pax_global_header00006660000000000000000000000064147161354750014527gustar00rootroot0000000000000052 comment=4e574f3ea9189e7677c7b14f557ce2212bd357f5 libpam-net-0.4/000077500000000000000000000000001471613547500134225ustar00rootroot00000000000000libpam-net-0.4/CMakeLists.txt000066400000000000000000000030401471613547500161570ustar00rootroot00000000000000cmake_minimum_required(VERSION 3.12) project("libpam-net" VERSION 0.3 DESCRIPTION "create/join network namespaces at login" HOMEPAGE_URL "https://github.com/rd235/libpam-net" LANGUAGES C) include(GNUInstallDirs) include(CheckIncludeFile) add_definitions(-D_GNU_SOURCE) include_directories(${CMAKE_CURRENT_SOURCE_DIR}) unset(NLINLINE_INCLUDE CACHE) check_include_file(nlinline.h NLINLINE_INCLUDE) if(NOT NLINLINE_INCLUDE) message(FATAL_ERROR "*** required nlinline.h include file not found.\nInstall nlinline: https://github.com/virtualsquare/nlinline") endif() if(LIBSECURITYDIR) set(CMAKE_INSTALL_PAMDIR ${LIBSECURITYDIR}) else() set(CMAKE_INSTALL_PAMDIR ${CMAKE_INSTALL_LIBDIR}/security) endif() add_library(pam_newnet SHARED pam_newnet.c pam_net_checkgroup.c) set_target_properties(pam_newnet PROPERTIES PREFIX "") add_library(pam_usernet SHARED pam_usernet.c pam_net_checkgroup.c) set_target_properties(pam_usernet PROPERTIES PREFIX "") target_compile_definitions(pam_usernet PUBLIC PAM_USERNET) add_library(pam_groupnet SHARED pam_groupnet.c pam_net_checkgroup.c) set_target_properties(pam_groupnet PROPERTIES PREFIX "") target_compile_definitions(pam_groupnet PUBLIC PAM_GROUPNET) install(TARGETS pam_newnet pam_usernet pam_groupnet DESTINATION ${CMAKE_INSTALL_PAMDIR}) file(GLOB MAN8_PAGES ${CMAKE_CURRENT_SOURCE_DIR}/*.8) install(FILES ${MAN8_PAGES} DESTINATION ${CMAKE_INSTALL_MANDIR}/man8) add_custom_target(uninstall "${CMAKE_COMMAND}" -DCADO_SPOOL_DIR=${CADO_SPOOL_DIR} -P "${PROJECT_SOURCE_DIR}/Uninstall.cmake" ) libpam-net-0.4/COPYING000066400000000000000000000431231471613547500144600ustar00rootroot00000000000000 GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. 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The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you". Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. 1. 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If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. 10. If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. NO WARRANTY 11. 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It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. Copyright (C) 19yy 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 St, Fifth Floor, Boston, MA 02110-1301, USA. Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) 19yy name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. , 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License. libpam-net-0.4/README.md000066400000000000000000000102631471613547500147030ustar00rootroot00000000000000## LIBPAM-NET: create/join network namespaces at login **libpam-net** implements three pam modules: - **pam_newnet.so**: users belonging to the *newnet* group get a new network namespace at login - **pam_usernet.so** users belonging to the *usernet* group get their own network name at login. If a network namespace having the same name as the username exists, pam runs the user's shell in that namespace. If such a namespace does does not exist, it is created during the login process. - **pam_groupnet.so** users belonging to any group starting with *groupnet-* join the network namespace named after the dash of the group. If the specified network namespace exists, pam runs the user shell in that namespace. If such a namespace does does not exist, it is created during the login process. ### INSTALL: #### Requirements **libpam-net** needs [**nlinline**](https://github.com/virtualsquare/nlinline). #### Get the source code: ``` git clone https://github.com/rd235/libpam-net.git ``` #### Update the source code: ``` git pull ``` #### Compile and install Run the following commands from the root of the source tree: ``` mkdir build cd build cmake .. -DLIBSECURITYDIR=/lib/x86_64-linux-gnu/security/ make sudo make install ``` #### Configuration Add the rules to the pam configuration files: e.g. */etc/pam.d/sshd* or */etc/pam.d/login* ``` session required pam_newnet.so session required pam_usernet.so session required pam_groupnet.so ``` Create the groups *newnet*, *usernet* and any (or none) *groupnet-** including all the users that must be subject to one or the other service: e.g. in /etc/group: ``` newnet:x:149:renzononet usernet:x:150:renzousernet groupnet-vpn:x:151:renzogroupnet ``` ### Use Cases #### Disallowing external network access for selected users Using **pam_newnet.so** users in the *newnet* group can log-in through a network connection (e.g. by ssh) but their processes cannot communicate with the network at all. The only interface they can see is an isolated loopback **lo** interface created at login time. ##### Segregated network namespaces for selected user Using **pam_usernet.so** the system administrator can create network namespaces for each user in the *usernet* group. Each namespace must be named after each username. Alternatively, using **pam_groupnet.so** the system administrator can create different network namespaces to be shared by multiple users. e.g. for forced VPN tunneling without affecting other users. Users will *land* in their assigned network namespace at login. e.g. the sysadmin can create a network namespace for user *renzousernet* as follows: ``` # ip netns add renzousernet # ip -netns renzousernet link set dev lo up # ip -netns renzousernet tuntap add name eth0 mode tap # ... ``` If the directory `/etc/netns//` exists files directly underneath it are mounted over files in `/etc`. This can be used for overriding the DNS nameserver settings in the user's netns. Taking *renzousernet* as an example again, this is what you'd do: ``` # cat > /etc/netns/renzousernet/resolv.conf <. * */ #include #include #include #include /* check if "user" belongs to "group" */ int checkgroup(const char *user, const char *group) { struct passwd *pw = getpwnam(user); struct group *gr = getgrnam(group); int ngroups=0; if (pw == NULL) return -1; if (gr == NULL) return 0; if (getgrouplist(user, pw->pw_gid, NULL, &ngroups) < 0) { gid_t gids[ngroups]; if (getgrouplist(user, pw->pw_gid, gids, &ngroups) == ngroups) { int i; for (i=0; igr_gid == gids[i]) return 1; } return 0; } } return -1; } char *get_groupnet_netns(const char *user, const char *group) { struct passwd *pw = getpwnam(user); int ngroups=0; if (pw == NULL || getgrouplist(user, pw->pw_gid, NULL, &ngroups) >= 0) { return NULL; } gid_t gids[ngroups]; if (getgrouplist(user, pw->pw_gid, gids, &ngroups) != ngroups) { return NULL; } int grouplen = strlen(group); int i; struct group *gr; for (i=0; igr_name, group, grouplen) == 0 && strlen(gr->gr_name) > grouplen + 1 && gr->gr_name[grouplen] == '-') { return strdup(gr->gr_name + grouplen + 1); } } return NULL; } libpam-net-0.4/pam_net_checkgroup.h000066400000000000000000000007551471613547500174370ustar00rootroot00000000000000#ifndef PAM_NET_COMMON_H #define PAM_NET_COMMON_H /* check if "user" belongs to "group" */ /* 0=NO 1=YES -1=error */ int checkgroup(const char *user, const char *group); /* get the name specified after a dash char '-' of "group" on a user. * if the user is part of multiple groups starting with "group", returns data from first matching group. */ /* NULL = not found/error. pointer must be freed. */ char *get_groupnet_netns(const char *user, const char *group); #endif //PAM_NET_COMMON_H libpam-net-0.4/pam_newnet.8000066400000000000000000000032741471613547500156560ustar00rootroot00000000000000.TH PAM_NEWNET 8 "October 5, 2019" "VirtualSquare Labs" .SH "NAME" pam_newnet \- create a new network namespace at login .SH "SYNOPSIS" \fBpam_newnet\&.so\fR .SH DESCRIPTION The pam_newnet PAM module creates a new network namespace at login for users in the \fInewnet\fR group. Users in the \fInewnet\fR group can log-in through a network connection (e.g. by ssh) but their processes cannot communicate. The only interface they can see is the localhost of the namespace created at login time. When pam_newnet is used together with a specific \fBcado(1)\fR configuration users can configure their own networking services. (see https://github.com/rd235/cado) The nsutils tools, and more specfically \fBnetnsjoin(1)\fR, allow users to assign placeholders to keep namespaces alive, assign meaningful tags for an easier management, and later join any of their own namespaces (see https://github.com/rd235/nsutils) .SH "OPTIONS" .PP \fBgroup=\fR\fB\fIgroupname\fR\fR .RS 4 the module operates on users in the group \fIgroupname\fR instead of \fInewnet\fR. .RE .PP \fBlodown\fR .RS 4 leave the localhost \fIlo\fR interface in the state DOWN. .RE .SH "RETURN VALUES" .PP PAM_IGNORE .RS 4 User does not belong to the \fInewnet\fR group\&. .RE .PP PAM_ABORT .RS 4 Error in retrieving the user id or in the namespace creation\&. .RE .PP PAM_SUCCESS .RS 4 Success\&. .RE .SH "EXAMPLES" .PP Add the following lines to /etc/pam\&.d/sshd or /etc/pam\&.d/login .sp .RS 8 session required pam_newnet.so .sp session required pam_newnet.so group=lonet lodown .RE .sp .SH "SEE ALSO" .PP \fBpam.conf\fR(5), \fBpam.d\fR(5), \fBpam\fR(7) .SH "AUTHOR" .PP pam_newnet was written by Renzo Davoli and Eduard Caizer, University of Bologna libpam-net-0.4/pam_newnet.c000066400000000000000000000056051471613547500157310ustar00rootroot00000000000000/* * pam_newnet. * Copyright (C) 2016 Renzo Davoli, Eduard Caizer University of Bologna * * pam_newnet module * create a new network namespace at each login * (for users belonging to the "newnet" group) * * Cado 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 . * */ #include #include #include #include #include #include #include #include #include #define DEFAULT_GROUP "newnet" /** * module args: * lodown, rootshared, group=.... */ struct pam_net_args { const char *group; int flags; }; #define LODOWN 0x1 /** * parse_argv: parse module arguments */ static void parse_argv(struct pam_net_args *args, int argc, const char **argv) { for(; argc-- > 0; argv++) { if (strcmp(*argv, "lodown") == 0) args->flags |= LODOWN; else if (strncmp(*argv, "group=", 6) == 0) args->group = (*argv) + 6; else syslog (LOG_ERR, "Unknown option: %s", *argv); } } /** * init_log: log initialization with the given name */ void init_log(const char * log_name) { setlogmask (LOG_UPTO (LOG_NOTICE)); openlog (log_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1); } /** * end_log: closes the log previously initialized */ void end_log() { closelog (); } /* * PAM entry point for session creation */ int pam_sm_open_session(pam_handle_t *pamh, int flags, int argc, const char **argv) { const char *user; int rv; int isnewnet; struct pam_net_args pam_args = { .group = DEFAULT_GROUP, .flags = 0}; init_log ("pam_newnet"); parse_argv(&pam_args, argc, argv); if ((rv=pam_get_user(pamh, &user, NULL) != PAM_SUCCESS)) { syslog (LOG_ERR, "get user: %s", strerror(errno)); goto close_log_and_exit; } isnewnet = checkgroup(user, pam_args.group); if (isnewnet > 0) { if (unshare(CLONE_NEWNET) < 0) { syslog (LOG_ERR, "Failed to create a new netns: %s", strerror(errno)); goto close_log_and_abort; } if ((pam_args.flags & LODOWN) == 0) nlinline_linksetupdown(1, 1); // bring lo up } else rv=PAM_IGNORE; close_log_and_exit: end_log(); return rv; close_log_and_abort: rv = PAM_ABORT; end_log(); return rv; } /* * PAM entry point for session cleanup */ int pam_sm_close_session(pam_handle_t *pamh, int flags, int argc, const char **argv) { return(PAM_IGNORE); } libpam-net-0.4/pam_usernet.8000066400000000000000000000034271471613547500160430ustar00rootroot00000000000000.TH PAM_USERNET 8 "August 17, 2016" "VirtualSquare Labs" .SH "NAME" pam_usernet \- join the user own network namespace at login .SH "SYNOPSIS" \fBpam_usernet\&.so\fR .SH DESCRIPTION The pam_usernet PAM module allow each user in \fIusernet\fR group to have their own network namespace. If a network namespace having the same name as the username exists, pam runs the user shell in that namespace. If such a namespace does does not exist, it is created during the login process. The system administrator can create a network namespace for each user in \fIusernet\fR group. Each namespace must be named after each username. Users will get their own network namespace at login. When pam_usernet is used together with a specific \fBcado(1)\fR configuration users can configure their own networking services. (see https://github.com/rd235/cado) .SH "OPTIONS" .PP \fBgroup=\fR\fB\fIgroupname\fR\fR .RS 4 the module operates on users in the group \fIgroupname\fR instead of \fIusernet\fR. .RE .PP \fBlodown\fR .RS 4 leave the localhost \fIlo\fR interface in the state DOWN. .RE .PP \fBrootshared\fR .RS 4 Leave the root filesystem \fI/\fR as shared so mounts can propagate out to the parent namespace. Warning: this feature can create security vulnerabilities if not properly used. .RE .SH "RETURN VALUES" .PP PAM_IGNORE .RS 4 User does not belong to the \fIusernet\fR group\&. .RE .PP PAM_ABORT .RS 4 Error in retrieving the user id or in the namespace creation/joining\&. .RE .PP PAM_SUCCESS .RS 4 Success\&. .RE .SH "EXAMPLES" .PP Add the following line to /etc/pam\&.d/sshd or /etc/pam\&.d/login .sp .RS 8 session required pam_usernet.so .RE .sp .SH "SEE ALSO" .PP \fBpam.conf\fR(5), \fBpam.d\fR(5), \fBpam\fR(7) .SH "AUTHOR" .PP pam_usernet was written by Renzo Davoli and Eduard Caizer, University of Bologna libpam-net-0.4/pam_usernet.c000066400000000000000000000237101471613547500161130ustar00rootroot00000000000000/* * pam_usernet / pam_groupnet (shared source) * Copyright (C) 2017-2024 Renzo Davoli University of Bologna * Copyright (C) 2018-2019 Daniel Gröber * Copyright (C) 2016 Renzo Davoli, Eduard Caizer University of Bologna * Copyright (C) 2011-2017 The iproute2 Authors * * pam_usernet module * provide each user with their own network * (for users belonging to the "usernet" group) * * pam_groupnet module * join users to a specific new or existing network, specified after the dash on the group name. * (for users belonging to the "groupnet-*" group) * * Cado 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 . * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef PAM_USERNET #define DEFAULT_GROUP "usernet" #elif PAM_GROUPNET #define DEFAULT_GROUP "groupnet" #else #error either -DPAM_USERNET or -DPAM_GROUPNET must be defined #endif #define NETNS_RUN_DIR "/var/run/netns/" #define NETNS_ETC_DIR "/etc/netns" /** * module args: * lodown, rootshared, group=.... */ struct pam_net_args { const char *group; int flags; }; #define LODOWN 0x1 #define ROOTSHARED 0x2 /** * parse_argv: parse module arguments */ static void parse_argv(struct pam_net_args *args, int argc, const char **argv) { for(; argc-- > 0; argv++) { if (strcmp(*argv, "lodown") == 0) args->flags |= LODOWN; else if (strcmp(*argv, "rootshared") == 0) args->flags |= ROOTSHARED; else if (strncmp(*argv, "group=", 6) == 0) args->group = (*argv) + 6; else syslog (LOG_ERR, "Unknown option: %s", *argv); } } /** * init_log: log initialization with the given name */ void init_log(const char * log_name) { setlogmask (LOG_UPTO (LOG_NOTICE)); openlog (log_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1); } /** * end_log: closes the log previously initialized */ void end_log() { closelog (); } /** * bind_etc: Mount config files from /etc/netns// into current namespace. */ int bind_etc(const char *name, int flags) { int rv = 0; char etc_netns_path[sizeof(NETNS_ETC_DIR) + NAME_MAX]; char netns_name[PATH_MAX]; char etc_name[PATH_MAX]; struct dirent *entry; DIR *dir; if (flags & ROOTSHARED) { /* ROOTSHARED */ /* Make /etc a mount point, so we can apply a propagation policy to it * below */ rv = mount("/etc", "/etc", "none", MS_BIND, NULL); if (rv == -1) { syslog (LOG_ERR, "mount --bind %s %s: %s", etc_netns_path, etc_netns_path, strerror(errno)); return -1; } /* Don't let bind mounts from /etc/netns// -> /etc/ * propagate back to the parent namespace */ if (mount("", "/etc", "none", MS_PRIVATE, NULL)) { syslog (LOG_ERR, "\"mount --make-private /%s\" failed: %s\n", etc_netns_path, strerror(errno)); return -1; } } snprintf(etc_netns_path, sizeof(etc_netns_path), "%s/%s", NETNS_ETC_DIR, name); dir = opendir(etc_netns_path); if (!dir) return errno == ENOENT ? 0 : -1; while ((entry = readdir(dir)) != NULL) { if (strcmp(entry->d_name, ".") == 0) continue; if (strcmp(entry->d_name, "..") == 0) continue; snprintf(netns_name, sizeof(netns_name), "%s/%s", etc_netns_path, entry->d_name); snprintf(etc_name, sizeof(etc_name), "/etc/%s", entry->d_name); if (mount(netns_name, etc_name, "none", MS_BIND, NULL) < 0) { syslog (LOG_ERR, "Bind %s -> %s failed: %s", netns_name, etc_name, strerror(errno)); } } closedir(dir); return 0; } /** * remount_sys: Mount a version of /sys that describes the new network namespace */ int remount_sys(const char *name, int flags) { unsigned long mountflags = MS_NOSUID | MS_NOEXEC | MS_NODEV; if ((flags & ROOTSHARED) == 0) { /* DEFAULT behavior: NOT ROOTSHARED */ /* Don't let any mounts propagate back to the parent */ if (mount("", "/", "none", MS_SLAVE | MS_REC, NULL)) { fprintf(stderr, "\"mount --make-rslave /\" failed: %s\n", strerror(errno)); return -1; } } else { /* ROOTSHARED */ /* Make /sys private so the remounting below doesn't * propagate to the parent namespace, since we're leaving * the root directory shared */ if (mount("", "/sys", "none", MS_PRIVATE | MS_REC, NULL)) { syslog (LOG_ERR, "\"mount --make-rprivate /sys\" failed: %s\n", strerror(errno)); return -1; } } /* Mount a version of /sys that describes the network namespace */ if (umount2("/sys", MNT_DETACH) < 0) { struct statvfs fsstat; /* If this fails, perhaps there wasn't a sysfs instance * mounted. Good. */ if (statvfs("/sys", &fsstat) == 0) { /* We couldn't umount the sysfs, we'll attempt to * overlay it. A read-only instance can't be shadowed * with a read-write one. */ if (fsstat.f_flag & ST_RDONLY) mountflags |= MS_RDONLY; } } if (mount(name, "/sys", "sysfs", mountflags, NULL) < 0) { syslog (LOG_ERR, "mount of /sys failed: %s", strerror(errno)); return -1; } if (mount("cgroup2", "/sys/fs/cgroup", "cgroup2", mountflags, NULL) < 0) { syslog (LOG_ERR, "mount of /sys/fs/cgroup failed: %s", strerror(errno)); return -1; } return 0; } /** * create_netns_rundir: Create /var/run/netns mount if it doesn't exist yet. */ int create_netns_rundir(void) { int rv = 0; rv = mkdir(NETNS_RUN_DIR, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH); if (rv == -1 && errno != EEXIST) { syslog (LOG_ERR, "cannot create netns dir %s: %s", NETNS_RUN_DIR, strerror(errno)); return -1; } rv = mount("", NETNS_RUN_DIR, "none", MS_SHARED | MS_REC, NULL); if (rv == 0) { return 0; } if (errno != EINVAL) { syslog (LOG_ERR, "mount --make-shared %s: %s", NETNS_RUN_DIR, strerror(errno)); return -1; } rv = mount(NETNS_RUN_DIR, NETNS_RUN_DIR, "none", MS_BIND, NULL); if (rv == -1) { syslog (LOG_ERR, "mount --bind %s: %s", NETNS_RUN_DIR, strerror(errno)); return -1; } rv = mount("", NETNS_RUN_DIR, "none", MS_SHARED | MS_REC, NULL); if (rv == -1) { syslog (LOG_ERR, "mount --make-shared after bind %s: %s", NETNS_RUN_DIR, strerror(errno)); return -1; } return 0; } /** * unshare_netns: Create new netns, including mounting the handle to ns_path. */ int unshare_netns(char *ns_path, int flags) { int rv; int nsfd; nsfd = open(ns_path, O_RDONLY|O_CREAT|O_EXCL, 0); if (nsfd < 0) { syslog (LOG_ERR, "cannot create netns %s: %s", ns_path, strerror(errno)); return -1; } close(nsfd); rv = unshare(CLONE_NEWNET); if (rv < 0) { syslog (LOG_ERR, "Failed to create a new netns %s: %s", ns_path, strerror(errno)); return -1; } rv = mount("/proc/self/ns/net", ns_path, "none", MS_BIND, NULL); if (rv == -1) { syslog (LOG_ERR, "mount /proc/self/ns/net -> %s failed: %s", ns_path, strerror(errno)); return -1; } if ((flags & LODOWN) == 0) nlinline_linksetupdown(1, 1); // bring lo up return nsfd; } /** * enter_netns: Ensure we are in the netns referred to by ns_path, either by * creating it or entering it if it already exists. */ int enter_netns(char *ns_path, int flags) { int nsfd; nsfd = open(ns_path, O_RDONLY); if (nsfd < 0) { if (errno == ENOENT) { unshare_netns(ns_path, flags); } else { syslog (LOG_ERR, "netns open failed %s", ns_path); return -1; } } else { if (setns(nsfd, CLONE_NEWNET) != 0) { syslog (LOG_ERR, "cannot join netns %s: %s", ns_path, strerror(errno)); close(nsfd); return -1; } close(nsfd); } return 0; } /* * PAM entry point for session creation */ int pam_sm_open_session(pam_handle_t *pamh, int flags, int argc, const char **argv) { const char *user; int rv; char *target_netns = NULL; char ns_path[PATH_MAX]; struct pam_net_args pam_args = { .group = DEFAULT_GROUP, .flags = 0}; #ifdef PAM_USERNET init_log ("pam_usernet"); #elif PAM_GROUPNET init_log ("pam_groupnet"); #endif parse_argv(&pam_args, argc, argv); if ((rv=pam_get_user(pamh, &user, NULL) != PAM_SUCCESS)) { syslog (LOG_ERR, "get user: %s", strerror(errno)); end_log(); return PAM_SUCCESS; } #ifdef PAM_USERNET if (checkgroup(user, pam_args.group) > 0) target_netns = (char *) user; #elif PAM_GROUPNET target_netns = get_groupnet_netns(user, pam_args.group); #endif if(target_netns == NULL) { end_log(); return PAM_IGNORE; } if (create_netns_rundir() == -1) goto close_log_and_abort; snprintf(ns_path, sizeof(ns_path), "%s/%s", NETNS_RUN_DIR, target_netns); rv = enter_netns(ns_path, pam_args.flags); if(rv == -1) goto close_log_and_abort; if (unshare(CLONE_NEWNS) < 0) { syslog (LOG_ERR, "unshare(mount) failed: %s", strerror(errno)); goto close_log_and_abort; } if(remount_sys(target_netns, pam_args.flags) == -1) { syslog (LOG_ERR, "remounting /sys failed"); goto close_log_and_abort; } /* Setup bind mounts for config files in /etc */ if(bind_etc(target_netns, pam_args.flags) == -1) { syslog (LOG_ERR, "mounting /etc/netns/%s config files failed", target_netns); goto close_log_and_abort; } #ifdef PAM_GROUPNET free(target_netns); #endif end_log(); return PAM_SUCCESS; close_log_and_abort: #ifdef PAM_GROUPNET free(target_netns); #endif end_log(); return PAM_ABORT; } /* * PAM entry point for session cleanup */ int pam_sm_close_session(pam_handle_t *pamh, int flags, int argc, const char **argv) { return(PAM_IGNORE); }