| /* index.c: module index file shared functions for modprobe and depmod |
| Copyright (C) 2008 Alan Jenkins <alan-jenkins@tuffmail.co.uk>. |
| |
| These programs are 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 these programs. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <arpa/inet.h> /* htonl */ |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <fnmatch.h> |
| |
| #include "util.h" |
| #include "logging.h" |
| #include "index.h" |
| |
| #include "testing.h" |
| |
| /* |
| * Index abstract data type (used only by depmod) |
| */ |
| |
| struct index_node *index_create() |
| { |
| struct index_node *node; |
| |
| node = NOFAIL(calloc(sizeof(struct index_node), 1)); |
| node->prefix = NOFAIL(strdup("")); |
| node->first = INDEX_CHILDMAX; |
| |
| return node; |
| } |
| |
| void index_values_free(struct index_value *values) |
| { |
| while (values) { |
| struct index_value *value = values; |
| |
| values = value->next; |
| free(value); |
| } |
| } |
| |
| void index_destroy(struct index_node *node) |
| { |
| int c; |
| |
| for (c = node->first; c <= node->last; c++) { |
| struct index_node *child = node->children[c]; |
| |
| if (child) |
| index_destroy(child); |
| } |
| index_values_free(node->values); |
| free(node->prefix); |
| free(node); |
| } |
| |
| static void index__checkstring(const char *str) |
| { |
| int i; |
| |
| for (i = 0; str[i]; i++) { |
| int ch = str[i]; |
| |
| if (ch >= INDEX_CHILDMAX) |
| fatal("Module index: bad character '%c'=0x%x - only 7-bit ASCII is supported:" |
| "\n%s\n", (char) ch, (int) ch, str); |
| } |
| } |
| |
| static int add_value(struct index_value **values, |
| const char *value, unsigned int priority) |
| { |
| struct index_value *v; |
| int duplicate = 0; |
| int len; |
| |
| /* report the presence of duplicate values */ |
| for (v = *values; v; v = v->next) { |
| if (streq(v->value, value)) |
| duplicate = 1; |
| } |
| |
| /* find position to insert value */ |
| while (*values && (*values)->priority < priority) |
| values = &(*values)->next; |
| |
| len = strlen(value); |
| v = NOFAIL(calloc(sizeof(struct index_value) + len + 1, 1)); |
| v->next = *values; |
| v->priority = priority; |
| memcpy(v->value, value, len + 1); |
| *values = v; |
| |
| return duplicate; |
| } |
| |
| int index_insert(struct index_node *node, const char *key, |
| const char *value, unsigned int priority) |
| { |
| int i = 0; /* index within str */ |
| int ch; |
| |
| index__checkstring(key); |
| index__checkstring(value); |
| |
| while(1) { |
| int j; /* index within node->prefix */ |
| |
| /* Ensure node->prefix is a prefix of &str[i]. |
| If it is not already, then we must split node. */ |
| for (j = 0; node->prefix[j]; j++) { |
| ch = node->prefix[j]; |
| |
| if (ch != key[i+j]) { |
| char *prefix = node->prefix; |
| struct index_node *n; |
| |
| /* New child is copy of node with prefix[j+1..N] */ |
| n = NOFAIL(calloc(sizeof(struct index_node), 1)); |
| memcpy(n, node, sizeof(struct index_node)); |
| n->prefix = NOFAIL(strdup(&prefix[j+1])); |
| |
| /* Parent has prefix[0..j], child at prefix[j] */ |
| memset(node, 0, sizeof(struct index_node)); |
| prefix[j] = '\0'; |
| node->prefix = prefix; |
| node->first = ch; |
| node->last = ch; |
| node->children[ch] = n; |
| |
| break; |
| } |
| } |
| /* j is now length of node->prefix */ |
| i += j; |
| |
| ch = key[i]; |
| if(ch == '\0') |
| return add_value(&node->values, value, priority); |
| |
| if (!node->children[ch]) { |
| struct index_node *child; |
| |
| if (ch < node->first) |
| node->first = ch; |
| if (ch > node->last) |
| node->last = ch; |
| node->children[ch] = NOFAIL(calloc(sizeof(struct index_node), 1)); |
| |
| child = node->children[ch]; |
| child->prefix = NOFAIL(strdup(&key[i+1])); |
| child->first = INDEX_CHILDMAX; |
| add_value(&child->values, value, priority); |
| |
| return 0; |
| } |
| |
| /* Descend into child node and continue */ |
| node = node->children[ch]; |
| i++; |
| } |
| } |
| |
| static int index__haschildren(const struct index_node *node) |
| { |
| return node->first < INDEX_CHILDMAX; |
| } |
| |
| /* Recursive post-order traversal |
| |
| Pre-order would make for better read-side buffering / readahead / caching. |
| (post-order means you go backwards in the file as you descend the tree). |
| However, index reading is already fast enough. |
| Pre-order is simpler for writing, and depmod is already slow. |
| */ |
| static uint32_t index_write__node(const struct index_node *node, FILE *out) |
| { |
| uint32_t *child_offs = NULL; |
| int child_count = 0; |
| long offset; |
| |
| if (!node) |
| return 0; |
| |
| /* Write children and save their offsets */ |
| if (index__haschildren(node)) { |
| const struct index_node *child; |
| int i; |
| |
| child_count = node->last - node->first + 1; |
| child_offs = NOFAIL(malloc(child_count * sizeof(uint32_t))); |
| |
| for (i = 0; i < child_count; i++) { |
| child = node->children[node->first + i]; |
| child_offs[i] = htonl(index_write__node(child, out)); |
| } |
| } |
| |
| /* Now write this node */ |
| offset = ftell(out); |
| |
| if (node->prefix[0]) { |
| fputs(node->prefix, out); |
| fputc('\0', out); |
| offset |= INDEX_NODE_PREFIX; |
| } |
| |
| if (child_count) { |
| fputc(node->first, out); |
| fputc(node->last, out); |
| fwrite(child_offs, sizeof(uint32_t), child_count, out); |
| free(child_offs); |
| offset |= INDEX_NODE_CHILDS; |
| } |
| |
| if (node->values) { |
| const struct index_value *v; |
| unsigned int value_count; |
| uint32_t u; |
| |
| value_count = 0; |
| for (v = node->values; v != NULL; v = v->next) |
| value_count++; |
| u = htonl(value_count); |
| fwrite(&u, sizeof(u), 1, out); |
| |
| for (v = node->values; v != NULL; v = v->next) { |
| u = htonl(v->priority); |
| fwrite(&u, sizeof(u), 1, out); |
| fputs(v->value, out); |
| fputc('\0', out); |
| } |
| offset |= INDEX_NODE_VALUES; |
| } |
| |
| return offset; |
| } |
| |
| void index_write(const struct index_node *node, FILE *out) |
| { |
| long initial_offset, final_offset; |
| uint32_t u; |
| |
| u = htonl(INDEX_MAGIC); |
| fwrite(&u, sizeof(u), 1, out); |
| u = htonl(INDEX_VERSION); |
| fwrite(&u, sizeof(u), 1, out); |
| |
| /* Second word is reserved for the offset of the root node */ |
| initial_offset = ftell(out); |
| u = 0; |
| fwrite(&u, sizeof(uint32_t), 1, out); |
| |
| /* Dump trie */ |
| u = htonl(index_write__node(node, out)); |
| |
| /* Update first word */ |
| final_offset = ftell(out); |
| fseek(out, initial_offset, SEEK_SET); |
| fwrite(&u, sizeof(uint32_t), 1, out); |
| fseek(out, final_offset, SEEK_SET); |
| } |
| |
| |
| |
| static void read_error() |
| { |
| fatal("Module index: unexpected error: %s\n" |
| "Try re-running depmod\n", errno ? strerror(errno) : "EOF"); |
| } |
| |
| static int read_char(FILE *in) |
| { |
| int ch; |
| |
| errno = 0; |
| ch = getc_unlocked(in); |
| if (ch == EOF) |
| read_error(); |
| return ch; |
| } |
| |
| static uint32_t read_long(FILE *in) |
| { |
| uint32_t l; |
| |
| errno = 0; |
| if (fread(&l, sizeof(uint32_t), 1, in) <= 0) |
| read_error(); |
| return ntohl(l); |
| } |
| |
| /* |
| * Buffer abstract data type |
| * |
| * Used internally to store the current path during tree traversal. |
| * They help build wildcard key strings to pass to fnmatch(), |
| * as well as building values of matching keys. |
| */ |
| |
| struct buffer { |
| char *bytes; |
| unsigned size; |
| unsigned used; |
| }; |
| |
| static void buf__realloc(struct buffer *buf, unsigned size) |
| { |
| if (size > buf->size) { |
| buf->bytes = NOFAIL(realloc(buf->bytes, size)); |
| buf->size = size; |
| } |
| } |
| |
| static struct buffer *buf_create() |
| { |
| struct buffer *buf; |
| |
| buf = NOFAIL(calloc(sizeof(struct buffer), 1)); |
| buf__realloc(buf, 256); |
| return buf; |
| } |
| |
| static void buf_destroy(struct buffer *buf) |
| { |
| free(buf->bytes); |
| free(buf); |
| } |
| |
| /* Destroy buffer and return a copy as a C string */ |
| static char *buf_detach(struct buffer *buf) |
| { |
| char *bytes; |
| |
| bytes = NOFAIL(realloc(buf->bytes, buf->used + 1)); |
| bytes[buf->used] = '\0'; |
| |
| free(buf); |
| return bytes; |
| } |
| |
| /* Return a C string owned by the buffer |
| (invalidated if the buffer is changed). |
| */ |
| static const char *buf_str(struct buffer *buf) |
| { |
| buf__realloc(buf, buf->used + 1); |
| buf->bytes[buf->used] = '\0'; |
| return buf->bytes; |
| } |
| |
| static int buf_fwrite(struct buffer *buf, FILE *out) |
| { |
| return fwrite(buf->bytes, 1, buf->used, out); |
| } |
| |
| static void buf_pushchar(struct buffer *buf, char ch) |
| { |
| buf__realloc(buf, buf->used + 1); |
| buf->bytes[buf->used] = ch; |
| buf->used++; |
| } |
| |
| static unsigned buf_pushchars(struct buffer *buf, const char *str) |
| { |
| unsigned i = 0; |
| int ch; |
| |
| while ((ch = str[i])) { |
| buf_pushchar(buf, ch); |
| i++; |
| } |
| return i; |
| } |
| |
| /* like buf_pushchars(), but the string comes from a file */ |
| static unsigned buf_freadchars(struct buffer *buf, FILE *in) |
| { |
| unsigned i = 0; |
| int ch; |
| |
| while ((ch = read_char(in))) { |
| buf_pushchar(buf, ch); |
| i++; |
| } |
| |
| return i; |
| } |
| |
| static void buf_popchar(struct buffer *buf) |
| { |
| buf->used--; |
| } |
| |
| static void buf_popchars(struct buffer *buf, unsigned n) |
| { |
| buf->used -= n; |
| } |
| |
| static void buf_clear(struct buffer *buf) |
| { |
| buf->used = 0; |
| } |
| |
| /* |
| * Index file searching (used only by modprobe) |
| */ |
| |
| struct index_node_f { |
| FILE *file; |
| char *prefix; /* path compression */ |
| struct index_value *values; |
| unsigned char first; /* range of child nodes */ |
| unsigned char last; |
| uint32_t children[0]; |
| }; |
| |
| static struct index_node_f *index_read(FILE *in, uint32_t offset) |
| { |
| struct index_node_f *node; |
| char *prefix; |
| int i, child_count = 0; |
| |
| if ((offset & INDEX_NODE_MASK) == 0) |
| return NULL; |
| |
| fseek(in, offset & INDEX_NODE_MASK, SEEK_SET); |
| |
| if (offset & INDEX_NODE_PREFIX) { |
| struct buffer *buf = buf_create(); |
| buf_freadchars(buf, in); |
| prefix = buf_detach(buf); |
| } else |
| prefix = NOFAIL(strdup("")); |
| |
| if (offset & INDEX_NODE_CHILDS) { |
| char first = read_char(in); |
| char last = read_char(in); |
| child_count = last - first + 1; |
| |
| node = NOFAIL(malloc(sizeof(struct index_node_f) + |
| sizeof(uint32_t) * child_count)); |
| |
| node->first = first; |
| node->last = last; |
| |
| for (i = 0; i < child_count; i++) |
| node->children[i] = read_long(in); |
| } else { |
| node = NOFAIL(malloc(sizeof(struct index_node_f))); |
| node->first = INDEX_CHILDMAX; |
| node->last = 0; |
| } |
| |
| node->values = NULL; |
| if (offset & INDEX_NODE_VALUES) { |
| int value_count; |
| struct buffer *buf = buf_create(); |
| const char *value; |
| unsigned int priority; |
| |
| value_count = read_long(in); |
| |
| while (value_count--) { |
| priority = read_long(in); |
| buf_freadchars(buf, in); |
| value = buf_str(buf); |
| add_value(&node->values, value, priority); |
| buf_clear(buf); |
| } |
| buf_destroy(buf); |
| } |
| |
| node->prefix = prefix; |
| node->file = in; |
| return node; |
| } |
| |
| static void index_close(struct index_node_f *node) |
| { |
| free(node->prefix); |
| index_values_free(node->values); |
| free(node); |
| } |
| |
| struct index_file { |
| FILE *file; |
| uint32_t root_offset; |
| }; |
| |
| /* Failures are silent; modprobe will fall back to text files */ |
| struct index_file *index_file_open(const char *filename) |
| { |
| FILE *file; |
| uint32_t magic, version; |
| struct index_file *new; |
| |
| file = fopen(filename, "r"); |
| if (!file) |
| return NULL; |
| errno = EINVAL; |
| |
| magic = read_long(file); |
| if (magic != INDEX_MAGIC) |
| return NULL; |
| |
| version = read_long(file); |
| if (version >> 16 != INDEX_VERSION_MAJOR) |
| return NULL; |
| |
| new = NOFAIL(malloc(sizeof(struct index_file))); |
| new->file = file; |
| new->root_offset = read_long(new->file); |
| |
| errno = 0; |
| return new; |
| } |
| |
| void index_file_close(struct index_file *index) |
| { |
| fclose(index->file); |
| free(index); |
| } |
| |
| |
| static struct index_node_f *index_readroot(struct index_file *in) |
| { |
| return index_read(in->file, in->root_offset); |
| } |
| |
| static struct index_node_f *index_readchild(const struct index_node_f *parent, |
| int ch) |
| { |
| if (parent->first <= ch && ch <= parent->last) |
| return index_read(parent->file, |
| parent->children[ch - parent->first]); |
| else |
| return NULL; |
| } |
| |
| /* |
| * Dump all strings as lines in a plain text file. |
| */ |
| |
| static void index_dump_node(struct index_node_f *node, |
| struct buffer *buf, |
| FILE *out, |
| const char *prefix) |
| { |
| struct index_value *v; |
| int ch, pushed; |
| |
| pushed = buf_pushchars(buf, node->prefix); |
| |
| for (v = node->values; v != NULL; v = v->next) { |
| fputs(prefix, out); |
| buf_fwrite(buf, out); |
| fputc(' ', out); |
| fputs(v->value, out); |
| fputc('\n', out); |
| } |
| |
| for (ch = node->first; ch <= node->last; ch++) { |
| struct index_node_f *child = index_readchild(node, ch); |
| |
| if (!child) |
| continue; |
| |
| buf_pushchar(buf, ch); |
| index_dump_node(child, buf, out, prefix); |
| buf_popchar(buf); |
| } |
| |
| buf_popchars(buf, pushed); |
| index_close(node); |
| } |
| |
| void index_dump(struct index_file *in, FILE *out, const char *prefix) |
| { |
| struct index_node_f *root; |
| struct buffer *buf; |
| |
| buf = buf_create(); |
| root = index_readroot(in); |
| index_dump_node(root, buf, out, prefix); |
| buf_destroy(buf); |
| } |
| |
| /* |
| * Search the index for a key |
| * |
| * Returns the value of the first match |
| * |
| * The recursive functions free their node argument (using index_close). |
| */ |
| |
| char *index_search(struct index_file *in, const char *key); |
| static char *index_search__node(struct index_node_f *node, const char *key, int i); |
| |
| char *index_search(struct index_file *in, const char *key) |
| { |
| struct index_node_f *root; |
| char *value; |
| |
| root = index_readroot(in); |
| value = index_search__node(root, key, 0); |
| |
| return value; |
| } |
| |
| static char *index_search__node(struct index_node_f *node, const char *key, int i) |
| { |
| char *value; |
| struct index_node_f *child; |
| int ch; |
| int j; |
| |
| while(node) { |
| for (j = 0; node->prefix[j]; j++) { |
| ch = node->prefix[j]; |
| |
| if (ch != key[i+j]) { |
| index_close(node); |
| return NULL; |
| } |
| } |
| i += j; |
| |
| if (key[i] == '\0') { |
| if (node->values) { |
| value = strdup(node->values[0].value); |
| index_close(node); |
| return value; |
| } else { |
| return NULL; |
| } |
| } |
| |
| child = index_readchild(node, key[i]); |
| index_close(node); |
| node = child; |
| i++; |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * Search the index for a key. The index may contain wildcards. |
| * |
| * Returns a list of all the values of matching keys. |
| */ |
| |
| /* Level 1: interface function */ |
| struct index_value *index_searchwild(struct index_file *in, const char *key); |
| |
| /* Level 2: descend the tree (until we hit a wildcard) */ |
| static void index_searchwild__node(struct index_node_f *node, |
| struct buffer *buf, |
| const char *key, int i, |
| struct index_value **out); |
| |
| /* Level 3: traverse a sub-keyspace which starts with a wildcard, |
| looking for matches. |
| */ |
| static void index_searchwild__all(struct index_node_f *node, int j, |
| struct buffer *buf, |
| const char *subkey, |
| struct index_value **out); |
| |
| /* Level 4: add all the values from a matching node */ |
| static void index_searchwild__allvalues(struct index_node_f *node, |
| struct index_value **out); |
| |
| |
| struct index_value *index_searchwild(struct index_file *in, const char *key) |
| { |
| struct index_node_f *root = index_readroot(in); |
| struct buffer *buf = buf_create(); |
| struct index_value *out = NULL; |
| |
| index_searchwild__node(root, buf, key, 0, &out); |
| buf_destroy(buf); |
| return out; |
| } |
| |
| static void index_searchwild__node(struct index_node_f *node, |
| struct buffer *buf, |
| const char *key, int i, |
| struct index_value **out) |
| { |
| struct index_node_f *child; |
| int j; |
| int ch; |
| |
| while(node) { |
| for (j = 0; node->prefix[j]; j++) { |
| ch = node->prefix[j]; |
| |
| if (ch == '*' || ch == '?' || ch == '[') { |
| index_searchwild__all(node, j, buf, |
| &key[i+j], out); |
| return; |
| } |
| |
| if (ch != key[i+j]) { |
| index_close(node); |
| return; |
| } |
| } |
| i += j; |
| |
| child = index_readchild(node, '*'); |
| if (child) { |
| buf_pushchar(buf, '*'); |
| index_searchwild__all(child, 0, buf, &key[i], out); |
| buf_popchar(buf); |
| } |
| |
| child = index_readchild(node, '?'); |
| if (child) { |
| buf_pushchar(buf, '?'); |
| index_searchwild__all(child, 0, buf, &key[i], out); |
| buf_popchar(buf); |
| } |
| |
| child = index_readchild(node, '['); |
| if (child) { |
| buf_pushchar(buf, '['); |
| index_searchwild__all(child, 0, buf, &key[i], out); |
| buf_popchar(buf); |
| } |
| |
| if (key[i] == '\0') { |
| index_searchwild__allvalues(node, out); |
| |
| return; |
| } |
| |
| child = index_readchild(node, key[i]); |
| index_close(node); |
| node = child; |
| i++; |
| } |
| } |
| |
| static void index_searchwild__all(struct index_node_f *node, int j, |
| struct buffer *buf, |
| const char *subkey, |
| struct index_value **out) |
| { |
| int pushed = 0; |
| int ch; |
| |
| while (node->prefix[j]) { |
| ch = node->prefix[j]; |
| |
| buf_pushchar(buf, ch); |
| pushed++; |
| j++; |
| } |
| |
| for (ch = node->first; ch <= node->last; ch++) { |
| struct index_node_f *child = index_readchild(node, ch); |
| |
| if (!child) |
| continue; |
| |
| buf_pushchar(buf, ch); |
| index_searchwild__all(child, 0, buf, subkey, out); |
| buf_popchar(buf); |
| } |
| |
| if (node->values) { |
| if (fnmatch(buf_str(buf), subkey, 0) == 0) |
| index_searchwild__allvalues(node, out); |
| } else { |
| index_close(node); |
| } |
| |
| buf_popchars(buf, pushed); |
| } |
| |
| static void index_searchwild__allvalues(struct index_node_f *node, |
| struct index_value **out) |
| { |
| struct index_value *v; |
| |
| for (v = node->values; v != NULL; v = v->next) |
| add_value(out, v->value, v->priority); |
| |
| index_close(node); |
| } |