path: root/lib/libalpm/dload.c

/*
 *  download.c
 *
 *  Copyright (c) 2006-2010 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.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 <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <limits.h>
/* the following two are needed on BSD for libfetch */
#if defined(HAVE_SYS_SYSLIMITS_H)
#include <sys/syslimits.h> /* PATH_MAX */
#endif
#if defined(HAVE_SYS_PARAM_H)
#include <sys/param.h> /* MAXHOSTNAMELEN */
#endif

#if defined(INTERNAL_DOWNLOAD)
#include <fetch.h>
#endif

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

static char *get_filename(const char *url) {
  char *filename = strrchr(url, '/');
  if(filename != NULL) {
    filename++;
  }
  return(filename);
}

#if defined(INTERNAL_DOWNLOAD)
static char *get_destfile(const char *path, const char *filename) {
  char *destfile;
  /* len = localpath len + filename len + null */
  size_t len = strlen(path) + strlen(filename) + 1;
  CALLOC(destfile, len, sizeof(char), RET_ERR(PM_ERR_MEMORY, NULL));
  snprintf(destfile, len, "%s%s", path, filename);

  return(destfile);
}

static char *get_tempfile(const char *path, const char *filename) {
  char *tempfile;
  /* len = localpath len + filename len + '.part' len + null */
  size_t len = strlen(path) + strlen(filename) + 6;
  CALLOC(tempfile, len, sizeof(char), RET_ERR(PM_ERR_MEMORY, NULL));
  snprintf(tempfile, len, "%s%s.part", path, filename);

  return(tempfile);
}

static const char *gethost(struct url *fileurl)
{
  const char *host = _("disk");
  if(strcmp(SCHEME_FILE, fileurl->scheme) != 0) {
    host = fileurl->host;
  }
  return(host);
}

int dload_interrupted;
static RETSIGTYPE inthandler(int signum)
{
  dload_interrupted = 1;
}

#define check_stop() if(dload_interrupted) { ret = -1; goto cleanup; }
enum sighandlers { OLD = 0, NEW = 1 };

static int download_internal(const char *url, const char *localpath,
    int force) {
  FILE *localf = NULL;
  struct stat st;
  int ret = 0;
  off_t dl_thisfile = 0;
  ssize_t nread = 0;
  char *tempfile, *destfile, *filename;
  struct sigaction sig_pipe[2], sig_int[2];

  off_t local_size = 0;
  time_t local_time = 0;

  struct url *fileurl;
  struct url_stat ust;
  fetchIO *dlf = NULL;

  char buffer[PM_DLBUF_LEN];

  filename = get_filename(url);
  if(!filename) {
    _alpm_log(PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
    RET_ERR(PM_ERR_SERVER_BAD_URL, -1);
  }

  fileurl = fetchParseURL(url);
  if(!fileurl) {
    _alpm_log(PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
    RET_ERR(PM_ERR_LIBFETCH, -1);
  }

  destfile = get_destfile(localpath, filename);
  tempfile = get_tempfile(localpath, filename);

  if(stat(tempfile, &st) == 0 && st.st_size > 0) {
    _alpm_log(PM_LOG_DEBUG, "tempfile found, attempting continuation\n");
    local_time = fileurl->last_modified = st.st_mtime;
    local_size = fileurl->offset = (off_t)st.st_size;
    dl_thisfile = st.st_size;
    localf = fopen(tempfile, "ab");
  } else if(!force && stat(destfile, &st) == 0 && st.st_size > 0) {
    _alpm_log(PM_LOG_DEBUG, "destfile found, using mtime only\n");
    local_time = fileurl->last_modified = st.st_mtime;
    local_size = /* no fu->off here */ (off_t)st.st_size;
  } else {
    _alpm_log(PM_LOG_DEBUG, "no file found matching criteria, starting from scratch\n");
  }

  /* pass the raw filename for passing to the callback function */
  _alpm_log(PM_LOG_DEBUG, "using '%s' for download progress\n", filename);

  /* print proxy info for debug purposes */
  _alpm_log(PM_LOG_DEBUG, "HTTP_PROXY: %s\n", getenv("HTTP_PROXY"));
  _alpm_log(PM_LOG_DEBUG, "http_proxy: %s\n", getenv("http_proxy"));
  _alpm_log(PM_LOG_DEBUG, "FTP_PROXY:  %s\n", getenv("FTP_PROXY"));
  _alpm_log(PM_LOG_DEBUG, "ftp_proxy:  %s\n", getenv("ftp_proxy"));

  /* 10s timeout */
  fetchTimeout = 10;

  /* ignore any SIGPIPE signals- these may occur if our FTP socket dies or
   * something along those lines. Store the old signal handler first. */
  sig_pipe[NEW].sa_handler = SIG_IGN;
  sigemptyset(&sig_pipe[NEW].sa_mask);
  sig_pipe[NEW].sa_flags = 0;
  sigaction(SIGPIPE, NULL, &sig_pipe[OLD]);
  sigaction(SIGPIPE, &sig_pipe[NEW], NULL);

  dload_interrupted = 0;
  sig_int[NEW].sa_handler = &inthandler;
  sigemptyset(&sig_int[NEW].sa_mask);
  sig_int[NEW].sa_flags = 0;
  sigaction(SIGINT, NULL, &sig_int[OLD]);
  sigaction(SIGINT, &sig_int[NEW], NULL);

  /* NOTE: libfetch does not reset the error code, be sure to do it before
   * calls into the library */

  /* find out the remote size *and* mtime in one go. there is a lot of
   * trouble in trying to do both size and "if-modified-since" logic in a
   * non-stat request, so avoid it. */
  fetchLastErrCode = 0;
  if(fetchStat(fileurl, &ust, "") == -1) {
    pm_errno = PM_ERR_LIBFETCH;
    _alpm_log(PM_LOG_ERROR, _("failed retrieving file '%s' from %s : %s\n"),
        filename, gethost(fileurl), fetchLastErrString);
    ret = -1;
    goto cleanup;
  }
  check_stop();

  _alpm_log(PM_LOG_DEBUG, "ust.mtime: %ld local_time: %ld compare: %ld\n",
      ust.mtime, local_time, local_time - ust.mtime);
  _alpm_log(PM_LOG_DEBUG, "ust.size: %"PRId64" local_size: %"PRId64" compare: %"PRId64"\n",
      ust.size, local_size, local_size - ust.size);
  if(!force && ust.mtime && ust.mtime == local_time
      && ust.size && ust.size == local_size) {
    /* the remote time and size values agreed with what we have, so move on
     * because there is nothing more to do. */
    _alpm_log(PM_LOG_DEBUG, "files are identical, skipping %s\n", filename);
    ret = 1;
    goto cleanup;
  }
  if(!ust.mtime || ust.mtime != local_time) {
    _alpm_log(PM_LOG_DEBUG, "mtimes were different or unavailable, downloading %s from beginning\n", filename);
    fileurl->offset = 0;
  }

  fetchLastErrCode = 0;
  dlf = fetchGet(fileurl, "");
  check_stop();

  if(fetchLastErrCode != 0 || dlf == NULL) {
    pm_errno = PM_ERR_LIBFETCH;
    _alpm_log(PM_LOG_ERROR, _("failed retrieving file '%s' from %s : %s\n"),
        filename, gethost(fileurl), fetchLastErrString);
    ret = -1;
    goto cleanup;
  } else {
    _alpm_log(PM_LOG_DEBUG, "connected to %s successfully\n", fileurl->host);
  }

  if(localf && fileurl->offset == 0) {
    _alpm_log(PM_LOG_WARNING, _("resuming download of %s not possible; starting over\n"), filename);
    fclose(localf);
    localf = NULL;
  } else if(fileurl->offset) {
    _alpm_log(PM_LOG_DEBUG, "resuming download at position %"PRId64"\n", fileurl->offset);
  }


  if(localf == NULL) {
    _alpm_rmrf(tempfile);
    fileurl->offset = (off_t)0;
    dl_thisfile = 0;
    localf = fopen(tempfile, "wb");
    if(localf == NULL) { /* still null? */
      pm_errno = PM_ERR_RETRIEVE;
      _alpm_log(PM_LOG_ERROR, _("error writing to file '%s': %s\n"),
          tempfile, strerror(errno));
      ret = -1;
      goto cleanup;
    }
  }

  /* Progress 0 - initialize */
  if(handle->dlcb) {
    handle->dlcb(filename, 0, ust.size);
  }

  while((nread = fetchIO_read(dlf, buffer, PM_DLBUF_LEN)) > 0) {
    check_stop();
    size_t nwritten = 0;
    nwritten = fwrite(buffer, 1, nread, localf);
    if((nwritten != nread) || ferror(localf)) {
      pm_errno = PM_ERR_RETRIEVE;
      _alpm_log(PM_LOG_ERROR, _("error writing to file '%s': %s\n"),
          tempfile, strerror(errno));
      ret = -1;
      goto cleanup;
    }
    dl_thisfile += nread;

    if(handle->dlcb) {
      handle->dlcb(filename, dl_thisfile, ust.size);
    }
  }

  /* did the transfer complete normally? */
  if (nread == -1) {
    /* not PM_ERR_LIBFETCH here because libfetch error string might be empty */
    pm_errno = PM_ERR_RETRIEVE;
    _alpm_log(PM_LOG_ERROR, _("failed retrieving file '%s' from %s\n"),
        filename, gethost(fileurl));
    ret = -1;
    goto cleanup;
  }

  if (ust.size != -1 && dl_thisfile < ust.size) {
    pm_errno = PM_ERR_RETRIEVE;
    _alpm_log(PM_LOG_ERROR, _("%s appears to be truncated: %jd/%jd bytes\n"),
        filename, (intmax_t)dl_thisfile, (intmax_t)ust.size);
    ret = -1;
    goto cleanup;
  }

  /* probably safer to close the file descriptors now before renaming the file,
   * for example to make sure the buffers are flushed.
   */
  fclose(localf);
  localf = NULL;
  fetchIO_close(dlf);
  dlf = NULL;

  /* set the times on the file to the same as that of the remote file */
  if(ust.mtime) {
    struct timeval tv[2];
    memset(&tv, 0, sizeof(tv));
    tv[0].tv_sec = ust.atime;
    tv[1].tv_sec = ust.mtime;
    utimes(tempfile, tv);
  }
  rename(tempfile, destfile);
  ret = 0;

cleanup:
  FREE(tempfile);
  FREE(destfile);
  if(localf != NULL) {
    /* if we still had a local file open, we got interrupted. set the mtimes on
     * the file accordingly. */
    fflush(localf);
    if(ust.mtime) {
      struct timeval tv[2];
      memset(&tv, 0, sizeof(tv));
      tv[0].tv_sec = ust.atime;
      tv[1].tv_sec = ust.mtime;
      futimes(fileno(localf), tv);
    }
    fclose(localf);
  }
  if(dlf != NULL) {
    fetchIO_close(dlf);
  }
  fetchFreeURL(fileurl);

  /* restore the old signal handlers */
  sigaction(SIGINT, &sig_int[OLD], NULL);
  sigaction(SIGPIPE, &sig_pipe[OLD], NULL);
  /* if we were interrupted, trip the old handler */
  if(dload_interrupted) {
    raise(SIGINT);
  }

  return(ret);
}
#endif

static int download(const char *url, const char *localpath,
    int force) {
  if(handle->fetchcb == NULL) {
#if defined(INTERNAL_DOWNLOAD)
    return(download_internal(url, localpath, force));
#else
    RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
#endif
  } else {
    int ret = handle->fetchcb(url, localpath, force);
    if(ret == -1) {
      RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
    }
    return(ret);
  }
}

/*
 * Download a single file
 *   - servers must be a list of urls WITHOUT trailing slashes.
 *
 * RETURN:  0 for successful download
 *          1 if the files are identical
 *         -1 on error
 */
int _alpm_download_single_file(const char *filename,
    alpm_list_t *servers, const char *localpath,
    int force)
{
  alpm_list_t *i;
  int ret = -1;

  ASSERT(servers != NULL, RET_ERR(PM_ERR_SERVER_NONE, -1));

  for(i = servers; i; i = i->next) {
    const char *server = i->data;
    char *fileurl = NULL;
    size_t len;

    /* print server + filename into a buffer */
    len = strlen(server) + strlen(filename) + 2;
    CALLOC(fileurl, len, sizeof(char), RET_ERR(PM_ERR_MEMORY, -1));
    snprintf(fileurl, len, "%s/%s", server, filename);

    ret = download(fileurl, localpath, force);
    FREE(fileurl);
    if(ret != -1) {
      break;
    }
  }

  return(ret);
}

int _alpm_download_files(alpm_list_t *files,
    alpm_list_t *servers, const char *localpath)
{
  int ret = 0;
  alpm_list_t *lp;

  for(lp = files; lp; lp = lp->next) {
    char *filename = lp->data;
    if(_alpm_download_single_file(filename, servers,
          localpath, 0) == -1) {
      ret++;
    }
  }

  return(ret);
}

/** Fetch a remote pkg.
 * @param url URL of the package to download
 * @return the downloaded filepath on success, NULL on error
 * @addtogroup alpm_misc
 */
char SYMEXPORT *alpm_fetch_pkgurl(const char *url)
{
  char *filename, *filepath;
  const char *cachedir;
  int ret;

  ALPM_LOG_FUNC;

  filename = get_filename(url);

  /* find a valid cache dir to download to */
  cachedir = _alpm_filecache_setup();

  /* download the file */
  ret = download(url, cachedir, 0);
  if(ret == -1) {
    _alpm_log(PM_LOG_WARNING, _("failed to download %s\n"), url);
    return(NULL);
  }
  _alpm_log(PM_LOG_DEBUG, "successfully downloaded %s\n", url);

  /* we should be able to find the file the second time around */
  filepath = _alpm_filecache_find(filename);
  return(filepath);
}

/* vim: set ts=2 sw=2 noet: */