source: MondoRescue/branches/3.3/mindi-busybox/mailutils/mail.c@ 3723

/* vi: set sw=4 ts=4: */
/*
 * helper routines
 *
 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
#include "libbb.h"
#include "mail.h"

static void kill_helper(void)
{
    if (G.helper_pid > 0) {
        kill(G.helper_pid, SIGTERM);
        G.helper_pid = 0;
    }
}

// generic signal handler
static void signal_handler(int signo)
{
#define err signo
    if (SIGALRM == signo) {
        kill_helper();
        bb_error_msg_and_die("timed out");
    }

    // SIGCHLD. reap zombies
    if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0) {
        if (WIFSIGNALED(err))
            bb_error_msg_and_die("helper killed by signal %u", WTERMSIG(err));
        if (WIFEXITED(err)) {
            G.helper_pid = 0;
            if (WEXITSTATUS(err))
                bb_error_msg_and_die("helper exited (%u)", WEXITSTATUS(err));
        }
    }
#undef err
}

void FAST_FUNC launch_helper(const char **argv)
{
    // setup vanilla unidirectional pipes interchange
    int i;
    int pipes[4];

    xpipe(pipes);
    xpipe(pipes + 2);

    // NB: handler must be installed before vfork
    bb_signals(0
        + (1 << SIGCHLD)
        + (1 << SIGALRM)
        , signal_handler);

    G.helper_pid = xvfork();

    i = (!G.helper_pid) * 2; // for parent:0, for child:2
    close(pipes[i + 1]);     // 1 or 3 - closing one write end
    close(pipes[2 - i]);     // 2 or 0 - closing one read end
    xmove_fd(pipes[i], STDIN_FILENO);      // 0 or 2 - using other read end
    xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - using other write end
    // End result:
    // parent stdout [3] -> child stdin [2]
    // child stdout [1] -> parent stdin [0]

    if (!G.helper_pid) {
        // child: try to execute connection helper
        // NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
        BB_EXECVP_or_die((char**)argv);
    }

    // parent
    // check whether child is alive
    //redundant:signal_handler(SIGCHLD);
    // child seems OK -> parent goes on
    atexit(kill_helper);
}

char* FAST_FUNC send_mail_command(const char *fmt, const char *param)
{
    char *msg;
    if (timeout)
        alarm(timeout);
    msg = (char*)fmt;
    if (fmt) {
        msg = xasprintf(fmt, param);
        if (verbose)
            bb_error_msg("send:'%s'", msg);
        printf("%s\r\n", msg);
    }
    fflush_all();
    return msg;
}

// NB: parse_url can modify url[] (despite const), but only if '@' is there
/*
static char* FAST_FUNC parse_url(char *url, char **user, char **pass)
{
    // parse [user[:pass]@]host
    // return host
    char *s = strchr(url, '@');
    *user = *pass = NULL;
    if (s) {
        *s++ = '\0';
        *user = url;
        url = s;
        s = strchr(*user, ':');
        if (s) {
            *s++ = '\0';
            *pass = s;
        }
    }
    return url;
}
*/

void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
{
    enum {
        SRC_BUF_SIZE = 57,  /* This *MUST* be a multiple of 3 */
        DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
    };
#define src_buf text
    char src[SRC_BUF_SIZE];
    FILE *fp = fp;
    ssize_t len = len;
    char dst_buf[DST_BUF_SIZE + 1];

    if (fname) {
        fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
        src_buf = src;
    } else if (text) {
        // though we do not call uuencode(NULL, NULL) explicitly
        // still we do not want to break things suddenly
        len = strlen(text);
    } else
        return;

    while (1) {
        size_t size;
        if (fname) {
            size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
            if ((ssize_t)size < 0)
                bb_perror_msg_and_die(bb_msg_read_error);
        } else {
            size = len;
            if (len > SRC_BUF_SIZE)
                size = SRC_BUF_SIZE;
        }
        if (!size)
            break;
        // encode the buffer we just read in
        bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
        if (fname) {
            puts(eol);
        } else {
            src_buf += size;
            len -= size;
        }
        fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
    }
    if (fname && NOT_LONE_DASH(fname))
        fclose(fp);
#undef src_buf
}

/*
 * get username and password from a file descriptor
 */
void FAST_FUNC get_cred_or_die(int fd)
{
    if (isatty(fd)) {
        G.user = xstrdup(bb_ask(fd, /* timeout: */ 0, "User: "));
        G.pass = xstrdup(bb_ask(fd, /* timeout: */ 0, "Password: "));
    } else {
        G.user = xmalloc_reads(fd, /* maxsize: */ NULL);
        G.pass = xmalloc_reads(fd, /* maxsize: */ NULL);
    }
    if (!G.user || !*G.user || !G.pass)
        bb_error_msg_and_die("no username or password");
}