1 files changed, 192 insertions, 0 deletions

diff --git a/src/lib/common.c b/src/lib/common.c
new file mode 100644
index 000000000..6d928abbb
--- /dev/null
+++ b/src/lib/common.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2014, 2015 netblue30 (netblue30@yahoo.com)
+ *
+ * This file is part of firejail project
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/prctl.h>
+#include <signal.h>
+#include <dirent.h>
+#include <string.h>
+#include "../include/common.h"
+
+int join_namespace(pid_t pid, char *type) {
+        char *path;
+        if (asprintf(&path, "/proc/%u/ns/%s", pid, type) == -1)
+                errExit("asprintf");
+        
+        int fd = open(path, O_RDONLY);
+        if (fd < 0) {
+                free(path);
+                fprintf(stderr, "Error: cannot open /proc/%u/ns/%s.\n", pid, type);
+                return -1;
+        }
+
+        if (syscall(__NR_setns, fd, 0) < 0) {
+                free(path);
+                fprintf(stderr, "Error: cannot join namespace %s.\n", type);
+                close(fd);
+                return -1;
+        }
+
+        close(fd);
+        free(path);
+        return 0;
+}
+
+// return 1 if error
+int name2pid(const char *name, pid_t *pid) {
+        pid_t parent = getpid();
+        
+        DIR *dir;
+        if (!(dir = opendir("/proc"))) {
+                // sleep 2 seconds and try again
+                sleep(2);
+                if (!(dir = opendir("/proc"))) {
+                        fprintf(stderr, "Error: cannot open /proc directory\n");
+                        exit(1);
+                }
+        }
+        
+        struct dirent *entry;
+        char *end;
+        while ((entry = readdir(dir))) {
+                pid_t newpid = strtol(entry->d_name, &end, 10);
+                if (end == entry->d_name || *end)
+                        continue;
+                if (newpid == parent)
+                        continue;
+
+                // check if this is a firejail executable
+                char *comm = pid_proc_comm(newpid);
+                if (comm) {
+                        // remove \n
+                        char *ptr = strchr(comm, '\n');
+                        if (ptr)
+                                *ptr = '\0';
+                        if (strcmp(comm, "firejail")) {
+                                free(comm);
+                                continue;
+                        }
+                        free(comm);
+                }
+                
+                char *cmd = pid_proc_cmdline(newpid);
+                if (cmd) {
+                        // mark the end of the name
+                        char *ptr = strstr(cmd, "--name=");
+                        char *start = ptr;
+                        if (!ptr) {
+                                free(cmd);
+                                continue;
+                        }
+                        while (*ptr != ' ' && *ptr != '\t' && *ptr != '\0')
+                                ptr++;
+                        *ptr = '\0';
+                        int rv = strcmp(start + 7, name);
+                        if (rv == 0) {
+                                free(cmd);
+                                *pid = newpid;
+                                closedir(dir);
+                                return 0;
+                        }
+                        free(cmd);
+                }
+        }
+        closedir(dir);
+        return 1;
+}
+
+#define BUFLEN 4096
+char *pid_proc_comm(const pid_t pid) {
+        // open /proc/pid/cmdline file
+        char *fname;
+        int fd;
+        if (asprintf(&fname, "/proc/%d//comm", pid) == -1)
+                return NULL;
+        if ((fd = open(fname, O_RDONLY)) < 0) {
+                free(fname);
+                return NULL;
+        }
+        free(fname);
+
+        // read file
+        unsigned char buffer[BUFLEN];
+        ssize_t len;
+        if ((len = read(fd, buffer, sizeof(buffer) - 1)) <= 0) {
+                close(fd);
+                return NULL;
+        }
+        buffer[len] = '\0';
+        close(fd);
+
+        // return a malloc copy of the command line
+        char *rv = strdup((char *) buffer);
+        if (strlen(rv) == 0) {
+                free(rv);
+                return NULL;
+        }
+        return rv;
+}
+
+char *pid_proc_cmdline(const pid_t pid) {
+        // open /proc/pid/cmdline file
+        char *fname;
+        int fd;
+        if (asprintf(&fname, "/proc/%d/cmdline", pid) == -1)
+                return NULL;
+        if ((fd = open(fname, O_RDONLY)) < 0) {
+                free(fname);
+                return NULL;
+        }
+        free(fname);
+
+        // read file
+        unsigned char buffer[BUFLEN];
+        ssize_t len;
+        if ((len = read(fd, buffer, sizeof(buffer) - 1)) <= 0) {
+                close(fd);
+                return NULL;
+        }
+        buffer[len] = '\0';
+        close(fd);
+
+        // clean data
+        int i;
+        for (i = 0; i < len; i++) {
+                if (buffer[i] == '\0')
+                        buffer[i] = ' ';
+                if (buffer[i] >= 0x80) // execv in progress!!!
+                        return NULL;
+        }
+
+        // return a malloc copy of the command line
+        char *rv = strdup((char *) buffer);
+        if (strlen(rv) == 0) {
+                free(rv);
+                return NULL;
+        }
+        return rv;
+}