run.c

// Copyright (c) 2019-present Cloud <cloud@txthinking.com>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 3 of the GNU General Public
// License as published by the Free Software Foundation.
//
// 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 <https://www.gnu.org/licenses/>.

#include "joker.h"

void run(int argc, char **argv) {
    pid_t pid1 = fork();
    if (pid1 > 0) {
        exit(0);
    }
    if (pid1 == 0) {
        if (setsid() == -1) {
            syslog(LOG_ERR, "joker: setsid failed");
            exit(1);
        }
        pid_t pid2 = fork();
        if (pid2 > 0) {
            exit(0);
        }
        if (pid2 == 0) {
            chdir("/");
            umask(0);
            int i;
            for (i = 0; i < getdtablesize(); i++) {
                close(i);
            }

            int io[2];
            if (pipe(io) != 0) {
                syslog(LOG_ERR, "joker: create io failed");
                return;
            }
            pid_t pid = fork();
            if (pid == 0) {
#ifdef __linux__
                prctl(PR_SET_PDEATHSIG, SIGHUP);
#endif
                close(io[0]);

                char *l[argc];
                int i = 1;
                for (; i < argc; i++) {
                    l[i - 1] = (char *)malloc(strlen(argv[i]) + 1);
                    l[i - 1] = strcpy(l[i - 1], argv[i]);
                }
                l[i - 1] = NULL;

                dup2(io[1], STDOUT_FILENO);
                dup2(io[1], STDERR_FILENO);
                execvp(l[0], l);

                i = 0;
                for (; i < argc - 1; i++) {
                    free(l[i]);
                }
                close(io[1]);
            }
            if (pid > 0) {
                close(io[1]);

                struct passwd *pw = getpwuid(getuid());

                char *s1 = (char *)malloc(strlen(pw->pw_dir) + 22 * 100 + 7 * 100);
                sprintf(s1, "echo %d > %s/.joker/lastid", pid, pw->pw_dir);
                system(s1);
                free(s1);

                char *s = (char *)malloc(strlen(pw->pw_dir) + 9 * 100 + 7 * 100 + strlen(argv[1]));
                sprintf(s, "%s/.joker/%d.%s", pw->pw_dir, pid, basename(argv[1]));
                FILE *f = fopen(s, "w");
                if (!f) {
                    syslog(LOG_ERR, "joker: fopen failed");
                    free(s);
                    close(io[0]);
                    waitpid(pid, NULL, 0);
                    return;
                }

                for (;;) {
                    char s[1024];
                    int n = read(io[0], s, 1024 - 1);
                    if (n <= 0) {
                        break;
                    }
                    s[n] = 0;
                    int i = fputs(s, f);
                    if (i < 0) {
                        syslog(LOG_ERR, "joker: fputs failed");
                        break;
                    }
                    fflush(f);
                }
                close(io[0]);
                fclose(f);
                chmod(s, 0666);
                free(s);
                waitpid(pid, NULL, 0);
            }
        }
    }
}