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[pacman-ng.git] / 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>
/* the following two are needed for FreeBSD's libfetch */
#include <limits.h> /* PATH_MAX */
#if defined(HAVE_SYS_PARAM_H)
#include <sys/param.h> /* MAXHOSTNAMELEN */
#endif

#ifdef HAVE_LIBFETCH
#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);
}

#ifdef HAVE_LIBFETCH
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 void 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: %jd local_size: %jd compare: %jd\n",
                        (intmax_t)ust.size, (intmax_t)local_size, (intmax_t)(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 %jd\n", (intmax_t)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, (size_t)nread, localf);
                if((nwritten != (size_t)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) {
#ifdef HAVE_LIBFETCH
                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: */