Move important information up in -Si output

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

/*
 *  util.c
 *
 *  Copyright (c) 2006-2012 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 <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <time.h>
#include <syslog.h>
#include <errno.h>
#include <limits.h>
#include <sys/wait.h>
#include <locale.h> /* setlocale */
#include <fnmatch.h>

/* 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
/** Extracts tokens from a string.
 * Replaces strset which is not portable (missing on Solaris).
 * Copyright (c) 2001 by François Gouget <fgouget_at_codeweavers.com>
 * Modifies str to point to the first character after the token if one is
 * found, or NULL if one is not.
 * @param str string containing delimited tokens to parse
 * @param delim character delimiting tokens in str
 * @return pointer to the first token in str if str is not NULL, NULL if
 * str is NULL
 */
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);
}

/** Creates a directory, including parents if needed, similar to 'mkdir -p'.
 * @param path directory path to create
 * @param mode permission mode for created directories
 * @return 0 on success, 1 on error
 */
int _alpm_makepath_mode(const char *path, mode_t mode)
{
        char *ptr, *str;
        mode_t oldmask;
        int ret = 0;

        STRDUP(str, path, return 1);

        oldmask = umask(0000);

        for(ptr = str; *ptr; ptr++) {
                /* detect mid-path condition and zero length paths */
                if(*ptr != '/' || ptr == str || ptr[-1] == '/') {
                        continue;
                }

                /* temporarily mask the end of the path */
                *ptr = '\0';

                if(mkdir(str, mode) < 0 && errno != EEXIST) {
                        ret = 1;
                        goto done;
                }

                /* restore path separator */
                *ptr = '/';
        }

        /* end of the string. add the full path. It will already exist when the path
         * passed in has a trailing slash. */
        if(mkdir(str, mode) < 0 && errno != EEXIST) {
                ret = 1;
        }

done:
        umask(oldmask);
        free(str);
        return ret;
}

/** Copies a file.
 * @param src file path to copy from
 * @param dest file path to copy to
 * @return 0 on success, 1 on error 
 */
int _alpm_copyfile(const char *src, const char *dest)
{
        char *buf;
        int in, out, ret = 1;
        ssize_t nread;
        struct stat st;

        MALLOC(buf, (size_t)ALPM_BUFFER_SIZE, return 1);

        OPEN(in, src, O_RDONLY);
        do {
                out = open(dest, O_WRONLY | O_CREAT, 0000);
        } while(out == -1 && errno == EINTR);
        if(in < 0 || out < 0) {
                goto cleanup;
        }

        if(fstat(in, &st) || fchmod(out, st.st_mode)) {
                goto cleanup;
        }

        /* do the actual file copy */
        while((nread = read(in, buf, ALPM_BUFFER_SIZE)) > 0 || errno == EINTR) {
                ssize_t nwrite = 0;
                if(nread < 0) {
                        continue;
                }
                do {
                        nwrite = write(out, buf + nwrite, nread);
                        if(nwrite >= 0) {
                                nread -= nwrite;
                        } else if(errno != EINTR) {
                                goto cleanup;
                        }
                } while(nread > 0);
        }
        ret = 0;

cleanup:
        free(buf);
        if(in >= 0) {
                CLOSE(in);
        }
        if(out >= 0) {
                CLOSE(out);
        }
        return ret;
}

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

        return len;
}

/* Compression functions */

/** Open an archive for reading and perform the necessary boilerplate.
 * This takes care of creating the libarchive 'archive' struct, setting up
 * compression and format options, opening a file descriptor, setting up the
 * buffer size, and performing a stat on the path once opened.
 * On error, no file descriptor is opened, and the archive pointer returned
 * will be set to NULL.
 * @param handle the context handle
 * @param path the path of the archive to open
 * @param buf space for a stat buffer for the given path
 * @param archive pointer to place the created archive object
 * @param error error code to set on failure to open archive
 * @return -1 on failure, >=0 file descriptor on success
 */
int _alpm_open_archive(alpm_handle_t *handle, const char *path,
                struct stat *buf, struct archive **archive, alpm_errno_t error)
{
        int fd;
        size_t bufsize = ALPM_BUFFER_SIZE;
        errno = 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);

        _alpm_log(handle, ALPM_LOG_DEBUG, "opening archive %s\n", path);
        OPEN(fd, path, O_RDONLY);
        if(fd < 0) {
                _alpm_log(handle, ALPM_LOG_ERROR,
                                _("could not open file %s: %s\n"), path, strerror(errno));
                goto error;
        }

        if(fstat(fd, buf) != 0) {
                _alpm_log(handle, ALPM_LOG_ERROR,
                                _("could not stat file %s: %s\n"), path, strerror(errno));
                goto error;
        }
#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
        if(buf->st_blksize > ALPM_BUFFER_SIZE) {
                bufsize = buf->st_blksize;
        }
#endif

        if(archive_read_open_fd(*archive, fd, bufsize) != ARCHIVE_OK) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not open file %s: %s\n"),
                                path, archive_error_string(*archive));
                goto error;
        }

        return fd;

error:
        archive_read_finish(*archive);
        *archive = NULL;
        if(fd >= 0) {
                CLOSE(fd);
        }
        RET_ERR(handle, error, -1);
}

/** 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;
}

/** Unpack a list of files in an archive.
 * @param handle the context handle
 * @param path 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 *path, const char *prefix,
                alpm_list_t *list, int breakfirst)
{
        int ret = 0;
        mode_t oldmask;
        struct archive *archive;
        struct archive_entry *entry;
        struct stat buf;
        int fd, cwdfd;

        fd = _alpm_open_archive(handle, path, &buf, &archive, ALPM_ERR_PKG_OPEN);
        if(fd < 0) {
                return 1;
        }

        oldmask = umask(0022);

        /* save the cwd so we can restore it later */
        OPEN(cwdfd, ".", O_RDONLY);
        if(cwdfd < 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not get current working directory\n"));
        }

        /* 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 char *entryname;
                mode_t mode;

                entryname = archive_entry_pathname(entry);

                /* 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);
                        }
                }

                mode = archive_entry_mode(entry);
                if(S_ISREG(mode)) {
                        archive_entry_set_perm(entry, 0644);
                } else if(S_ISDIR(mode)) {
                        archive_entry_set_perm(entry, 0755);
                }

                /* 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);
        CLOSE(fd);
        if(cwdfd >= 0) {
                if(fchdir(cwdfd) != 0) {
                        _alpm_log(handle, ALPM_LOG_ERROR,
                                        _("could not restore working directory (%s)\n"), strerror(errno));
                }
                CLOSE(cwdfd);
        }

        return ret;
}

/** 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;
}

/** Write formatted message to log.
 * @param handle the context handle
 * @param format formatted string to write out
 * @param args formatting arguments
 * @return 0 or number of characters written on success, vfprintf return value
 * on error
 */
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;
}

/** Execute a command with arguments in a chroot.
 * @param handle the context handle
 * @param cmd command to execute
 * @param argv arguments to pass to cmd
 * @return 0 on success, 1 on error
 */
int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const argv[])
{
        pid_t pid;
        int pipefd[2], cwdfd;
        int retval = 0;

        /* save the cwd so we can restore it later */
        OPEN(cwdfd, ".", O_RDONLY);
        if(cwdfd < 0) {
                _alpm_log(handle, ALPM_LOG_ERROR, _("could not get current working directory\n"));
        }

        /* 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",
                        cmd, 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(cmd, argv);
                /* execv only returns if there was an error */
                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, ALPM_EVENT_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(cwdfd >= 0) {
                if(fchdir(cwdfd) != 0) {
                        _alpm_log(handle, ALPM_LOG_ERROR,
                                        _("could not restore working directory (%s)\n"), strerror(errno));
                }
                CLOSE(cwdfd);
        }

        return retval;
}

/** Run ldconfig in a chroot.
 * @param handle the context handle
 * @return 0 on success, 1 on error
 */
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 arg0[32];
                        char *argv[] = { arg0, NULL };
                        strcpy(arg0, "ldconfig");
                        return _alpm_run_chroot(handle, "/sbin/ldconfig", argv);
                }
        }

        return 0;
}

/** Helper function for comparing strings using the alpm "compare func"
 * signature.
 * @param s1 first string to be compared
 * @param s2 second string to be compared
 * @return 0 if strings are equal, positive int if first unequal character
 * has a greater value in s1, negative if it has a greater value in s2
 */
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 = handle->cachedirs; i; i = i->next) {
                snprintf(path, PATH_MAX, "%s%s", (char *)i->data,
                                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;
        char *cachedir;
        const char *tmpdir;

        /* Loop through the cache dirs until we find a usable directory */
        for(i = handle->cachedirs; i; i = i->next) {
                cachedir = i->data;
                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)) {
                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                        "skipping cachedir, not a directory: %s\n", cachedir);
                } else if(_alpm_access(handle, NULL, cachedir, W_OK) != 0) {
                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                        "skipping cachedir, not writable: %s\n", cachedir);
                } else if(!(buf.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH))) {
                        _alpm_log(handle, ALPM_LOG_DEBUG,
                                        "skipping cachedir, no write bits set: %s\n", cachedir);
                } else {
                        _alpm_log(handle, ALPM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
                        return cachedir;
                }
        }

        /* we didn't find a valid cache directory. use TMPDIR or /tmp. */
        if((tmpdir = getenv("TMPDIR")) && stat(tmpdir, &buf) && S_ISDIR(buf.st_mode)) {
                /* TMPDIR was good, we can use it */
        } else {
                tmpdir = "/tmp";
        }
        alpm_option_add_cachedir(handle, tmpdir);
        cachedir = handle->cachedirs->prev->data;
        _alpm_log(handle, ALPM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
        _alpm_log(handle, ALPM_LOG_WARNING,
                        _("couldn't find or create package cache, using %s instead\n"), cachedir);
        return cachedir;
}

/** 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
/** Compute the MD5 message digest of a file.
 * @param path file path of file to compute  MD5 digest of
 * @param output string to hold computed MD5 digest
 * @return 0 on success, 1 on file open error, 2 on file read error
 */
static int md5_file(const char *path, unsigned char output[16])
{
        MD5_CTX ctx;
        unsigned char *buf;
        ssize_t n;
        int fd;

        MALLOC(buf, (size_t)ALPM_BUFFER_SIZE, return 1);

        OPEN(fd, path, O_RDONLY);
        if(fd < 0) {
                free(buf);
                return 1;
        }

        MD5_Init(&ctx);

        while((n = read(fd, buf, ALPM_BUFFER_SIZE)) > 0 || errno == EINTR) {
                if(n < 0) {
                        continue;
                }
                MD5_Update(&ctx, buf, n);
        }

        CLOSE(fd);
        free(buf);

        if(n < 0) {
                return 2;
        }

        MD5_Final(output, &ctx);
        return 0;
}

/* third param is so we match the PolarSSL definition */
/** Compute the SHA-224 or SHA-256 message digest of a file.
 * @param path file path of file to compute SHA2 digest of
 * @param output string to hold computed SHA2 digest
 * @param is224 use SHA-224 instead of SHA-256
 * @return 0 on success, 1 on file open error, 2 on file read error
 */
static int sha2_file(const char *path, unsigned char output[32], int is224)
{
        SHA256_CTX ctx;
        unsigned char *buf;
        ssize_t n;
        int fd;

        MALLOC(buf, (size_t)ALPM_BUFFER_SIZE, return 1);

        OPEN(fd, path, O_RDONLY);
        if(fd < 0) {
                free(buf);
                return 1;
        }

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

        while((n = read(fd, buf, ALPM_BUFFER_SIZE)) > 0 || errno == EINTR) {
                if(n < 0) {
                        continue;
                }
                if(is224) {
                        SHA224_Update(&ctx, buf, n);
                } else {
                        SHA256_Update(&ctx, buf, n);
                }
        }

        CLOSE(fd);
        free(buf);

        if(n < 0) {
                return 2;
        }

        if(is224) {
                SHA224_Final(output, &ctx);
        } else {
                SHA256_Final(output, &ctx);
        }
        return 0;
}
#endif

/** Create a string representing bytes in hexadecimal.
 * @param bytes the bytes to represent in hexadecimal
 * @param size number of bytes to consider
 * @return a NULL terminated string with the hexadecimal representation of
 * bytes or NULL on error. This string must be freed.
 */
static char *hex_representation(unsigned char *bytes, size_t size)
{
        static const char *hex_digits = "0123456789abcdef";
        char *str;
        size_t i;

        MALLOC(str, 2 * size + 1, return NULL);

        for (i = 0; i < size; i++) {
                str[2 * i] = hex_digits[bytes[i] >> 4];
                str[2 * i + 1] = hex_digits[bytes[i] & 0x0f];
        }

        str[2 * size] = '\0';

        return str;
}

/** 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];

        ASSERT(filename != NULL, return NULL);

        /* defined above for OpenSSL, otherwise defined in md5.h */
        if(md5_file(filename, output) > 0) {
                return NULL;
        }

        return hex_representation(output, 16);
}

/** 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];

        ASSERT(filename != NULL, return NULL);

        /* defined above for OpenSSL, otherwise defined in sha2.h */
        if(sha2_file(filename, output, 0) > 0) {
                return NULL;
        }

        return hex_representation(output, 32);
}

/** Calculates a file's MD5 or SHA2 digest  and compares it to an expected value. 
 * @param filepath path of the file to check
 * @param expected hash value to compare against
 * @param type digest type to use
 * @return 0 if file matches the expected hash, 1 if they do not match, -1 on
 * error
 */
int _alpm_test_checksum(const char *filepath, const char *expected,
                alpm_pkgvalidation_t type)
{
        char *computed;
        int ret;

        if(type == ALPM_PKG_VALIDATION_MD5SUM) {
                computed = alpm_compute_md5sum(filepath);
        } else if(type == ALPM_PKG_VALIDATION_SHA256SUM) {
                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. */
/** TODO.
 * Does not handle sparse files on purpose for speed.
 * @param a
 * @param b
 * @return 
 */
int _alpm_archive_fgets(struct archive *a, struct archive_read_buffer *b)
{
        /* ensure we start populating our line buffer at the beginning */
        b->line_offset = b->line;

        while(1) {
                size_t block_remaining;
                char *eol;

                /* have we processed this entire block? */
                if(b->block + b->block_size == b->block_offset) {
                        int64_t 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;
                        block_remaining = b->block_size;

                        /* error, cleanup */
                        if(b->ret < ARCHIVE_OK) {
                                goto cleanup;
                        }
                } else {
                        block_remaining = b->block + b->block_size - b->block_offset;
                }

                /* look through the block looking for EOL characters */
                eol = memchr(b->block_offset, '\n', block_remaining);
                if(!eol) {
                        eol = memchr(b->block_offset, '\0', block_remaining);
                }

                /* 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 {
                        /* note: we know eol > b->block_offset and b->line_offset > b->line,
                         * so we know the result is unsigned and can fit in size_t */
                        size_t new = eol ? (size_t)(eol - b->block_offset) : block_remaining;
                        size_t needed = (size_t)((b->line_offset - b->line) + new + 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_line;
                                CALLOC(new_line, needed, sizeof(char), b->ret = -ENOMEM; goto cleanup);
                                memcpy(new_line, b->line, b->line_size);
                                b->line_size = needed;
                                b->line_offset = new_line + (b->line_offset - b->line);
                                free(b->line);
                                b->line = new_line;
                        }
                }

                if(eol) {
                        size_t len = (size_t)(eol - b->block_offset);
                        memcpy(b->line_offset, b->block_offset, len);
                        b->line_offset[len] = '\0';
                        b->block_offset = eol + 1;
                        b->real_line_size = b->line_offset + len - b->line;
                        /* 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 = b->block + b->block_size;
                        /* 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';
                                b->real_line_size = b->line_offset - b->line;
                                return ARCHIVE_OK;
                        }
                }
        }

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

/** Parse a full package specifier.
 * @param target package specifier to parse, such as: "pacman-4.0.1-2",
 * "pacman-4.01-2/", or "pacman-4.0.1-2/desc"
 * @param name to hold package name
 * @param version to hold package version
 * @param name_hash to hold package name hash
 * @return 0 on success, -1 on error
 */
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 * 65599;
        }

        return hash;
}

/** Convert a string to a file offset.
 * This parses bare positive integers only.
 * @param line string to convert
 * @return off_t on success, -1 on error
 */
off_t _alpm_strtoofft(const char *line)
{
        char *end;
        unsigned long long result;
        errno = 0;

        /* we are trying to parse bare numbers only, no leading anything */
        if(!isdigit((unsigned char)line[0])) {
                return (off_t)-1;
        }
        result = strtoull(line, &end, 10);
        if(result == 0 && end == line) {
                /* line was not a number */
                return (off_t)-1;
        } else if(result == ULLONG_MAX && errno == ERANGE) {
                /* line does not fit in unsigned long long */
                return (off_t)-1;
        } else if(*end) {
                /* line began with a number but has junk left over at the end */
                return (off_t)-1;
        }

        return (off_t)result;
}

/** Parses a date into an alpm_time_t struct.
 * @param line date to parse
 * @return time struct on success, 0 on error
 */
alpm_time_t _alpm_parsedate(const char *line)
{
        char *end;
        long long result;
        errno = 0;

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

        result = strtoll(line, &end, 10);
        if(result == 0 && end == line) {
                /* line was not a number */
                errno = EINVAL;
                return 0;
        } else if(errno == ERANGE) {
                /* line does not fit in long long */
                return 0;
        } else if(*end) {
                /* line began with a number but has junk left over at the end */
                errno = EINVAL;
                return 0;
        }

        return (alpm_time_t)result;
}

/** 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;
}

/** Checks whether a string matches a shell wildcard pattern.
 * Wrapper around fnmatch.
 * @param pattern pattern to match aganist
 * @param string string to check against pattern
 * @return 0 if string matches pattern, non-zero if they don't match and on
 * error
 */
int _alpm_fnmatch(const void *pattern, const void *string)
{
        return fnmatch(pattern, string, 0);
}

void _alpm_alloc_fail(size_t size)
{
        fprintf(stderr, "alloc failure: could not allocate %zd bytes\n", size);
}

#ifndef HAVE_STRNDUP
/* A quick and dirty implementation derived from glibc */
/** Determines the length of a fixed-size string.
 * @param s string to be measured
 * @param max maximum number of characters to search for the string end
 * @return length of s or max, whichever is smaller
 */
static size_t strnlen(const char *s, size_t max)
{
    register const char *p;
    for(p = s; *p && max--; ++p);
    return (p - s);
}

/** Copies a string.
 * Returned string needs to be freed
 * @param s string to be copied
 * @param n maximum number of characters to copy
 * @return pointer to the new string on success, NULL on error
 */
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: */