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pacman/lib/libalpm/dload.c

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/*
* 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>
download: major refactor to address lingering issues Sorry for this being such a huge patch, but I believe it is necessary for quite a few reasons which I will attempt to explain herein. I've been mulling this over for a while, but wasn't super happy with making the download interface more complex. Instead, if we carefully order things in the internal download code, we can actually make the interface simpler. 1. FS#15657 - This involves `name.db.tar.gz.part` files being left around the filesystem, and then causing all sorts of issues when someone attempts to rerun the operation they canceled. We need to ensure that if we resume a download, we are resuming it on exactly the same file; if we cannot be almost postive of that then we need to start over. 2. http://www.mail-archive.com/pacman-dev@archlinux.org/msg03536.html - Here we have a lighttpd bug to ruin the day. If we send both a Range: header and If-Modified-Since: header across the wire in a GET request, lighttpd doesn't do what we want in several cases. If the file hadn't been modified, it returns a '304 Not Modified' instead of a '206 Partial Content'. We need to do a stat (e.g. HEAD in HTTP terms) operation here, and the proceed accordingly based off the values we get back from it. 3. The mtime stuff was rather ugly, and relied on the called function to write back to a passed in reference, which isn't the greatest. Instead, use the power of the filesystem to contain this info. Every file downloaded internally is now carefully timestamped with the remote file time. This should allow the resume logic to work. In order to guarantee this, we need to implement a signal handler that catches interrupts, notifies the running code, and causes it to set the mtimes on the file. It then rethrows the signal so the pacman signal handler (or any frontend) works as expected. 4. We did a lot of funky stuff in trying to track the DB last modified time. It is a lot easier to just keep the downloaded DB file around and track the time on that rather than in a funky dot file. It also kills a lot of code. 5. For GPG verification of the databases down the road, we are going to need the DB file around for at least a short bit of time anyway, so this gets us closer to that. Signed-off-by: Dan McGee <dan@archlinux.org> [Xav: fixed printf with off_t] Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
2009-11-12 00:39:26 -05:00
#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"
#ifdef HAVE_LIBCURL
static double prevprogress; /* last download amount */
#endif
static const char *get_filename(const char *url)
{
char *filename = strrchr(url, '/');
if(filename != NULL) {
filename++;
}
return filename;
}
#ifdef HAVE_LIBCURL
static char *get_fullpath(const char *path, const char *filename,
const char *suffix)
{
char *filepath;
/* len = localpath len + filename len + suffix len + null */
size_t len = strlen(path) + strlen(filename) + strlen(suffix) + 1;
CALLOC(filepath, len, sizeof(char), return NULL);
snprintf(filepath, len, "%s%s%s", path, filename, suffix);
return filepath;
}
#define check_stop() if(dload_interrupted) { ret = -1; goto cleanup; }
enum sighandlers { OLD = 0, NEW = 1 };
static int dload_interrupted;
static void inthandler(int UNUSED signum)
{
dload_interrupted = 1;
}
download: major refactor to address lingering issues Sorry for this being such a huge patch, but I believe it is necessary for quite a few reasons which I will attempt to explain herein. I've been mulling this over for a while, but wasn't super happy with making the download interface more complex. Instead, if we carefully order things in the internal download code, we can actually make the interface simpler. 1. FS#15657 - This involves `name.db.tar.gz.part` files being left around the filesystem, and then causing all sorts of issues when someone attempts to rerun the operation they canceled. We need to ensure that if we resume a download, we are resuming it on exactly the same file; if we cannot be almost postive of that then we need to start over. 2. http://www.mail-archive.com/pacman-dev@archlinux.org/msg03536.html - Here we have a lighttpd bug to ruin the day. If we send both a Range: header and If-Modified-Since: header across the wire in a GET request, lighttpd doesn't do what we want in several cases. If the file hadn't been modified, it returns a '304 Not Modified' instead of a '206 Partial Content'. We need to do a stat (e.g. HEAD in HTTP terms) operation here, and the proceed accordingly based off the values we get back from it. 3. The mtime stuff was rather ugly, and relied on the called function to write back to a passed in reference, which isn't the greatest. Instead, use the power of the filesystem to contain this info. Every file downloaded internally is now carefully timestamped with the remote file time. This should allow the resume logic to work. In order to guarantee this, we need to implement a signal handler that catches interrupts, notifies the running code, and causes it to set the mtimes on the file. It then rethrows the signal so the pacman signal handler (or any frontend) works as expected. 4. We did a lot of funky stuff in trying to track the DB last modified time. It is a lot easier to just keep the downloaded DB file around and track the time on that rather than in a funky dot file. It also kills a lot of code. 5. For GPG verification of the databases down the road, we are going to need the DB file around for at least a short bit of time anyway, so this gets us closer to that. Signed-off-by: Dan McGee <dan@archlinux.org> [Xav: fixed printf with off_t] Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
2009-11-12 00:39:26 -05:00
static int curl_progress(void *file, double dltotal, double dlnow,
double UNUSED ultotal, double UNUSED ulnow)
{
struct fileinfo *dlfile = (struct fileinfo *)file;
double current_size, total_size;
/* SIGINT sent, abort by alerting curl */
if(dload_interrupted) {
return 1;
}
/* none of what follows matters if the front end has no callback */
if(dlfile->handle->dlcb == NULL) {
return 0;
}
current_size = dlfile->initial_size + dlnow;
total_size = dlfile->initial_size + dltotal;
if(DOUBLE_EQ(dltotal, 0) || DOUBLE_EQ(prevprogress, total_size)) {
return 0;
}
/* initialize the progress bar here to avoid displaying it when
* a repo is up to date and nothing gets downloaded */
if(DOUBLE_EQ(prevprogress, 0)) {
dlfile->handle->dlcb(dlfile->filename, 0, (long)dltotal);
}
dlfile->handle->dlcb(dlfile->filename, (long)current_size, (long)total_size);
prevprogress = current_size;
return 0;
}
static int curl_gethost(const char *url, char *buffer)
{
size_t 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 */
return 1;
}
snprintf(buffer, hostlen + 1, "%s", p);
}
return 0;
}
static int utimes_long(const char *path, long time)
{
if(time != -1) {
struct timeval tv[2];
memset(&tv, 0, sizeof(tv));
tv[0].tv_sec = tv[1].tv_sec = time;
return utimes(path, tv);
}
return 0;
}
static int curl_download_internal(pmhandle_t *handle,
const char *url, const char *localpath,
int force, int allow_resume, int errors_ok)
{
int ret = -1;
FILE *localf = NULL;
const char *useragent;
const char *open_mode = "wb";
char *destfile, *tempfile;
/* RFC1123 states applications should support this length */
char hostname[256];
char error_buffer[CURL_ERROR_SIZE];
struct stat st;
long timecond, remote_time;
double remote_size, bytes_dl;
struct sigaction sig_pipe[2], sig_int[2];
struct fileinfo dlfile;
dlfile.handle = handle;
dlfile.initial_size = 0.0;
dlfile.filename = get_filename(url);
if(!dlfile.filename || curl_gethost(url, hostname) != 0) {
_alpm_log(handle, PM_LOG_ERROR, _("url '%s' is invalid\n"), url);
RET_ERR(handle, PM_ERR_SERVER_BAD_URL, -1);
}
destfile = get_fullpath(localpath, dlfile.filename, "");
tempfile = get_fullpath(localpath, dlfile.filename, ".part");
if(!destfile || !tempfile) {
goto cleanup;
}
error_buffer[0] = '\0';
/* 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_ERRORBUFFER, error_buffer);
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, (void *)&dlfile);
curl_easy_setopt(handle->curl, CURLOPT_LOW_SPEED_LIMIT, 1024L);
curl_easy_setopt(handle->curl, CURLOPT_LOW_SPEED_TIME, 10L);
useragent = getenv("HTTP_USER_AGENT");
if(useragent != NULL) {
curl_easy_setopt(handle->curl, CURLOPT_USERAGENT, useragent);
}
if(!allow_resume && !force && stat(destfile, &st) == 0) {
/* start from scratch, but only download if our local is out of date. */
curl_easy_setopt(handle->curl, CURLOPT_TIMECONDITION, CURL_TIMECOND_IFMODSINCE);
curl_easy_setopt(handle->curl, CURLOPT_TIMEVALUE, (long)st.st_mtime);
} else if(stat(tempfile, &st) == 0 && allow_resume) {
/* a previous partial download exists, resume from end of file. */
open_mode = "ab";
curl_easy_setopt(handle->curl, CURLOPT_RESUME_FROM, (long)st.st_size);
_alpm_log(handle, PM_LOG_DEBUG, "tempfile found, attempting continuation");
dlfile.initial_size = (double)st.st_size;
}
localf = fopen(tempfile, open_mode);
if(localf == NULL) {
goto cleanup;
}
curl_easy_setopt(handle->curl, CURLOPT_WRITEDATA, localf);
/* 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);
/* Progress 0 - initialize */
prevprogress = 0;
/* perform transfer */
handle->curlerr = curl_easy_perform(handle->curl);
/* was it a success? */
if(handle->curlerr == CURLE_ABORTED_BY_CALLBACK) {
goto cleanup;
} else if(handle->curlerr != CURLE_OK) {
if(!errors_ok) {
handle->pm_errno = PM_ERR_LIBCURL;
_alpm_log(handle, PM_LOG_ERROR, _("failed retrieving file '%s' from %s : %s\n"),
dlfile.filename, hostname, error_buffer);
} else {
_alpm_log(handle, PM_LOG_DEBUG, "failed retrieving file '%s' from %s : %s\n",
dlfile.filename, hostname, error_buffer);
}
unlink(tempfile);
goto cleanup;
}
/* retrieve info about the state of the transfer */
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(timecond == 1 && DOUBLE_EQ(bytes_dl, 0)) {
ret = 1;
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(!DOUBLE_EQ(remote_size, -1) && !DOUBLE_EQ(bytes_dl, -1) &&
!DOUBLE_EQ(bytes_dl, remote_size)) {
handle->pm_errno = PM_ERR_RETRIEVE;
_alpm_log(handle, PM_LOG_ERROR, _("%s appears to be truncated: %jd/%jd bytes\n"),
dlfile.filename, (intmax_t)bytes_dl, (intmax_t)remote_size);
goto cleanup;
}
ret = 0;
cleanup:
if(localf != NULL) {
fclose(localf);
utimes_long(tempfile, remote_time);
}
if(ret == 0) {
rename(tempfile, destfile);
}
FREE(tempfile);
FREE(destfile);
/* 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
/** Download a file given by a URL to a local directory.
* Does not overwrite an existing file if the download fails.
* @param handle the context handle
* @param url the file's URL
* @param localpath the directory to save the file in
* @param force force download even if there is an up-to-date local copy
* @param allow_resume allow a partial download to be resumed
* @param errors_ok do not log errors (but still return them)
* @return 0 on success, -1 on error (pm_errno is set accordingly if errors_ok == 0)
*/
int _alpm_download(pmhandle_t *handle, const char *url, const char *localpath,
int force, int allow_resume, int errors_ok)
{
if(handle->fetchcb == NULL) {
#ifdef HAVE_LIBCURL
return curl_download_internal(handle, url, localpath,
force, allow_resume, errors_ok);
#else
RET_ERR(handle, PM_ERR_EXTERNAL_DOWNLOAD, -1);
#endif
} else {
download: major refactor to address lingering issues Sorry for this being such a huge patch, but I believe it is necessary for quite a few reasons which I will attempt to explain herein. I've been mulling this over for a while, but wasn't super happy with making the download interface more complex. Instead, if we carefully order things in the internal download code, we can actually make the interface simpler. 1. FS#15657 - This involves `name.db.tar.gz.part` files being left around the filesystem, and then causing all sorts of issues when someone attempts to rerun the operation they canceled. We need to ensure that if we resume a download, we are resuming it on exactly the same file; if we cannot be almost postive of that then we need to start over. 2. http://www.mail-archive.com/pacman-dev@archlinux.org/msg03536.html - Here we have a lighttpd bug to ruin the day. If we send both a Range: header and If-Modified-Since: header across the wire in a GET request, lighttpd doesn't do what we want in several cases. If the file hadn't been modified, it returns a '304 Not Modified' instead of a '206 Partial Content'. We need to do a stat (e.g. HEAD in HTTP terms) operation here, and the proceed accordingly based off the values we get back from it. 3. The mtime stuff was rather ugly, and relied on the called function to write back to a passed in reference, which isn't the greatest. Instead, use the power of the filesystem to contain this info. Every file downloaded internally is now carefully timestamped with the remote file time. This should allow the resume logic to work. In order to guarantee this, we need to implement a signal handler that catches interrupts, notifies the running code, and causes it to set the mtimes on the file. It then rethrows the signal so the pacman signal handler (or any frontend) works as expected. 4. We did a lot of funky stuff in trying to track the DB last modified time. It is a lot easier to just keep the downloaded DB file around and track the time on that rather than in a funky dot file. It also kills a lot of code. 5. For GPG verification of the databases down the road, we are going to need the DB file around for at least a short bit of time anyway, so this gets us closer to that. Signed-off-by: Dan McGee <dan@archlinux.org> [Xav: fixed printf with off_t] Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
2009-11-12 00:39:26 -05:00
int ret = handle->fetchcb(url, localpath, force);
if(ret == -1 && !errors_ok) {
RET_ERR(handle, PM_ERR_EXTERNAL_DOWNLOAD, -1);
}
return ret;
}
}
/** Fetch a remote pkg. */
char SYMEXPORT *alpm_fetch_pkgurl(pmhandle_t *handle, const char *url)
{
char *filepath;
const char *filename, *cachedir;
int ret;
CHECK_HANDLE(handle, return NULL);
filename = get_filename(url);
/* find a valid cache dir to download to */
cachedir = _alpm_filecache_setup(handle);
/* download the file */
ret = _alpm_download(handle, url, cachedir, 0, 1, 0);
if(ret == -1) {
_alpm_log(handle, PM_LOG_WARNING, _("failed to download %s\n"), url);
return NULL;
}
_alpm_log(handle, PM_LOG_DEBUG, "successfully downloaded %s\n", url);
/* attempt to download the signature */
if(ret == 0 && (handle->sigverify == PM_PGP_VERIFY_ALWAYS ||
handle->sigverify == PM_PGP_VERIFY_OPTIONAL)) {
char *sig_url;
size_t len;
int errors_ok = (handle->sigverify == PM_PGP_VERIFY_OPTIONAL);
len = strlen(url) + 5;
CALLOC(sig_url, len, sizeof(char), RET_ERR(handle, PM_ERR_MEMORY, NULL));
snprintf(sig_url, len, "%s.sig", url);
ret = _alpm_download(handle, sig_url, cachedir, 1, 0, errors_ok);
if(ret == -1 && !errors_ok) {
_alpm_log(handle, PM_LOG_WARNING, _("failed to download %s\n"), sig_url);
/* Warn now, but don't return NULL. We will fail later during package
* load time. */
} else if(ret == 0) {
_alpm_log(handle, PM_LOG_DEBUG, "successfully downloaded %s\n", sig_url);
}
FREE(sig_url);
}
/* we should be able to find the file the second time around */
filepath = _alpm_filecache_find(handle, filename);
return filepath;
}
/* vim: set ts=2 sw=2 noet: */