server.c

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/*
 *  server.c
 *
 *  Copyright (c) 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 <stdlib.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#include <limits.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <download.h>

/* libalpm */
#include "server.h"
#include "alpm_list.h"
#include "error.h"
#include "log.h"
#include "alpm.h"
#include "util.h"
#include "handle.h"
#include "package.h"

pmserver_t *_alpm_server_new(const char *url)
{
    struct url *u;
    pmserver_t *server;

    ALPM_LOG_FUNC;

    CALLOC(server, 1, sizeof(pmserver_t), RET_ERR(PM_ERR_MEMORY, NULL));

    u = downloadParseURL(url);
    if(!u) {
        _alpm_log(PM_LOG_ERROR, _("url '%s' is invalid, ignoring\n"), url);
        RET_ERR(PM_ERR_SERVER_BAD_URL, NULL);
    }
    if(strlen(u->scheme) == 0) {
        _alpm_log(PM_LOG_WARNING, _("url scheme not specified, assuming http\n"));
        strcpy(u->scheme, "http");
    }

    if(strcmp(u->scheme,"ftp") == 0 && strlen(u->user) == 0) {
        strcpy(u->user, "anonymous");
        strcpy(u->pwd, "libalpm@guest");
    }

    /* remove trailing slashes, just to clean up the rest of the code */
    for(int i = strlen(u->doc) - 1; u->doc[i] == '/'; --i)
        u->doc[i] = '\0';

  server->s_url = u;

    return server;
}

void _alpm_server_free(pmserver_t *server)
{
    ALPM_LOG_FUNC;

    if(server == NULL) {
        return;
    }

    /* free memory */
    downloadFreeURL(server->s_url);
    FREE(server);
}

/* remove filename info from "s_url->doc" and return it */
static char *strip_filename(pmserver_t *server)
{
    char *p = NULL, *fname = NULL;
    if(!server) {
        return(NULL);
    }

    p = strrchr(server->s_url->doc, '/');
    if(p && *(++p)) {
        fname = strdup(p);
        _alpm_log(PM_LOG_DEBUG, "stripping '%s' from '%s'\n",
                fname, server->s_url->doc);
        *p = 0;
    }

    /* s_url->doc now contains ONLY path information.  return value
     * if the file information from the original URL */
    return(fname);
}

/* Return a 'struct url' for this server, for downloading 'filename'. */
static struct url *url_for_file(pmserver_t *server, const char *filename)
{
    struct url *ret = NULL;
    char *doc = NULL;
    int doclen = 0;

    doclen = strlen(server->s_url->doc) + strlen(filename) + 2;
    CALLOC(doc, doclen, sizeof(char), RET_ERR(PM_ERR_MEMORY, NULL));

    snprintf(doc, doclen, "%s/%s", server->s_url->doc, filename);
    ret = downloadMakeURL(server->s_url->scheme,
                                                server->s_url->host,
                                                server->s_url->port,
                                                doc,
                                                server->s_url->user,
                                                server->s_url->pwd);
    FREE(doc);
    return(ret);
}

/*
 * Download a list of files from a list of servers
 *   - if one server fails, we try the next one in the list
 *   - if *dl_total is non-NULL, then it will be used as the starting
 *     download amount when TotalDownload is set. It will also be
 *     set to the final download amount for the calling function to use.
 *   - totalsize is the total download size for use when TotalDownload
 *     is set. Use 0 if the total download size is not known.
 *
 * RETURN:  0 for successful download, 1 on error
 */
int _alpm_downloadfiles(alpm_list_t *servers, const char *localpath,
        alpm_list_t *files, int *dl_total, unsigned long totalsize)
{
    return(_alpm_downloadfiles_forreal(servers, localpath, files, 0, NULL,
                dl_total, totalsize));
}

/*
 * This is the real downloadfiles, used directly by sync_synctree() to check
 * modtimes on remote files.
 *   - if mtime1 is non-NULL, then only download files if they are different
 *     than mtime1.
 *   - if *mtime2 is non-NULL, it will be filled with the mtime of the remote
 *     file.
 *   - if *dl_total is non-NULL, then it will be used as the starting
 *     download amount when TotalDownload is set. It will also be
 *     set to the final download amount for the calling function to use.
 *   - totalsize is the total download size for use when TotalDownload
 *     is set. Use 0 if the total download size is not known.
 *
 * RETURN:  0 for successful download
 *          1 if the mtimes are identical
 *         -1 on error
 */
int _alpm_downloadfiles_forreal(alpm_list_t *servers, const char *localpath,
    alpm_list_t *files, time_t mtime1, time_t *mtime2, int *dl_total,
    unsigned long totalsize)
{
    int dl_thisfile = 0;
    alpm_list_t *lp;
    int done = 0;
    alpm_list_t *complete = NULL;
    alpm_list_t *i;

    ALPM_LOG_FUNC;

    if(files == NULL) {
        return(0);
    }

    for(i = servers; i && !done; i = i->next) {
        pmserver_t *server = i->data;

        /* get each file in the list */
        for(lp = files; lp; lp = lp->next) {
            struct url *fileurl = NULL;
            char realfile[PATH_MAX];
            char output[PATH_MAX];
            char *fn = (char *)lp->data;
            char *pkgname;

            fileurl = url_for_file(server, fn);
            if(!fileurl) {
                return(-1);
            }

            /* pass the raw filename for passing to the callback function */
            STRDUP(pkgname, fn, (void)0);
            _alpm_log(PM_LOG_DEBUG, "using '%s' for download progress\n", pkgname);

            snprintf(realfile, PATH_MAX, "%s%s", localpath, fn);
            snprintf(output, PATH_MAX, "%s%s.part", localpath, fn);

            if(alpm_list_find_str(complete, fn)) {
                continue;
            }

            if(!handle->xfercommand || !strcmp(fileurl->scheme, "file")) {
                FILE *dlf, *localf = NULL;
                struct url_stat ust;
                struct stat st;
                int chk_resume = 0;

                if(stat(output, &st) == 0 && st.st_size > 0) {
                    _alpm_log(PM_LOG_DEBUG, "existing file found, using it\n");
                    fileurl->offset = (off_t)st.st_size;
                    dl_thisfile = st.st_size;
                    if (dl_total != NULL) {
                        *dl_total += st.st_size;
                    }
                    localf = fopen(output, "a");
                    chk_resume = 1;
                } else {
                    fileurl->offset = (off_t)0;
                    dl_thisfile = 0;
                }

                /* libdownload does not reset the error code, reset it in
                 * the case of previous errors */
                downloadLastErrCode = 0;

                /* 10s timeout - TODO make a config option */
                downloadTimeout = 10000;

                dlf = downloadXGet(fileurl, &ust, (handle->nopassiveftp ? "" : "p"));

                if(downloadLastErrCode != 0 || dlf == NULL) {
                    const char *host = _("disk");
                    if(strcmp(SCHEME_FILE, fileurl->scheme) != 0) {
                        host = fileurl->host;
                    }
                    _alpm_log(PM_LOG_ERROR, _("failed retrieving file '%s' from %s : %s\n"),
                                        fn, host, downloadLastErrString);
                    if(localf != NULL) {
                        fclose(localf);
                    }
                    /* try the next server */
                    downloadFreeURL(fileurl);
                    continue;
                } else {
                        _alpm_log(PM_LOG_DEBUG, "connected to %s successfully\n", fileurl->host);
                }

                if(ust.mtime && mtime1 && ust.mtime == mtime1) {
                    _alpm_log(PM_LOG_DEBUG, "mtimes are identical, skipping %s\n", fn);
                    complete = alpm_list_add(complete, fn);
                    if(localf != NULL) {
                        fclose(localf);
                    }
                    if(dlf != NULL) {
                        fclose(dlf);
                    }
                    downloadFreeURL(fileurl);
                    return(1);
                }

                if(ust.mtime && mtime2) {
                    *mtime2 = ust.mtime;
                }

                if(chk_resume && fileurl->offset == 0) {
                    _alpm_log(PM_LOG_WARNING, _("cannot resume download, starting over\n"));
                    if(localf != NULL) {
                        fclose(localf);
                        localf = NULL;
                    }
                }

                if(localf == NULL) {
                    _alpm_rmrf(output);
                    fileurl->offset = (off_t)0;
                    dl_thisfile = 0;
                    localf = fopen(output, "w");
                    if(localf == NULL) { /* still null? */
                        _alpm_log(PM_LOG_ERROR, _("cannot write to file '%s'\n"), output);
                        if(dlf != NULL) {
                            fclose(dlf);
                        }
                        downloadFreeURL(fileurl);
                        return(-1);
                    }
                }

                /* Progress 0 - initialize */
                if(handle->dlcb) {
                    handle->dlcb(pkgname, 0, ust.size, dl_total ? *dl_total : 0,
                            totalsize);
                }

                int nread = 0;
                char buffer[PM_DLBUF_LEN];
                while((nread = fread(buffer, 1, PM_DLBUF_LEN, dlf)) > 0) {
                    if(ferror(dlf)) {
                        _alpm_log(PM_LOG_ERROR, _("error downloading '%s': %s\n"),
                                            fn, downloadLastErrString);
                        fclose(localf);
                        fclose(dlf);
                        downloadFreeURL(fileurl);
                        return(-1);
                    }

                    int nwritten = 0;
                    while(nwritten < nread) {
                        nwritten += fwrite(buffer, 1, (nread - nwritten), localf);
                        if(ferror(localf)) {
                            _alpm_log(PM_LOG_ERROR, _("error writing to file '%s': %s\n"),
                                                realfile, strerror(errno));
                            fclose(localf);
                            fclose(dlf);
                            downloadFreeURL(fileurl);
                            return(-1);
                        }
                    }

                    if(nwritten != nread) {

                    }
                    dl_thisfile += nread;
                    if (dl_total != NULL) {
                        *dl_total += nread;
                    }

                    if(handle->dlcb) {
                        handle->dlcb(pkgname, dl_thisfile, ust.size,
                                dl_total ? *dl_total : 0, totalsize);
                    }
                }

                downloadFreeURL(fileurl);
                fclose(localf);
                fclose(dlf);
                rename(output, realfile);
                complete = alpm_list_add(complete, fn);
            } else {
                int ret;
                int usepart = 0;
                char *ptr1, *ptr2;
                char origCmd[PATH_MAX];
                char parsedCmd[PATH_MAX] = "";
                char url[PATH_MAX];
                char cwd[PATH_MAX];

                /* build the full download url */
                snprintf(url, PATH_MAX, "%s://%s%s", fileurl->scheme,
                        fileurl->host, fileurl->doc);
                /* we don't need this anymore */
                downloadFreeURL(fileurl);

                /* replace all occurrences of %o with fn.part */
                strncpy(origCmd, handle->xfercommand, sizeof(origCmd));
                ptr1 = origCmd;
                while((ptr2 = strstr(ptr1, "%o"))) {
                    usepart = 1;
                    ptr2[0] = '\0';
                    strcat(parsedCmd, ptr1);
                    strcat(parsedCmd, output);
                    ptr1 = ptr2 + 2;
                }
                strcat(parsedCmd, ptr1);
                /* replace all occurrences of %u with the download URL */
                strncpy(origCmd, parsedCmd, sizeof(origCmd));
                parsedCmd[0] = '\0';
                ptr1 = origCmd;
                while((ptr2 = strstr(ptr1, "%u"))) {
                    ptr2[0] = '\0';
                    strcat(parsedCmd, ptr1);
                    strcat(parsedCmd, url);
                    ptr1 = ptr2 + 2;
                }
                strcat(parsedCmd, ptr1);
                /* cwd to the download directory */
                getcwd(cwd, PATH_MAX);
                if(chdir(localpath)) {
                    _alpm_log(PM_LOG_WARNING, _("could not chdir to %s\n"), localpath);
                    return(PM_ERR_CONNECT_FAILED);
                }
                /* execute the parsed command via /bin/sh -c */
                _alpm_log(PM_LOG_DEBUG, "running command: %s\n", parsedCmd);
                ret = system(parsedCmd);
                if(ret == -1) {
                    _alpm_log(PM_LOG_WARNING, _("running XferCommand: fork failed!\n"));
                    return(PM_ERR_FORK_FAILED);
                } else if(ret != 0) {
                    /* download failed */
                    _alpm_log(PM_LOG_DEBUG, "XferCommand command returned non-zero status code (%d)\n", ret);
                } else {
                    /* download was successful */
                    complete = alpm_list_add(complete, fn);
                    if(usepart) {
                        rename(output, realfile);
                    }
                }
                chdir(cwd);
            }
            FREE(pkgname);
        }

        if(alpm_list_count(complete) == alpm_list_count(files)) {
            done = 1;
        }
    }
    alpm_list_free(complete);

    return(done ? 0 : -1);
}

/** 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)
{
    pmserver_t *server;
    char *filename, *filepath;
    const char *cachedir;

    ALPM_LOG_FUNC;

    if(strstr(url, "://") == NULL) {
        _alpm_log(PM_LOG_DEBUG, "Invalid URL passed to alpm_fetch_pkgurl\n");
        return(NULL);
    }

    server = _alpm_server_new(url);
    if(!server) {
        return(NULL);
    }

    /* strip path information from the filename */
    filename = strip_filename(server);
    if(!filename) {
        _alpm_log(PM_LOG_ERROR, _("URL does not contain a file for download\n"));
        return(NULL);
    }

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

    /* TODO this seems like needless complexity just to download one file */
    alpm_list_t *servers = alpm_list_add(NULL, server);
    alpm_list_t *files = alpm_list_add(NULL, filename);

    /* download the file */
    if(_alpm_downloadfiles(servers, cachedir, files, NULL, 0)) {
        _alpm_log(PM_LOG_WARNING, _("failed to download %s\n"), url);
        return(NULL);
    }
    _alpm_log(PM_LOG_DEBUG, "successfully downloaded %s\n", filename);
    alpm_list_free(files);
    alpm_list_free(servers);
    _alpm_server_free(server);

    /* 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: */

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