libcutils/dir_hash.c - android-core - Git at Google

 /*
  * Copyright (C) 2007 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <dirent.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sha1.h>
 #include <unistd.h>
 #include <limits.h>

 #include <sys/stat.h>

 #include <netinet/in.h>
 #include <resolv.h>

 #include <cutils/dir_hash.h>

 /**
  * Copies, if it fits within max_output_string bytes, into output_string
  * a hash of the contents, size, permissions, uid, and gid of the file
  * specified by path, using the specified algorithm.  Returns the length
  * of the output string, or a negative number if the buffer is too short.
  */
 int get_file_hash(HashAlgorithm algorithm, const char *path,
                   char *output_string, size_t max_output_string) {
     SHA1_CTX context;
     struct stat sb;
     unsigned char md[SHA1_DIGEST_LENGTH];
     int used;
     size_t n;

     if (algorithm != SHA_1) {
         errno = EINVAL;
         return -1;
     }

     if (stat(path, &sb) != 0) {
         return -1;
     }

     if (S_ISLNK(sb.st_mode)) {
         char buf[PATH_MAX];
         int len;

         len = readlink(path, buf, sizeof(buf));
         if (len < 0) {
             return -1;
         }

         SHA1Init(&context);
         SHA1Update(&context, (unsigned char *) buf, len);
         SHA1Final(md, &context);
     } else if (S_ISREG(sb.st_mode)) {
         char buf[10000];
         FILE *f = fopen(path, "rb");
         int len;

         if (f == NULL) {
             return -1;
         }

         SHA1Init(&context);

         while ((len = fread(buf, 1, sizeof(buf), f)) > 0) {
             SHA1Update(&context, (unsigned char *) buf, len);
         }

         if (ferror(f)) {
             fclose(f);
             return -1;
         }

         fclose(f);
         SHA1Final(md, &context);
     }

     if (S_ISLNK(sb.st_mode) || S_ISREG(sb.st_mode)) {
         used = b64_ntop(md, SHA1_DIGEST_LENGTH,
                         output_string, max_output_string);
         if (used < 0) {
             errno = ENOSPC;
             return -1;
         }

         n = snprintf(output_string + used, max_output_string - used,
                      " %d 0%o %d %d", (int) sb.st_size, sb.st_mode,
                      (int) sb.st_uid, (int) sb.st_gid);
     } else {
         n = snprintf(output_string, max_output_string,
                      "- - 0%o %d %d", sb.st_mode,
                      (int) sb.st_uid, (int) sb.st_gid);
     }

     if (n >= max_output_string - used) {
         errno = ENOSPC;
         return -(used + n);
     }

     return used + n;
 }

 struct list {
     char *name;
     struct list *next;
 };

 static int cmp(const void *a, const void *b) {
     struct list *const *ra = a;
     struct list *const *rb = b;

     return strcmp((*ra)->name, (*rb)->name);
 }

 static int recurse(HashAlgorithm algorithm, const char *directory_path,
                     struct list **out) {
     struct list *list = NULL;
     struct list *f;

     struct dirent *de;
     DIR *d = opendir(directory_path);

     if (d == NULL) {
         return -1;
     }

     while ((de = readdir(d)) != NULL) {
         if (strcmp(de->d_name, ".") == 0) {
             continue;
         }
         if (strcmp(de->d_name, "..") == 0) {
             continue;
         }

         char *name = malloc(strlen(de->d_name) + 1);
         struct list *node = malloc(sizeof(struct list));

         if (name == NULL || node == NULL) {
             struct list *next;
             for (f = list; f != NULL; f = next) {
                 next = f->next;
                 free(f->name);
                 free(f);
             }

             free(name);
             free(node);
             return -1;
         }

         strcpy(name, de->d_name);

         node->name = name;
         node->next = list;
         list = node;
     }

     closedir(d);

     for (f = list; f != NULL; f = f->next) {
         struct stat sb;
         char *name;
         char outstr[NAME_MAX + 100];
         char *keep;
         struct list *res;

         name = malloc(strlen(f->name) + strlen(directory_path) + 2);
         if (name == NULL) {
             struct list *next;
             for (f = list; f != NULL; f = f->next) {
                 next = f->next;
                 free(f->name);
                 free(f);
             }
             for (f = *out; f != NULL; f = f->next) {
                 next = f->next;
                 free(f->name);
                 free(f);
             }
             *out = NULL;
             return -1;
         }

         sprintf(name, "%s/%s", directory_path, f->name);

         int len = get_file_hash(algorithm, name,
                                 outstr, sizeof(outstr));
         if (len < 0) {
             // should not happen
             return -1;
         }

         keep = malloc(len + strlen(name) + 3);
         res = malloc(sizeof(struct list));

         if (keep == NULL || res == NULL) {
             struct list *next;
             for (f = list; f != NULL; f = f->next) {
                 next = f->next;
                 free(f->name);
                 free(f);
             }
             for (f = *out; f != NULL; f = f->next) {
                 next = f->next;
                 free(f->name);
                 free(f);
             }
             *out = NULL;

             free(keep);
             free(res);
             return -1;
         }

         sprintf(keep, "%s %s\n", name, outstr);

         res->name = keep;
         res->next = *out;
         *out = res;

         if ((stat(name, &sb) == 0) && S_ISDIR(sb.st_mode)) {
             if (recurse(algorithm, name, out) < 0) {
                 struct list *next;
                 for (f = list; f != NULL; f = next) {
                     next = f->next;
                     free(f->name);
                     free(f);
                 }

                 return -1;
             }
         }
     }

     struct list *next;
     for (f = list; f != NULL; f = next) {
         next = f->next;

         free(f->name);
         free(f);
     }
 }

 /**
  * Allocates a string containing the names and hashes of all files recursively
  * reached under the specified directory_path, using the specified algorithm.
  * The string is returned as *output_string; the return value is the length
  * of the string, or a negative number if there was a failure.
  */
 int get_recursive_hash_manifest(HashAlgorithm algorithm,
                                 const char *directory_path,
                                 char **output_string) {
     struct list *out = NULL;
     struct list *r;
     struct list **list;
     int count = 0;
     int len = 0;
     int retlen = 0;
     int i;
     char *buf;

     if (recurse(algorithm, directory_path, &out) < 0) {
         return -1;
     }

     for (r = out; r != NULL; r = r->next) {
         count++;
         len += strlen(r->name);
     }

     list = malloc(count * sizeof(struct list *));
     if (list == NULL) {
         struct list *next;
         for (r = out; r != NULL; r = next) {
             next = r->next;
             free(r->name);
             free(r);
         }
         return -1;
     }

     count = 0;
     for (r = out; r != NULL; r = r->next) {
         list[count++] = r;
     }

     qsort(list, count, sizeof(struct list *), cmp);

     buf = malloc(len + 1);
     if (buf == NULL) {
         struct list *next;
         for (r = out; r != NULL; r = next) {
             next = r->next;
             free(r->name);
             free(r);
         }
         free(list);
         return -1;
     }

     for (i = 0; i < count; i++) {
         int n = strlen(list[i]->name);

         strcpy(buf + retlen, list[i]->name);
         retlen += n;
     }

     free(list);

     struct list *next;
     for (r = out; r != NULL; r = next) {
         next = r->next;

         free(r->name);
         free(r);
     }

     *output_string = buf;
     return retlen;
 }
	/*
	* Copyright (C) 2007 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <dirent.h>
	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sha1.h>
	#include <unistd.h>
	#include <limits.h>

	#include <sys/stat.h>

	#include <netinet/in.h>
	#include <resolv.h>

	#include <cutils/dir_hash.h>

	/**
	* Copies, if it fits within max_output_string bytes, into output_string
	* a hash of the contents, size, permissions, uid, and gid of the file
	* specified by path, using the specified algorithm. Returns the length
	* of the output string, or a negative number if the buffer is too short.
	*/
	int get_file_hash(HashAlgorithm algorithm, const char *path,
	char *output_string, size_t max_output_string) {
	SHA1_CTX context;
	struct stat sb;
	unsigned char md[SHA1_DIGEST_LENGTH];
	int used;
	size_t n;

	if (algorithm != SHA_1) {
	errno = EINVAL;
	return -1;
	}

	if (stat(path, &sb) != 0) {
	return -1;
	}

	if (S_ISLNK(sb.st_mode)) {
	char buf[PATH_MAX];
	int len;

	len = readlink(path, buf, sizeof(buf));
	if (len < 0) {
	return -1;
	}

	SHA1Init(&context);
	SHA1Update(&context, (unsigned char *) buf, len);
	SHA1Final(md, &context);
	} else if (S_ISREG(sb.st_mode)) {
	char buf[10000];
	FILE *f = fopen(path, "rb");
	int len;

	if (f == NULL) {
	return -1;
	}

	SHA1Init(&context);

	while ((len = fread(buf, 1, sizeof(buf), f)) > 0) {
	SHA1Update(&context, (unsigned char *) buf, len);
	}

	if (ferror(f)) {
	fclose(f);
	return -1;
	}

	fclose(f);
	SHA1Final(md, &context);
	}

	if (S_ISLNK(sb.st_mode) \|\| S_ISREG(sb.st_mode)) {
	used = b64_ntop(md, SHA1_DIGEST_LENGTH,
	output_string, max_output_string);
	if (used < 0) {
	errno = ENOSPC;
	return -1;
	}

	n = snprintf(output_string + used, max_output_string - used,
	" %d 0%o %d %d", (int) sb.st_size, sb.st_mode,
	(int) sb.st_uid, (int) sb.st_gid);
	} else {
	n = snprintf(output_string, max_output_string,
	"- - 0%o %d %d", sb.st_mode,
	(int) sb.st_uid, (int) sb.st_gid);
	}

	if (n >= max_output_string - used) {
	errno = ENOSPC;
	return -(used + n);
	}

	return used + n;
	}

	struct list {
	char *name;
	struct list *next;
	};

	static int cmp(const void a, const void b) {
	struct list const ra = a;
	struct list const rb = b;

	return strcmp((ra)->name, (rb)->name);
	}

	static int recurse(HashAlgorithm algorithm, const char *directory_path,
	struct list **out) {
	struct list *list = NULL;
	struct list *f;

	struct dirent *de;
	DIR *d = opendir(directory_path);

	if (d == NULL) {
	return -1;
	}

	while ((de = readdir(d)) != NULL) {
	if (strcmp(de->d_name, ".") == 0) {
	continue;
	}
	if (strcmp(de->d_name, "..") == 0) {
	continue;
	}

	char *name = malloc(strlen(de->d_name) + 1);
	struct list *node = malloc(sizeof(struct list));

	if (name == NULL \|\| node == NULL) {
	struct list *next;
	for (f = list; f != NULL; f = next) {
	next = f->next;
	free(f->name);
	free(f);
	}

	free(name);
	free(node);
	return -1;
	}

	strcpy(name, de->d_name);

	node->name = name;
	node->next = list;
	list = node;
	}

	closedir(d);

	for (f = list; f != NULL; f = f->next) {
	struct stat sb;
	char *name;
	char outstr[NAME_MAX + 100];
	char *keep;
	struct list *res;

	name = malloc(strlen(f->name) + strlen(directory_path) + 2);
	if (name == NULL) {
	struct list *next;
	for (f = list; f != NULL; f = f->next) {
	next = f->next;
	free(f->name);
	free(f);
	}
	for (f = *out; f != NULL; f = f->next) {
	next = f->next;
	free(f->name);
	free(f);
	}
	*out = NULL;
	return -1;
	}

	sprintf(name, "%s/%s", directory_path, f->name);

	int len = get_file_hash(algorithm, name,
	outstr, sizeof(outstr));
	if (len < 0) {
	// should not happen
	return -1;
	}

	keep = malloc(len + strlen(name) + 3);
	res = malloc(sizeof(struct list));

	if (keep == NULL \|\| res == NULL) {
	struct list *next;
	for (f = list; f != NULL; f = f->next) {
	next = f->next;
	free(f->name);
	free(f);
	}
	for (f = *out; f != NULL; f = f->next) {
	next = f->next;
	free(f->name);
	free(f);
	}
	*out = NULL;

	free(keep);
	free(res);
	return -1;
	}

	sprintf(keep, "%s %s\n", name, outstr);

	res->name = keep;
	res->next = *out;
	*out = res;

	if ((stat(name, &sb) == 0) && S_ISDIR(sb.st_mode)) {
	if (recurse(algorithm, name, out) < 0) {
	struct list *next;
	for (f = list; f != NULL; f = next) {
	next = f->next;
	free(f->name);
	free(f);
	}

	return -1;
	}
	}
	}

	struct list *next;
	for (f = list; f != NULL; f = next) {
	next = f->next;

	free(f->name);
	free(f);
	}
	}

	/**
	* Allocates a string containing the names and hashes of all files recursively
	* reached under the specified directory_path, using the specified algorithm.
	* The string is returned as *output_string; the return value is the length
	* of the string, or a negative number if there was a failure.
	*/
	int get_recursive_hash_manifest(HashAlgorithm algorithm,
	const char *directory_path,
	char **output_string) {
	struct list *out = NULL;
	struct list *r;
	struct list **list;
	int count = 0;
	int len = 0;
	int retlen = 0;
	int i;
	char *buf;

	if (recurse(algorithm, directory_path, &out) < 0) {
	return -1;
	}

	for (r = out; r != NULL; r = r->next) {
	count++;
	len += strlen(r->name);
	}

	list = malloc(count * sizeof(struct list *));
	if (list == NULL) {
	struct list *next;
	for (r = out; r != NULL; r = next) {
	next = r->next;
	free(r->name);
	free(r);
	}
	return -1;
	}

	count = 0;
	for (r = out; r != NULL; r = r->next) {
	list[count++] = r;
	}

	qsort(list, count, sizeof(struct list *), cmp);

	buf = malloc(len + 1);
	if (buf == NULL) {
	struct list *next;
	for (r = out; r != NULL; r = next) {
	next = r->next;
	free(r->name);
	free(r);
	}
	free(list);
	return -1;
	}

	for (i = 0; i < count; i++) {
	int n = strlen(list[i]->name);

	strcpy(buf + retlen, list[i]->name);
	retlen += n;
	}

	free(list);

	struct list *next;
	for (r = out; r != NULL; r = next) {
	next = r->next;

	free(r->name);
	free(r);
	}

	*output_string = buf;
	return retlen;
	}