path: root/lib/libalpm/util.c

/*
 *  util.c
 *
 *  Copyright (c) 2002-2007 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 <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <time.h>
#include <syslog.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

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

/* libalpm */
#include "util.h"
#include "log.h"
#include "package.h"
#include "alpm.h"
#include "alpm_list.h"
#include "md5.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))) {
    fwrite(buf, 1, len, out);
  }

  /* 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((int)*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((int)*pch)) {
    pch--;
  }
  *++pch = '\0';

  return(str);
}

/* Helper function for _alpm_strreplace */
static void _strnadd(char **str, const char *append, unsigned int count)
{
  if(*str) {
    *str = realloc(*str, strlen(*str) + count + 1);
  } else {
    *str = calloc(count + 1, sizeof(char));
  }

  strncat(*str, append, count);
}

/* Replace all occurances of 'needle' with 'replace' in 'str', returning
 * a new string (must be free'd) */
char *_alpm_strreplace(const char *str, const char *needle, const char *replace)
{
  const char *p, *q;
  p = q = str;

  char *newstr = NULL;
  unsigned int needlesz = strlen(needle),
               replacesz = strlen(replace);

  while (1) {
    q = strstr(p, needle);
    if(!q) { /* not found */
      if(*p) {
        /* add the rest of 'p' */
        _strnadd(&newstr, p, strlen(p));
      }
      break;
    } else { /* found match */
      if(q > p){
        /* add chars between this occurance and last occurance, if any */
        _strnadd(&newstr, p, q - p);
      }
      _strnadd(&newstr, replace, replacesz);
      p = q + needlesz;
    }
  }

  return newstr;
}


/* Create a lock file */
int _alpm_lckmk()
{
  int fd;
  pid_t pid;
  char *dir, *ptr, *spid = NULL;
  const char *file = alpm_option_get_lockfile();

  /* create the dir of the lockfile first */
  dir = strdup(file);
  ptr = strrchr(dir, '/');
  if(ptr) {
    *ptr = '\0';
  }
  _alpm_makepath(dir);
  FREE(dir);

  while((fd = open(file, O_WRONLY | O_CREAT | O_EXCL, 0000)) == -1
      && errno == EINTR);
  if(fd > 0) {
    pid = getpid();
    size_t len = snprintf(spid, 0, "%ld\n", (long)pid) + 1;
    spid = malloc(len);
    snprintf(spid, len, "%ld\n", (long)pid);
    while(write(fd, (void *)spid, len) == -1 && errno == EINTR);
    fsync(fd);
    free(spid);
    return(fd);
  }
  return(-1);
}

/* Remove a lock file */
int _alpm_lckrm()
{
  const char *file = alpm_option_get_lockfile();
  if(unlink(file) == -1 && errno != ENOENT) {
    return(-1);
  }
  return(0);
}

/* Compression functions */

/**
 * @brief Unpack a specific file or all files in an archive.
 *
 * @param archive  the archive to unpack
 * @param prefix   where to extract the files
 * @param fn       a file within the archive to unpack or NULL for all
 */
int _alpm_unpack(const char *archive, const char *prefix, const char *fn)
{
  int ret = 1;
  mode_t oldmask;
  struct archive *_archive;
  struct archive_entry *entry;
  char expath[PATH_MAX];

  ALPM_LOG_FUNC;

  if((_archive = archive_read_new()) == NULL)
    RET_ERR(PM_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(PM_LOG_ERROR, _("could not open %s: %s\n"), archive,
        archive_error_string(_archive));
    RET_ERR(PM_ERR_PKG_OPEN, -1);
  }

  oldmask = umask(0022);
  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_mode(entry, 0644);
    } else if(S_ISDIR(st->st_mode)) {
      archive_entry_set_mode(entry, 0755);
    }

    /* If a specific file was requested skip entries that don't match. */
    if (fn && strcmp(fn, entryname)) {
      _alpm_log(PM_LOG_DEBUG, "skipping: %s\n", entryname);
      if (archive_read_data_skip(_archive) != ARCHIVE_OK) {
        ret = 1;
        goto cleanup;
      }
      continue;
    }

    /* Extract the archive entry. */
    ret = 0;
    snprintf(expath, PATH_MAX, "%s/%s", prefix, entryname);
    archive_entry_set_pathname(entry, expath);

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

    if(fn) {
      break;
    }
  }

cleanup:
  umask(oldmask);
  archive_read_finish(_archive);
  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 {
      if((dirp = opendir(path)) == (DIR *)-1) {
        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, "..") && strcmp(dp->d_name, ".")) {
            errflag += _alpm_rmrf(name);
          }
        }
      }
      closedir(dirp);
      if(rmdir(path)) {
        errflag++;
      }
    }
    return(errflag);
  }
  return(0);
}

int _alpm_logaction(unsigned short usesyslog, FILE *f,
    const char *fmt, va_list args)
{
  int ret = 0;

  if(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(f) {
    time_t t;
    struct tm *tm;

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

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

  return(ret);
}

int _alpm_ldconfig(const char *root)
{
  char line[PATH_MAX];

  snprintf(line, PATH_MAX, "%setc/ld.so.conf", root);
  if(access(line, F_OK) == 0) {
    snprintf(line, PATH_MAX, "%ssbin/ldconfig", root);
    if(access(line, X_OK) == 0) {
      char cmd[PATH_MAX];
      snprintf(cmd, PATH_MAX, "%s -r %s", line, root);
      system(cmd);
    }
  }

  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 filename name of file to find
 * @return malloced path of file, NULL if not found
 */
char *_alpm_filecache_find(const char* filename)
{
  char path[PATH_MAX];
  char *retpath;
  alpm_list_t *i;

  /* Loop through the cache dirs until we find a matching file */
  for(i = alpm_option_get_cachedirs(); i; i = alpm_list_next(i)) {
    snprintf(path, PATH_MAX, "%s%s", (char*)alpm_list_getdata(i),
        filename);
    if(access(path, R_OK) == 0) {
      retpath = strdup(path);
      _alpm_log(PM_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.
 * @return pointer to a writable cache directory.
 */
const char *_alpm_filecache_setup(void)
{
  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(); i; i = alpm_list_next(i)) {
    cachedir = alpm_list_getdata(i);
    if(stat(cachedir, &buf) != 0) {
      /* cache directory does not exist.... try creating it */
      _alpm_log(PM_LOG_WARNING, _("no %s cache exists, creating...\n"),
          cachedir);
      if(_alpm_makepath(cachedir) == 0) {
        _alpm_log(PM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
        return(cachedir);
      }
    } else if(S_ISDIR(buf.st_mode) && (buf.st_mode & S_IWUSR)) {
      _alpm_log(PM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
      return(cachedir);
    }
  }

  /* we didn't find a valid cache directory. use /tmp. */
  tmp = alpm_list_add(NULL, strdup("/tmp/"));
  alpm_option_set_cachedirs(tmp);
  _alpm_log(PM_LOG_DEBUG, "using cachedir: %s", "/tmp/\n");
  _alpm_log(PM_LOG_WARNING, _("couldn't create package cache, using /tmp instead\n"));
  return(alpm_list_getdata(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;
  char *newpath = strdup(path);
  int len = strlen(newpath);

  /* strip the trailing slash if one exists */
  if(len != 0 && newpath[len - 1] == '/') {
      newpath[len - 1] = '\0';
  }

  ret = lstat(newpath, buf);

  FREE(newpath);
  return(ret);
}

/** 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;

  ALPM_LOG_FUNC;

  ASSERT(filename != NULL, return(NULL));

  /* allocate 32 chars plus 1 for null */
  md5sum = calloc(33, sizeof(char));
  ret = md5_file(filename, output);

  if (ret > 0) {
    RET_ERR(PM_ERR_NOT_A_FILE, 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]);
  }
  md5sum[32] = '\0';

  _alpm_log(PM_LOG_DEBUG, "md5(%s) = %s\n", filename, md5sum);
  return(md5sum);
}

int _alpm_test_md5sum(const char *filepath, const char *md5sum)
{
  char *md5sum2;
  int ret;

  md5sum2 = alpm_compute_md5sum(filepath);

  if(md5sum == NULL || md5sum2 == NULL) {
    ret = -1;
  } else if(strcmp(md5sum, md5sum2) != 0) {
    ret = 1;
  } else {
    ret = 0;
  }

  FREE(md5sum2);
  return(ret);
}

char *_alpm_archive_fgets(char *line, size_t size, struct archive *a)
{
  /* for now, just read one char at a time until we get to a
   * '\n' char. we can optimize this later with an internal
   * buffer. */
  /* leave room for zero terminator */
  char *last = line + size - 1;
  char *i;

  for(i = line; i < last; i++) {
    int ret = archive_read_data(a, i, 1);
    /* special check for first read- if null, return null,
     * this indicates EOF */
    if(i == line && (ret <= 0 || *i == '\0')) {
      return(NULL);
    }
    /* check if read value was null or newline */
    if(ret <= 0 || *i == '\0' || *i == '\n') {
      last = i + 1;
      break;
    }
  }

  /* always null terminate the buffer */
  *last = '\0';

  return(line);
}

/* vim: set ts=2 sw=2 noet: */