff options
Diffstat (limited to 'utils')
| -rw-r--r-- | utils/Makefile.am | 6 | ||||
| -rw-r--r-- | utils/osmo-config-merge.c | 266 |
2 files changed, 271 insertions, 1 deletions
diff --git a/utils/Makefile.am b/utils/Makefile.am index d4999bde..fb791906 100644 --- a/utils/Makefile.am +++ b/utils/Makefile.am @@ -5,12 +5,16 @@ LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/src/gsm/libosmogsm.la EXTRA_DIST = conv_gen.py conv_codes_gsm.py -bin_PROGRAMS = osmo-arfcn osmo-auc-gen +bin_PROGRAMS = osmo-arfcn osmo-auc-gen osmo-config-merge osmo_arfcn_SOURCES = osmo-arfcn.c osmo_auc_gen_SOURCES = osmo-auc-gen.c +osmo_config_merge_SOURCES = osmo-config-merge.c +osmo_config_merge_LDADD = $(LDADD) $(TALLOC_LIBS) +osmo_config_merge_CFLAGS = $(TALLOC_CFLAGS) + if ENABLE_PCSC noinst_PROGRAMS = osmo-sim-test osmo_sim_test_SOURCES = osmo-sim-test.c diff --git a/utils/osmo-config-merge.c b/utils/osmo-config-merge.c new file mode 100644 index 00000000..131486c1 --- /dev/null +++ b/utils/osmo-config-merge.c @@ -0,0 +1,266 @@ +/*! \file osmo-config-merge.c + * Utility program for merging config files with patches */ +/* + * (C) 2018 by Harald Welte <laforge@gnumonks.org> + * + * All Rights Reserved + * + * This program 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 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +/* + This utility allows you to merge an incremental config "patch" + into an osmocom-style config file. + + The patch file follows the same syntax as the original config file. + + It works by appending the leaf nodes of the patch file to the respective + nodes of the input config file. + + This process allows configuration file changes/updates to be performed + in a more stable/reliable way than by means of [unified] diff files, + as they break every time the context lines break. + + osmo-config-merge doesn't suffer from this problem, as it understands + the tree-like nature of VTY config files. + + NITE: This only works with configuration files that have proper + indenting, i.e. every level in the hierarchy must be indented excatly + one character, not multiple. + */ + +#include <stdio.h> +#include <string.h> + +#include <osmocom/core/linuxlist.h> +#include <osmocom/core/talloc.h> +#include <osmocom/core/utils.h> + +struct node { + struct node *parent; /* back-pointer */ + struct llist_head list; /* part of parent->children */ + struct llist_head children; /* our own children */ + char *line; +}; + +/* allocate a new node */ +static struct node *node_alloc(void *ctx) +{ + struct node *node = talloc_zero(ctx, struct node); + OSMO_ASSERT(node); + INIT_LLIST_HEAD(&node->children); + return node; +} + +/* allocate a new node as child of given parent */ +static struct node *node_alloc_child(struct node *parent) +{ + struct node *node = node_alloc(parent); + node->parent = parent; + llist_add_tail(&node->list, &parent->children); + return node; +} + +/* find a given child specified by name/line string within given parent */ +static struct node *node_find_child(struct node *parent, const char *line) +{ + struct node *n; + + llist_for_each_entry(n, &parent->children, list) { + if (!strcmp(line, n->line)) + return n; + } + return NULL; +} + +/* count the number of spaces / indent level */ +static int count_indent(const char *line) +{ + int i; + + for (i = 0; i < strlen(line); i++) { + if (line[i] != ' ') + return i; + } + return i; +} + +/* strip any triling CR / LF */ +static void chomp(char *line) +{ + while (1) { + int len = strlen(line); + if (len == 0) + return; + char *lastch = &line[len-1]; + switch (*lastch) { + case '\n': + case '\r': + *lastch = '\0'; + default: + return; + } + } +} + +/* read a config file and parse it into a tree of nodes */ +static struct node *file_read(void *ctx, const char *fname) +{ + struct node *root, *last; + FILE *infile; + char line[1024]; + int cur_indent = -1; + unsigned int line_num = 0; + + infile = fopen(fname, "r"); + if (!infile) + return NULL; + + root = node_alloc(ctx); + last = root; + while (fgets(line, sizeof(line), infile)) { + line_num++; + chomp(line); + int indent = count_indent(line); + struct node *n; + if (indent > cur_indent) { + if (indent > cur_indent+1) { + fprintf(stderr, "File '%s' isn't well-formed in line %u, aborting!\n", + fname, line_num); + exit(2); + } + /* new child to last node */ + n = node_alloc_child(last); + } else if (indent < cur_indent) { + for (int i = 0; i < cur_indent - indent; i++) { + /* go to parent, add another sibling */ + if (last->parent) + last = last->parent; + } + n = node_alloc_child(last->parent); + } else { + /* add a new sibling (child of parent) */ + n = node_alloc_child(last->parent); + } + n->line = talloc_strdup(n, line); + + last = n; + cur_indent = indent; + } + + return root; +} + +static void append_patch(struct node *cfg, struct node *patch) +{ + struct node *n; + + llist_for_each_entry(n, &patch->children, list) { + if (llist_empty(&n->children)) { + struct node *t; + /* we are an end-node, i.e. something that needs to be + * patched into the original tree. We do this by simply + * appending it to the list of siblings */ + t = node_alloc_child(cfg); + t->line = talloc_strdup(t, n->line); + } else { + struct node *c; + /* we need to iterate / recurse further */ + + /* try to find the matching original node */ + c = node_find_child(cfg, n->line); + if (!c) { + /* create it, if it's missing */ + c = node_alloc_child(cfg); + c->line = talloc_strdup(c, n->line); + } + append_patch(c, n); + } + } +} + + +static int level = -1; + +static void dump_node(struct node *root, FILE *out, bool print_node_depth) +{ + struct node *n; + level++; + + if (root->line) { + if (print_node_depth) { + for (int i = 0; i < level; i++) + fputc('*', out); + } + + fprintf(out, "%s\n", root->line); + } + + llist_for_each_entry(n, &root->children, list) { + dump_node(n, out, print_node_depth); + } + level--; +} + +static void exit_usage(int rc) +{ + fprintf(stderr, "Usage: osmo-config-merge <config-file> <config-patch> [--debug]\n"); + exit(rc); +} + + +int main(int argc, char **argv) +{ + const char *base_fname, *patch_fname; + struct node *base_tree, *patch_tree; + bool debug_enabled = false; + + void *ctx = talloc_named_const(NULL, 0, "root"); + + if (argc < 3) + exit_usage(1); + + base_fname = argv[1]; + patch_fname = argv[2]; + + if (argc > 3) { + if (!strcmp(argv[3], "--debug")) + debug_enabled = true; + else + exit_usage(1); + } + + base_tree = file_read(ctx, base_fname); + patch_tree = file_read(ctx, patch_fname); + + if (debug_enabled) { + fprintf(stderr, "====== dumping tree (base)\n"); + dump_node(base_tree, stderr, true); + fprintf(stderr, "====== dumping tree (patch)\n"); + dump_node(patch_tree, stderr, true); + } + + append_patch(base_tree, patch_tree); + + if (debug_enabled) + fprintf(stderr, "====== dumping tree (patched)\n"); + dump_node(base_tree, stdout, false); + fflush(stdout); + + /* make AddressSanitizer / LeakSanitizer happy by recursively freeing the trees */ + talloc_free(patch_tree); + talloc_free(base_tree); +} |