path: root/lib/libalpm/dload.c

/*
 *  download.c
 *
 *  Copyright (c) 2006-2011 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>

#ifdef HAVE_LIBCURL
#include <curl/curl.h>
#endif

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

static int prevprogress; /* last download amount */

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

#ifdef HAVE_LIBCURL
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;
}

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

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

static int curl_progress(void *filename, double dltotal, double dlnow,
    double ultotal, double ulnow)
{

  /* unused parameters */
  (void)ultotal;
  (void)ulnow;

  if(dltotal == 0 || prevprogress == dltotal) {
    return 0;
  }

  if(dload_interrupted) {
    return 1;
  }

  if(handle->dlcb) {
    handle->dlcb((const char*)filename, (long)dlnow, (long)dltotal);
  }

  prevprogress = dlnow;

  return 0;
}

static int curl_gethost(const char *url, char *buffer)
{
  int hostlen;
  char *p;

  if(strncmp(url, "file://", 7) == 0) {
    strcpy(buffer, _("disk"));
  } else {
    p = strstr(url, "//");
    if(!p) {
      return 1;
    }
    p += 2; /* jump over the found // */
    hostlen = strcspn(p, "/");
    if(hostlen > 255) {
      /* buffer overflow imminent */
      _alpm_log(PM_LOG_ERROR, _("buffer overflow detected"));
      return 1;
    }
    snprintf(buffer, hostlen + 1, "%s", p);
  }

  return 0;
}

static int curl_download_internal(const char *url, const char *localpath,
    int force)
{
  int ret = -1;
  FILE *localf = NULL;
  char *destfile, *filename, *tempfile;
  char hostname[256]; /* RFC1123 states applications should support this length */
  struct stat st;
  long httpresp, timecond, remote_time, local_time;
  double remote_size, bytes_dl;
  struct sigaction sig_pipe[2], sig_int[2];

  filename = get_filename(url);
  if(!filename || curl_gethost(url, hostname) != 0) {
    _alpm_log(PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
    RET_ERR(PM_ERR_SERVER_BAD_URL, -1);
  }

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

  /* the curl_easy handle is initialized with the alpm handle, so we only need
   * to reset the curl handle set parameters for each time it's used. */
  curl_easy_reset(handle->curl);
  curl_easy_setopt(handle->curl, CURLOPT_URL, url);
  curl_easy_setopt(handle->curl, CURLOPT_FAILONERROR, 1L);
  curl_easy_setopt(handle->curl, CURLOPT_ENCODING, "deflate, gzip");
  curl_easy_setopt(handle->curl, CURLOPT_CONNECTTIMEOUT, 10L);
  curl_easy_setopt(handle->curl, CURLOPT_FILETIME, 1L);
  curl_easy_setopt(handle->curl, CURLOPT_NOPROGRESS, 0L);
  curl_easy_setopt(handle->curl, CURLOPT_FOLLOWLOCATION, 1L);
  curl_easy_setopt(handle->curl, CURLOPT_PROGRESSFUNCTION, curl_progress);
  curl_easy_setopt(handle->curl, CURLOPT_PROGRESSDATA, filename);

  if(!force && stat(destfile, &st) == 0) {
    /* assume its a sync, so we're starting from scratch. but, only download
     * our local is out of date. */
    local_time = (long)st.st_mtime;
    curl_easy_setopt(handle->curl, CURLOPT_TIMECONDITION, CURL_TIMECOND_IFMODSINCE);
    curl_easy_setopt(handle->curl, CURLOPT_TIMEVALUE, local_time);
  } else if(stat(tempfile, &st) == 0 && st.st_size > 0) {
    /* assume its a partial package download. we do not support resuming of
     * transfers on partially downloaded sync DBs. */
    localf = fopen(tempfile, "ab");
    curl_easy_setopt(handle->curl, CURLOPT_RESUME_FROM, (long)st.st_size);
    _alpm_log(PM_LOG_DEBUG, "tempfile found, attempting continuation");
  }

  /* no destfile and no tempfile. start from scratch */
  if(localf == NULL) {
    localf = fopen(tempfile, "wb");
    if(localf == NULL) {
      goto cleanup;
    }
  }

  /* this has to be set _after_ figuring out which file we're opening */
  curl_easy_setopt(handle->curl, CURLOPT_WRITEDATA, localf);

  /* 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"));

  /* 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);

  /* set initial value of prevprogress to -1 which causes curl_progress() to
   * initialize the progress bar with 0% once. */
  prevprogress = -1;

  /* perform transfer */
  handle->curlerr = curl_easy_perform(handle->curl);

  /* retrieve info about the state of the transfer */
  curl_easy_getinfo(handle->curl, CURLINFO_HTTP_CODE, &httpresp);
  curl_easy_getinfo(handle->curl, CURLINFO_FILETIME, &remote_time);
  curl_easy_getinfo(handle->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &remote_size);
  curl_easy_getinfo(handle->curl, CURLINFO_SIZE_DOWNLOAD, &bytes_dl);
  curl_easy_getinfo(handle->curl, CURLINFO_CONDITION_UNMET, &timecond);

  /* time condition was met and we didn't download anything. we need to
   * clean up the 0 byte .part file that's left behind. */
  if(bytes_dl == 0 && timecond == 1) {
    ret = 1;
    unlink(tempfile);
    goto cleanup;
  }

  if(handle->curlerr == CURLE_ABORTED_BY_CALLBACK) {
    goto cleanup;
  } else if(handle->curlerr != CURLE_OK) {
    pm_errno = PM_ERR_LIBCURL;
    _alpm_log(PM_LOG_ERROR, _("failed retrieving file '%s' from %s : %s\n"),
        filename, hostname, curl_easy_strerror(handle->curlerr));
    unlink(tempfile);
    goto cleanup;
  }

  /* remote_size isn't necessarily the full size of the file, just what the
   * server reported as remaining to download. compare it to what curl reported
   * as actually being transferred during curl_easy_perform() */
  if((remote_size != -1 && bytes_dl != -1) && bytes_dl != remote_size) {
    pm_errno = PM_ERR_RETRIEVE;
    _alpm_log(PM_LOG_ERROR, _("%s appears to be truncated: %jd/%jd bytes\n"),
        filename, (intmax_t)bytes_dl, (intmax_t)remote_size);
    goto cleanup;
  }

  fclose(localf);
  localf = NULL;

  /* set the times on the file to the same as that of the remote file */
  if(remote_time != -1) {
    struct timeval tv[2];
    memset(&tv, 0, sizeof(tv));
    tv[0].tv_sec = tv[1].tv_sec = remote_time;
    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(remote_time != -1) {
      struct timeval tv[2];
      memset(&tv, 0, sizeof(tv));
      tv[0].tv_sec = tv[1].tv_sec = remote_time;
      futimes(fileno(localf), tv);
    }
    fclose(localf);
  }

  /* 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) {
#ifdef HAVE_LIBCURL
    return curl_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: */