Remove usages of alpm_list_next() in backend

[pacman-ng.git] / lib / libalpm / util.c

/*
 *  util.c
 *
 *  Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
 *  Copyright (c) 2006 by David Kimpe <dnaku@frugalware.org>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <time.h>
#include <syslog.h>
#include <errno.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <locale.h> /* setlocale */

/* libarchive */
#include <archive.h>
#include <archive_entry.h>

#ifdef HAVE_LIBSSL
#include <openssl/md5.h>
#include <openssl/sha.h>
#else
#include "md5.h"
#include "sha2.h"
#endif

/* libalpm */
#include "util.h"
#include "log.h"
#include "alpm.h"
#include "alpm_list.h"
#include "handle.h"
#include "trans.h"

#ifndef HAVE_STRSEP
/* This is a replacement for strsep which is not portable (missing on Solaris).
 * Copyright (c) 2001 by François Gouget <fgouget_at_codeweavers.com> */
char* strsep(char** str, const char* delims)
{
        char* token;

        if(*str==NULL) {
                /* No more tokens */
                return NULL;
        }

        token=*str;
        while(**str!='\0') {
                if(strchr(delims,**str)!=NULL) {
                        **str='\0';
                        (*str)++;
                        return token;
                }
                (*str)++;
        }
        /* There is no other token */
        *str=NULL;
        return token;
}
#endif

int _alpm_makepath(const char *path)
{
        return _alpm_makepath_mode(path, 0755);
}

/* does the same thing as 'mkdir -p' */
int _alpm_makepath_mode(const char *path, mode_t mode)
{
        /* A bit of pointer hell here. Descriptions:
         * orig - a copy of path so we can safely butcher it with strsep
         * str - the current position in the path string (after the delimiter)
         * ptr - the original position of str after calling strsep
         * incr - incrementally generated path for use in stat/mkdir call
         */
        char *orig, *str, *ptr, *incr;
        mode_t oldmask = umask(0000);
        int ret = 0;

        orig = strdup(path);
        incr = calloc(strlen(orig) + 1, sizeof(char));
        str = orig;
        while((ptr = strsep(&str, "/"))) {
                if(strlen(ptr)) {
                        /* we have another path component- append the newest component to
                         * existing string and create one more level of dir structure */
                        strcat(incr, "/");
                        strcat(incr, ptr);
                        if(access(incr, F_OK)) {
                                if(mkdir(incr, mode)) {
                                        ret = 1;
                                        break;
                                }
                        }
                }
        }
        free(orig);
        free(incr);
        umask(oldmask);
        return ret;
}

#define CPBUFSIZE 8 * 1024

int _alpm_copyfile(const char *src, const char *dest)
{
        FILE *in, *out;
        size_t len;
        char *buf;
        int ret = 0;

        in = fopen(src, "rb");
        if(in == NULL) {
                return 1;
        }
        out = fopen(dest, "wb");
        if(out == NULL) {
                fclose(in);
                return 1;
        }

        CALLOC(buf, (size_t)CPBUFSIZE, (size_t)1, ret = 1; goto cleanup;);

        /* do the actual file copy */
        while((len = fread(buf, 1, CPBUFSIZE, in))) {
                size_t nwritten = 0;
                nwritten = fwrite(buf, 1, len, out);
                if((nwritten != len) || ferror(out)) {
                        ret = -1;
                        goto cleanup;
                }
        }

        /* chmod dest to permissions of src, as long as it is not a symlink */
        struct stat statbuf;
        if(!stat(src, &statbuf)) {
                if(! S_ISLNK(statbuf.st_mode)) {
                        fchmod(fileno(out), statbuf.st_mode);
                }
        } else {
                /* stat was unsuccessful */
                ret = 1;
        }

cleanup:
        fclose(in);
        fclose(out);
        FREE(buf);
        return ret;
}

/* Trim whitespace and newlines from a string
*/
char *_alpm_strtrim(char *str)
{
        char *pch = str;

        if(*str == '\0') {
                /* string is empty, so we're done. */
                return str;
        }

        while(isspace((unsigned char)*pch)) {
                pch++;
        }
        if(pch != str) {
                memmove(str, pch, (strlen(pch) + 1));
        }

        /* check if there wasn't anything but whitespace in the string. */
        if(*str == '\0') {
                return str;
        }

        pch = (str + (strlen(str) - 1));
        while(isspace((unsigned char)*pch)) {
                pch--;
        }
        *++pch = '\0';

        return str;
}

/**
 * Trim trailing newline from a string (if one exists).
 * @param str a single line of text
 * @return the length of the trimmed string
 */
size_t _alpm_strip_newline(char *str)
{
        size_t len;
        if(str == '\0') {
                return 0;
        }
        len = strlen(str);
        while(len > 0 && str[len - 1] == '\n') {
                len--;
        }
        str[len] = '\0';

        return len;
}

/* Compression functions */

/**
 * @brief Unpack a specific file in an archive.
 *
 * @param handle the context handle
 * @param archive the archive to unpack
 * @param prefix where to extract the files
 * @param filename a file within the archive to unpack
 * @return 0 on success, 1 on failure
 */
int _alpm_unpack_single(alpm_handle_t *handle, const char *archive,
                const char *prefix, const char *filename)
{
        alpm_list_t *list = NULL;
        int ret = 0;
        if(filename == NULL) {
                return 1;
        }
        list = alpm_list_add(list, (void *)filename);
        ret = _alpm_unpack(handle, archive, prefix, list, 1);
        alpm_list_free(list);
        return ret;
}

/**
 * @brief Unpack a list of files in an archive.
 *
 * @param handle the context handle
 * @param archive the archive to unpack
 * @param prefix where to extract the files
 * @param list a list of files within the archive to unpack or NULL for all
 * @param breakfirst break after the first entry found
 *
 * @return 0 on success, 1 on failure
 */
int _alpm_unpack(alpm_handle_t *handle, const char *archive, const char *prefix,
                alpm_list_t *list, int breakfirst)
{
        int ret = 0;
        mode_t oldmask;
        struct archive *_archive;
        struct archive_entry *entry;
        char cwd[PATH_MAX];
        int restore_cwd = 0;

        if((_archive = archive_read_new()) == NULL) {
                RET_ERR(handle, ALPM_ERR_LIBARCHIVE, 1);
        }

        archive_read_support_compression_all(_archive);
        archive_read_support_format_all(_archive);

        if(archive_read_open_filename(_archive, archive,
                                ARCHIVE_DEFAULT_BYTES_PER_BLOCK) != ARCHIVE_OK) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not open file %s: %s\n"), archive,
                                archive_error_string(_archive));
                RET_ERR(handle, ALPM_ERR_PKG_OPEN, 1);
        }

        oldmask = umask(0022);

        /* save the cwd so we can restore it later */
        if(getcwd(cwd, PATH_MAX) == NULL) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not get current working directory\n"));
        } else {
                restore_cwd = 1;
        }

        /* just in case our cwd was removed in the upgrade operation */
        if(chdir(prefix) != 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not change directory to %s (%s)\n"),
                                prefix, strerror(errno));
                ret = 1;
                goto cleanup;
        }

        while(archive_read_next_header(_archive, &entry) == ARCHIVE_OK) {
                const struct stat *st;
                const char *entryname; /* the name of the file in the archive */

                st = archive_entry_stat(entry);
                entryname = archive_entry_pathname(entry);

                if(S_ISREG(st->st_mode)) {
                        archive_entry_set_perm(entry, 0644);
                } else if(S_ISDIR(st->st_mode)) {
                        archive_entry_set_perm(entry, 0755);
                }

                /* If specific files were requested, skip entries that don't match. */
                if(list) {
                        char *entry_prefix = strdup(entryname);
                        char *p = strstr(entry_prefix,"/");
                        if(p) {
                                *(p+1) = '\0';
                        }
                        char *found = alpm_list_find_str(list, entry_prefix);
                        free(entry_prefix);
                        if(!found) {
                                if(archive_read_data_skip(_archive) != ARCHIVE_OK) {
                                        ret = 1;
                                        goto cleanup;
                                }
                                continue;
                        } else {
                                _alpm_log(handle, ALPM_LOG_DEBUG, "extracting: %s\n", entryname);
                        }
                }

                /* Extract the archive entry. */
                int readret = archive_read_extract(_archive, entry, 0);
                if(readret == ARCHIVE_WARN) {
                        /* operation succeeded but a non-critical error was encountered */
                        _alpm_log(handle, ALPM_LOG_WARNING, _("warning given when extracting %s (%s)\n"),
                                        entryname, archive_error_string(_archive));
                } else if(readret != ARCHIVE_OK) {
                        _alpm_log(handle, ALPM_LOG_ERROR, _("could not extract %s (%s)\n"),
                                        entryname, archive_error_string(_archive));
                        ret = 1;
                        goto cleanup;
                }

                if(breakfirst) {
                        break;
                }
        }

cleanup:
        umask(oldmask);
        archive_read_finish(_archive);
        if(restore_cwd && chdir(cwd) != 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not change directory to %s (%s)\n"),
                                cwd, strerror(errno));
        }
        return ret;
}

/* does the same thing as 'rm -rf' */
int _alpm_rmrf(const char *path)
{
        int errflag = 0;
        struct dirent *dp;
        DIR *dirp;
        char name[PATH_MAX];
        struct stat st;

        if(_alpm_lstat(path, &st) == 0) {
                if(!S_ISDIR(st.st_mode)) {
                        if(!unlink(path)) {
                                return 0;
                        } else {
                                if(errno == ENOENT) {
                                        return 0;
                                } else {
                                        return 1;
                                }
                        }
                } else {
                        dirp = opendir(path);
                        if(!dirp) {
                                return 1;
                        }
                        for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) {
                                if(dp->d_ino) {
                                        sprintf(name, "%s/%s", path, dp->d_name);
                                        if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) {
                                                errflag += _alpm_rmrf(name);
                                        }
                                }
                        }
                        closedir(dirp);
                        if(rmdir(path)) {
                                errflag++;
                        }
                }
                return errflag;
        }
        return 0;
}

/**
 * Determine if there are files in a directory
 * @param handle the context handle
 * @param path the full absolute directory path
 * @param full_count whether to return an exact count of files
 * @return a file count if full_count is != 0, else >0 if directory has
 * contents, 0 if no contents, and -1 on error
 */
ssize_t _alpm_files_in_directory(alpm_handle_t *handle, const char *path,
                int full_count)
{
        ssize_t files = 0;
        struct dirent *ent;
        DIR *dir = opendir(path);

        if(!dir) {
                if(errno == ENOTDIR) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "%s was not a directory\n", path);
                } else {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "could not read directory %s\n",
                                        path);
                }
                return -1;
        }
        while((ent = readdir(dir)) != NULL) {
                const char *name = ent->d_name;

                if(strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
                        continue;
                }

                files++;

                if(!full_count) {
                        break;
                }
        }

        closedir(dir);
        return files;
}

int _alpm_logaction(alpm_handle_t *handle, const char *fmt, va_list args)
{
        int ret = 0;

        if(handle->usesyslog) {
                /* we can't use a va_list more than once, so we need to copy it
                 * so we can use the original when calling vfprintf below. */
                va_list args_syslog;
                va_copy(args_syslog, args);
                vsyslog(LOG_WARNING, fmt, args_syslog);
                va_end(args_syslog);
        }

        if(handle->logstream) {
                time_t t;
                struct tm *tm;

                t = time(NULL);
                tm = localtime(&t);

                /* Use ISO-8601 date format */
                fprintf(handle->logstream, "[%04d-%02d-%02d %02d:%02d] ",
                                                tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
                                                tm->tm_hour, tm->tm_min);
                ret = vfprintf(handle->logstream, fmt, args);
                fflush(handle->logstream);
        }

        return ret;
}

int _alpm_run_chroot(alpm_handle_t *handle, const char *path, char *const argv[])
{
        char cwd[PATH_MAX];
        pid_t pid;
        int pipefd[2];
        int restore_cwd = 0;
        int retval = 0;

        /* save the cwd so we can restore it later */
        if(getcwd(cwd, PATH_MAX) == NULL) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not get current working directory\n"));
        } else {
                restore_cwd = 1;
        }

        /* just in case our cwd was removed in the upgrade operation */
        if(chdir(handle->root) != 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not change directory to %s (%s)\n"),
                                handle->root, strerror(errno));
                goto cleanup;
        }

        _alpm_log(handle, ALPM_LOG_DEBUG, "executing \"%s\" under chroot \"%s\"\n",
                        path, handle->root);

        /* Flush open fds before fork() to avoid cloning buffers */
        fflush(NULL);

        if(pipe(pipefd) == -1) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not create pipe (%s)\n"), strerror(errno));
                retval = 1;
                goto cleanup;
        }

        /* fork- parent and child each have seperate code blocks below */
        pid = fork();
        if(pid == -1) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not fork a new process (%s)\n"), strerror(errno));
                retval = 1;
                goto cleanup;
        }

        if(pid == 0) {
                /* this code runs for the child only (the actual chroot/exec) */
                close(1);
                close(2);
                while(dup2(pipefd[1], 1) == -1 && errno == EINTR);
                while(dup2(pipefd[1], 2) == -1 && errno == EINTR);
                close(pipefd[0]);
                close(pipefd[1]);

                /* use fprintf instead of _alpm_log to send output through the parent */
                if(chroot(handle->root) != 0) {
                        fprintf(stderr, _("could not change the root directory (%s)\n"), strerror(errno));
                        exit(1);
                }
                if(chdir("/") != 0) {
                        fprintf(stderr, _("could not change directory to %s (%s)\n"),
                                        "/", strerror(errno));
                        exit(1);
                }
                umask(0022);
                execv(path, argv);
                fprintf(stderr, _("call to execv failed (%s)\n"), strerror(errno));
                exit(1);
        } else {
                /* this code runs for the parent only (wait on the child) */
                int status;
                FILE *pipe_file;

                close(pipefd[1]);
                pipe_file = fdopen(pipefd[0], "r");
                if(pipe_file == NULL) {
                        close(pipefd[0]);
                        retval = 1;
                } else {
                        while(!feof(pipe_file)) {
                                char line[PATH_MAX];
                                if(fgets(line, PATH_MAX, pipe_file) == NULL)
                                        break;
                                alpm_logaction(handle, "%s", line);
                                EVENT(handle->trans, ALPM_TRANS_EVT_SCRIPTLET_INFO, line, NULL);
                        }
                        fclose(pipe_file);
                }

                while(waitpid(pid, &status, 0) == -1) {
                        if(errno != EINTR) {
                                _alpm_log(handle, ALPM_LOG_ERROR, _("call to waitpid failed (%s)\n"), strerror(errno));
                                retval = 1;
                                goto cleanup;
                        }
                }

                /* report error from above after the child has exited */
                if(retval != 0) {
                        _alpm_log(handle, ALPM_LOG_ERROR, _("could not open pipe (%s)\n"), strerror(errno));
                        goto cleanup;
                }
                /* check the return status, make sure it is 0 (success) */
                if(WIFEXITED(status)) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "call to waitpid succeeded\n");
                        if(WEXITSTATUS(status) != 0) {
                                _alpm_log(handle, ALPM_LOG_ERROR, _("command failed to execute correctly\n"));
                                retval = 1;
                        }
                }
        }

cleanup:
        if(restore_cwd && chdir(cwd) != 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not change directory to %s (%s)\n"), cwd, strerror(errno));
        }

        return retval;
}

int _alpm_ldconfig(alpm_handle_t *handle)
{
        char line[PATH_MAX];

        _alpm_log(handle, ALPM_LOG_DEBUG, "running ldconfig\n");

        snprintf(line, PATH_MAX, "%setc/ld.so.conf", handle->root);
        if(access(line, F_OK) == 0) {
                snprintf(line, PATH_MAX, "%ssbin/ldconfig", handle->root);
                if(access(line, X_OK) == 0) {
                        char *argv[] = { "ldconfig", NULL };
                        _alpm_run_chroot(handle, "/sbin/ldconfig", argv);
                }
        }

        return 0;
}

/* Helper function for comparing strings using the
 * alpm "compare func" signature */
int _alpm_str_cmp(const void *s1, const void *s2)
{
        return strcmp(s1, s2);
}

/** Find a filename in a registered alpm cachedir.
 * @param handle the context handle
 * @param filename name of file to find
 * @return malloced path of file, NULL if not found
 */
char *_alpm_filecache_find(alpm_handle_t *handle, const char *filename)
{
        char path[PATH_MAX];
        char *retpath;
        alpm_list_t *i;
        struct stat buf;

        /* Loop through the cache dirs until we find a matching file */
        for(i = alpm_option_get_cachedirs(handle); i; i = i->next) {
                snprintf(path, PATH_MAX, "%s%s", (char *)alpm_list_getdata(i),
                                filename);
                if(stat(path, &buf) == 0 && S_ISREG(buf.st_mode)) {
                        retpath = strdup(path);
                        _alpm_log(handle, ALPM_LOG_DEBUG, "found cached pkg: %s\n", retpath);
                        return retpath;
                }
        }
        /* package wasn't found in any cachedir */
        return NULL;
}

/** Check the alpm cachedirs for existance and find a writable one.
 * If no valid cache directory can be found, use /tmp.
 * @param handle the context handle
 * @return pointer to a writable cache directory.
 */
const char *_alpm_filecache_setup(alpm_handle_t *handle)
{
        struct stat buf;
        alpm_list_t *i, *tmp;
        char *cachedir;

        /* Loop through the cache dirs until we find a writeable dir */
        for(i = alpm_option_get_cachedirs(handle); i; i = i->next) {
                cachedir = alpm_list_getdata(i);
                if(stat(cachedir, &buf) != 0) {
                        /* cache directory does not exist.... try creating it */
                        _alpm_log(handle, ALPM_LOG_WARNING, _("no %s cache exists, creating...\n"),
                                        cachedir);
                        if(_alpm_makepath(cachedir) == 0) {
                                _alpm_log(handle, ALPM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
                                return cachedir;
                        }
                } else if(S_ISDIR(buf.st_mode) && (buf.st_mode & S_IWUSR)) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
                        return cachedir;
                } else {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "skipping cachedir: %s\n", cachedir);
                }
        }

        /* we didn't find a valid cache directory. use /tmp. */
        tmp = alpm_list_add(NULL, "/tmp/");
        alpm_option_set_cachedirs(handle, tmp);
        alpm_list_free(tmp);
        _alpm_log(handle, ALPM_LOG_DEBUG, "using cachedir: %s\n", "/tmp/");
        _alpm_log(handle, ALPM_LOG_WARNING, _("couldn't create package cache, using /tmp instead\n"));
        return "/tmp/";
}

/** lstat wrapper that treats /path/dirsymlink/ the same as /path/dirsymlink.
 * Linux lstat follows POSIX semantics and still performs a dereference on
 * the first, and for uses of lstat in libalpm this is not what we want.
 * @param path path to file to lstat
 * @param buf structure to fill with stat information
 * @return the return code from lstat
 */
int _alpm_lstat(const char *path, struct stat *buf)
{
        int ret;
        size_t len = strlen(path);

        /* strip the trailing slash if one exists */
        if(len != 0 && path[len - 1] == '/') {
                char *newpath = strdup(path);
                newpath[len - 1] = '\0';
                ret = lstat(newpath, buf);
                free(newpath);
        } else {
                ret = lstat(path, buf);
        }

        return ret;
}

#ifdef HAVE_LIBSSL
static int md5_file(const char *path, unsigned char output[16])
{
        FILE *f;
        size_t n;
        MD5_CTX ctx;
        unsigned char *buf;

        CALLOC(buf, 8192, sizeof(unsigned char), return 1);

        if((f = fopen(path, "rb")) == NULL) {
                free(buf);
                return 1;
        }

        MD5_Init(&ctx);

        while((n = fread(buf, 1, sizeof(buf), f)) > 0) {
                MD5_Update(&ctx, buf, n);
        }

        MD5_Final(output, &ctx);

        memset(&ctx, 0, sizeof(MD5_CTX));
        free(buf);

        if(ferror(f) != 0) {
                fclose(f);
                return 2;
        }

        fclose(f);
        return 0;
}

/* third param is so we match the PolarSSL definition */
static int sha2_file(const char *path, unsigned char output[32], int is224)
{
        FILE *f;
        size_t n;
        SHA256_CTX ctx;
        unsigned char *buf;

        CALLOC(buf, 8192, sizeof(unsigned char), return 1);

        if((f = fopen(path, "rb")) == NULL) {
                free(buf);
                return 1;
        }

        if(is224) {
                SHA224_Init(&ctx);
        } else {
                SHA256_Init(&ctx);
        }

        while((n = fread(buf, 1, sizeof(buf), f)) > 0) {
                if(is224) {
                        SHA224_Update(&ctx, buf, n);
                } else {
                        SHA256_Update(&ctx, buf, n);
                }
        }

        if(is224) {
                SHA224_Final(output, &ctx);
        } else {
                SHA256_Final(output, &ctx);
        }

        memset(&ctx, 0, sizeof(SHA256_CTX));
        free(buf);

        if(ferror(f) != 0) {
                fclose(f);
                return 2;
        }

        fclose(f);
        return 0;
}
#endif

/** Get the md5 sum of file.
 * @param filename name of the file
 * @return the checksum on success, NULL on error
 * @addtogroup alpm_misc
 */
char SYMEXPORT *alpm_compute_md5sum(const char *filename)
{
        unsigned char output[16];
        char *md5sum;
        int ret, i;

        ASSERT(filename != NULL, return NULL);

        /* allocate 32 chars plus 1 for null */
        CALLOC(md5sum, 33, sizeof(char), return NULL);
        /* defined above for OpenSSL, otherwise defined in md5.h */
        ret = md5_file(filename, output);

        if(ret > 0) {
                return NULL;
        }

        /* Convert the result to something readable */
        for (i = 0; i < 16; i++) {
                /* sprintf is acceptable here because we know our output */
                sprintf(md5sum +(i * 2), "%02x", output[i]);
        }

        return md5sum;
}

/** Get the sha256 sum of file.
 * @param filename name of the file
 * @return the checksum on success, NULL on error
 * @addtogroup alpm_misc
 */
char SYMEXPORT *alpm_compute_sha256sum(const char *filename)
{
        unsigned char output[32];
        char *sha256sum;
        int ret, i;

        ASSERT(filename != NULL, return NULL);

        /* allocate 64 chars plus 1 for null */
        CALLOC(sha256sum, 65, sizeof(char), return NULL);
        /* defined above for OpenSSL, otherwise defined in sha2.h */
        ret = sha2_file(filename, output, 0);

        if(ret > 0) {
                return NULL;
        }

        /* Convert the result to something readable */
        for (i = 0; i < 32; i++) {
                /* sprintf is acceptable here because we know our output */
                sprintf(sha256sum +(i * 2), "%02x", output[i]);
        }

        return sha256sum;
}

int _alpm_test_checksum(const char *filepath, const char *expected,
                enum _alpm_csum type)
{
        char *computed;
        int ret;

        if(type == ALPM_CSUM_MD5) {
                computed = alpm_compute_md5sum(filepath);
        } else if(type == ALPM_CSUM_SHA256) {
                computed = alpm_compute_sha256sum(filepath);
        } else {
                return -1;
        }

        if(expected == NULL || computed == NULL) {
                ret = -1;
        } else if(strcmp(expected, computed) != 0) {
                ret = 1;
        } else {
                ret = 0;
        }

        FREE(computed);
        return ret;
}

/* Note: does NOT handle sparse files on purpose for speed. */
int _alpm_archive_fgets(struct archive *a, struct archive_read_buffer *b)
{
        char *i = NULL;
        int64_t offset;
        int done = 0;

        /* ensure we start populating our line buffer at the beginning */
        b->line_offset = b->line;

        while(1) {
                /* have we processed this entire block? */
                if(b->block + b->block_size == b->block_offset) {
                        if(b->ret == ARCHIVE_EOF) {
                                /* reached end of archive on the last read, now we are out of data */
                                goto cleanup;
                        }

                        /* zero-copy - this is the entire next block of data. */
                        b->ret = archive_read_data_block(a, (void *)&b->block,
                                        &b->block_size, &offset);
                        b->block_offset = b->block;

                        /* error, cleanup */
                        if(b->ret < ARCHIVE_OK) {
                                goto cleanup;
                        }
                }

                /* loop through the block looking for EOL characters */
                for(i = b->block_offset; i < (b->block + b->block_size); i++) {
                        /* check if read value was null or newline */
                        if(*i == '\0' || *i == '\n') {
                                done = 1;
                                break;
                        }
                }

                /* allocate our buffer, or ensure our existing one is big enough */
                if(!b->line) {
                        /* set the initial buffer to the read block_size */
                        CALLOC(b->line, b->block_size + 1, sizeof(char), b->ret = -ENOMEM; goto cleanup);
                        b->line_size = b->block_size + 1;
                        b->line_offset = b->line;
                } else {
                        size_t needed = (size_t)((b->line_offset - b->line)
                                        + (i - b->block_offset) + 1);
                        if(needed > b->max_line_size) {
                                b->ret = -ERANGE;
                                goto cleanup;
                        }
                        if(needed > b->line_size) {
                                /* need to realloc + copy data to fit total length */
                                char *new;
                                CALLOC(new, needed, sizeof(char), b->ret = -ENOMEM; goto cleanup);
                                memcpy(new, b->line, b->line_size);
                                b->line_size = needed;
                                b->line_offset = new + (b->line_offset - b->line);
                                free(b->line);
                                b->line = new;
                        }
                }

                if(done) {
                        size_t len = (size_t)(i - b->block_offset);
                        memcpy(b->line_offset, b->block_offset, len);
                        b->line_offset[len] = '\0';
                        b->block_offset = ++i;
                        /* this is the main return point; from here you can read b->line */
                        return ARCHIVE_OK;
                } else {
                        /* we've looked through the whole block but no newline, copy it */
                        size_t len = (size_t)(b->block + b->block_size - b->block_offset);
                        memcpy(b->line_offset, b->block_offset, len);
                        b->line_offset += len;
                        b->block_offset = i;
                        /* there was no new data, return what is left; saved ARCHIVE_EOF will be
                         * returned on next call */
                        if(len == 0) {
                                b->line_offset[0] = '\0';
                                return ARCHIVE_OK;
                        }
                }
        }

cleanup:
        {
                int ret = b->ret;
                FREE(b->line);
                memset(b, 0, sizeof(b));
                return ret;
        }
}

int _alpm_splitname(const char *target, char **name, char **version,
                unsigned long *name_hash)
{
        /* the format of a db entry is as follows:
         *    package-version-rel/
         *    package-version-rel/desc (we ignore the filename portion)
         * package name can contain hyphens, so parse from the back- go back
         * two hyphens and we have split the version from the name.
         */
        const char *pkgver, *end;

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

        /* remove anything trailing a '/' */
        end = strchr(target, '/');
        if(!end) {
                end = target + strlen(target);
        }

        /* do the magic parsing- find the beginning of the version string
         * by doing two iterations of same loop to lop off two hyphens */
        for(pkgver = end - 1; *pkgver && *pkgver != '-'; pkgver--);
        for(pkgver = pkgver - 1; *pkgver && *pkgver != '-'; pkgver--);
        if(*pkgver != '-' || pkgver == target) {
                return -1;
        }

        /* copy into fields and return */
        if(version) {
                if(*version) {
                        FREE(*version);
                }
                /* version actually points to the dash, so need to increment 1 and account
                 * for potential end character */
                STRNDUP(*version, pkgver + 1, end - pkgver - 1, return -1);
        }

        if(name) {
                if(*name) {
                        FREE(*name);
                }
                STRNDUP(*name, target, pkgver - target, return -1);
                if(name_hash) {
                        *name_hash = _alpm_hash_sdbm(*name);
                }
        }

        return 0;
}

/**
 * Hash the given string to an unsigned long value.
 * This is the standard sdbm hashing algorithm.
 * @param str string to hash
 * @return the hash value of the given string
 */
unsigned long _alpm_hash_sdbm(const char *str)
{
        unsigned long hash = 0;
        int c;

        if(!str) {
                return hash;
        }
        while((c = *str++)) {
                hash = c + (hash << 6) + (hash << 16) - hash;
        }

        return hash;
}

long _alpm_parsedate(const char *line)
{
        if(isalpha((unsigned char)line[0])) {
                /* initialize to null in case of failure */
                struct tm tmp_tm = { 0 };
                setlocale(LC_TIME, "C");
                strptime(line, "%a %b %e %H:%M:%S %Y", &tmp_tm);
                setlocale(LC_TIME, "");
                return mktime(&tmp_tm);
        }
        return atol(line);
}

/**
 * Wrapper around access() which takes a dir and file argument
 * separately and generates an appropriate error message.
 * If dir is NULL file will be treated as the whole path.
 * @param handle an alpm handle
 * @param dir directory path ending with and slash
 * @param file filename
 * @param amode access mode as described in access()
 * @return int value returned by access()
 */

int _alpm_access(alpm_handle_t *handle, const char *dir, const char *file, int amode)
{
        size_t len = 0;
        int ret = 0;

        if (dir) {
                char *check_path;

                len = strlen(dir) + strlen(file) + 1;
                CALLOC(check_path, len, sizeof(char), RET_ERR(handle, ALPM_ERR_MEMORY, -1));
                snprintf(check_path, len, "%s%s", dir, file);

                ret = access(check_path, amode);
                free(check_path);
        } else {
                dir = "";
                ret = access(file, amode);
        }

        if(ret != 0) {
                if (amode & R_OK) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "\"%s%s\" is not readable: %s\n",
                                        dir, file, strerror(errno));
                }
                if (amode & W_OK) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "\"%s%s\" is not writable: %s\n",
                                        dir, file, strerror(errno));
                }
                if (amode & X_OK) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "\"%s%s\" is not executable: %s\n",
                                        dir, file, strerror(errno));
                }
                if (amode == F_OK) {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "\"%s%s\" does not exist: %s\n",
                                        dir, file, strerror(errno));
                }
        }
        return ret;
}

#ifndef HAVE_STRNDUP
/* A quick and dirty implementation derived from glibc */
static size_t strnlen(const char *s, size_t max)
{
    register const char *p;
    for(p = s; *p && max--; ++p);
    return (p - s);
}

char *strndup(const char *s, size_t n)
{
  size_t len = strnlen(s, n);
  char *new = (char *) malloc(len + 1);

  if(new == NULL)
    return NULL;

  new[len] = '\0';
  return (char *)memcpy(new, s, len);
}
#endif

/* vim: set ts=2 sw=2 noet: */