| Index: src/dnsmasq.c |
| =================================================================== |
| --- src/dnsmasq.c (revision 696) |
| +++ src/dnsmasq.c (revision 821) |
| @@ -59,7 +59,6 @@ |
| static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp); |
| static void check_dns_listeners(fd_set *set, time_t now); |
| static void sig_handler(int sig); |
| -static void async_event(int pipe, time_t now); |
| static void fatal_event(struct event_desc *ev); |
| static void poll_resolv(void); |
| |
| @@ -275,7 +274,7 @@ |
| piperead = pipefd[0]; |
| pipewrite = pipefd[1]; |
| /* prime the pipe to load stuff first time. */ |
| - send_event(pipewrite, EVENT_RELOAD, 0); |
| + send_event(pipewrite, EVENT_RELOAD, 0, 0); |
| |
| err_pipe[1] = -1; |
| |
| @@ -340,7 +339,7 @@ |
| } |
| else if (getuid() == 0) |
| { |
| - send_event(err_pipe[1], EVENT_PIDFILE, errno); |
| + send_event(err_pipe[1], EVENT_PIDFILE, errno, 0); |
| _exit(0); |
| } |
| } |
| @@ -372,7 +371,7 @@ |
| (setgroups(0, &dummy) == -1 || |
| setgid(gp->gr_gid) == -1)) |
| { |
| - send_event(err_pipe[1], EVENT_GROUP_ERR, errno); |
| + send_event(err_pipe[1], EVENT_GROUP_ERR, errno, 0); |
| _exit(0); |
| } |
| |
| @@ -415,14 +414,14 @@ |
| |
| if (bad_capabilities != 0) |
| { |
| - send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities); |
| + send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, 0); |
| _exit(0); |
| } |
| |
| /* finally drop root */ |
| if (setuid(ent_pw->pw_uid) == -1) |
| { |
| - send_event(err_pipe[1], EVENT_USER_ERR, errno); |
| + send_event(err_pipe[1], EVENT_USER_ERR, errno, 0); |
| _exit(0); |
| } |
| |
| @@ -434,7 +433,7 @@ |
| /* lose the setuid and setgid capabilities */ |
| if (capset(hdr, data) == -1) |
| { |
| - send_event(err_pipe[1], EVENT_CAP_ERR, errno); |
| + send_event(err_pipe[1], EVENT_CAP_ERR, errno, 0); |
| _exit(0); |
| } |
| #endif |
| @@ -647,7 +646,7 @@ |
| } |
| |
| if (FD_ISSET(piperead, &rset)) |
| - async_event(piperead, now); |
| + async_event(piperead, now, NULL, 0); |
| |
| #ifdef HAVE_LINUX_NETWORK |
| if (FD_ISSET(daemon->netlinkfd, &rset)) |
| @@ -674,7 +673,7 @@ |
| #endif |
| |
| if (daemon->dhcp && FD_ISSET(daemon->dhcpfd, &rset)) |
| - dhcp_packet(now); |
| + dhcp_packet(piperead, now); |
| |
| #ifndef NO_FORK |
| if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
| @@ -719,17 +718,18 @@ |
| else |
| return; |
| |
| - send_event(pipewrite, event, 0); |
| + send_event(pipewrite, event, 0, 0); |
| errno = errsave; |
| } |
| } |
| |
| -void send_event(int fd, int event, int data) |
| +void send_event(int fd, int event, int data, int priv) |
| { |
| struct event_desc ev; |
| |
| ev.event = event; |
| ev.data = data; |
| + ev.priv = priv; |
| |
| /* error pipe, debug mode. */ |
| if (fd == -1) |
| @@ -771,14 +771,17 @@ |
| die(_("cannot open %s: %s"), daemon->log_file ? daemon->log_file : "log", EC_FILE); |
| } |
| } |
| - |
| -static void async_event(int pipe, time_t now) |
| + |
| +/* returns the private data of the event |
| + */ |
| +int async_event(int pipe, time_t now, struct event_desc* event, unsigned int secs) |
| { |
| pid_t p; |
| struct event_desc ev; |
| int i; |
| |
| - if (read_write(pipe, (unsigned char *)&ev, sizeof(ev), 1)) |
| + if (read_timeout(pipe, (unsigned char *)&ev, sizeof(ev), now, secs) > 0) |
| + { |
| switch (ev.event) |
| { |
| case EVENT_RELOAD: |
| @@ -872,6 +875,14 @@ |
| flush_log(); |
| exit(EC_GOOD); |
| } |
| + } |
| + else |
| + return -1; /* timeout */ |
| + |
| + if (event) |
| + memcpy( event, &ev, sizeof(ev)); |
| + |
| + return 0; |
| } |
| |
| static void poll_resolv() |
| Index: src/config.h |
| =================================================================== |
| --- src/config.h (revision 696) |
| +++ src/config.h (revision 821) |
| @@ -51,6 +51,8 @@ |
| #define TFTP_MAX_CONNECTIONS 50 /* max simultaneous connections */ |
| #define LOG_MAX 5 /* log-queue length */ |
| #define RANDFILE "/dev/urandom" |
| +#define SCRIPT_TIMEOUT 6 |
| +#define LEASE_CHECK_TIMEOUT 10 |
| |
| /* DBUS interface specifics */ |
| #define DNSMASQ_SERVICE "uk.org.thekelleys.dnsmasq" |
| Index: src/dnsmasq.h |
| =================================================================== |
| --- src/dnsmasq.h (revision 696) |
| +++ src/dnsmasq.h (revision 821) |
| @@ -116,6 +116,7 @@ |
| /* Async event queue */ |
| struct event_desc { |
| int event, data; |
| + unsigned int priv; |
| }; |
| |
| #define EVENT_RELOAD 1 |
| @@ -390,6 +391,7 @@ |
| #define ACTION_OLD_HOSTNAME 2 |
| #define ACTION_OLD 3 |
| #define ACTION_ADD 4 |
| +#define ACTION_ACCESS 5 |
| |
| #define DHCP_CHADDR_MAX 16 |
| |
| @@ -709,6 +711,7 @@ |
| char *print_mac(char *buff, unsigned char *mac, int len); |
| void bump_maxfd(int fd, int *max); |
| int read_write(int fd, unsigned char *packet, int size, int rw); |
| +int read_timeout(int fd, unsigned char *packet, int size, time_t now, int secs); |
| |
| /* log.c */ |
| void die(char *message, char *arg1, int exit_code); |
| @@ -748,7 +751,7 @@ |
| |
| /* dhcp.c */ |
| void dhcp_init(void); |
| -void dhcp_packet(time_t now); |
| +void dhcp_packet(int piperead, time_t now); |
| |
| struct dhcp_context *address_available(struct dhcp_context *context, |
| struct in_addr addr, |
| @@ -792,14 +795,16 @@ |
| void rerun_scripts(void); |
| |
| /* rfc2131.c */ |
| -size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index, |
| +size_t dhcp_reply(int pipefd, struct dhcp_context *context, char *iface_name, int int_index, |
| size_t sz, time_t now, int unicast_dest, int *is_inform); |
| |
| /* dnsmasq.c */ |
| int make_icmp_sock(void); |
| int icmp_ping(struct in_addr addr); |
| -void send_event(int fd, int event, int data); |
| +void send_event(int fd, int event, int data, int priv); |
| void clear_cache_and_reload(time_t now); |
| +int wait_for_child(int pipe); |
| +int async_event(int pipe, time_t now, struct event_desc*, unsigned int timeout); |
| |
| /* isc.c */ |
| #ifdef HAVE_ISC_READER |
| @@ -832,9 +837,9 @@ |
| /* helper.c */ |
| #ifndef NO_FORK |
| int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd); |
| -void helper_write(void); |
| +int helper_write(void); |
| void queue_script(int action, struct dhcp_lease *lease, |
| - char *hostname, time_t now); |
| + char *hostname, time_t now, unsigned int uid); |
| int helper_buf_empty(void); |
| #endif |
| |
| Index: src/util.c |
| =================================================================== |
| --- src/util.c (revision 696) |
| +++ src/util.c (revision 821) |
| @@ -444,3 +444,38 @@ |
| return 1; |
| } |
| |
| +int read_timeout(int fd, unsigned char *packet, int size, time_t now, int secs) |
| +{ |
| + ssize_t n, done; |
| + time_t expire; |
| + |
| + expire = now + secs; |
| + |
| + for (done = 0; done < size; done += n) |
| + { |
| + retry: |
| + if (secs > 0) alarm(secs); |
| + n = read(fd, &packet[done], (size_t)(size - done)); |
| + |
| + if (n == 0) |
| + return 0; |
| + else if (n == -1) |
| + { |
| + if (errno == EINTR) { |
| + my_syslog(LOG_INFO, _("read timed out (errno %d)"), errno); |
| + return 0; |
| + } |
| + |
| + if (retry_send() || errno == ENOMEM || errno == ENOBUFS || errno == EAGAIN) |
| + { |
| + if (secs == 0 || (secs > 0 && dnsmasq_time() < expire)) |
| + goto retry; |
| + } |
| + |
| + my_syslog(LOG_INFO, _("error in read (timeout %d, errno %d)"), secs, errno); |
| + return 0; |
| + } |
| + } |
| + return 1; |
| +} |
| + |
| Index: src/dhcp.c |
| =================================================================== |
| --- src/dhcp.c (revision 696) |
| +++ src/dhcp.c (revision 821) |
| @@ -103,7 +103,7 @@ |
| daemon->dhcp_packet.iov_base = safe_malloc(daemon->dhcp_packet.iov_len); |
| } |
| |
| -void dhcp_packet(time_t now) |
| +void dhcp_packet(int piperead, time_t now) |
| { |
| struct dhcp_packet *mess; |
| struct dhcp_context *context; |
| @@ -239,7 +239,8 @@ |
| if (!iface_enumerate(&parm, complete_context, NULL)) |
| return; |
| lease_prune(NULL, now); /* lose any expired leases */ |
| - iov.iov_len = dhcp_reply(parm.current, ifr.ifr_name, iface_index, (size_t)sz, |
| + |
| + iov.iov_len = dhcp_reply(piperead, parm.current, ifr.ifr_name, iface_index, (size_t)sz, |
| now, unicast_dest, &is_inform); |
| lease_update_file(now); |
| lease_update_dns(); |
| Index: src/helper.c |
| =================================================================== |
| --- src/helper.c (revision 696) |
| +++ src/helper.c (revision 821) |
| @@ -45,6 +45,7 @@ |
| #endif |
| unsigned char hwaddr[DHCP_CHADDR_MAX]; |
| char interface[IF_NAMESIZE]; |
| + unsigned int uid; |
| }; |
| |
| static struct script_data *buf = NULL; |
| @@ -60,7 +61,7 @@ |
| then fork our process. */ |
| if (pipe(pipefd) == -1 || !fix_fd(pipefd[1]) || (pid = fork()) == -1) |
| { |
| - send_event(err_fd, EVENT_PIPE_ERR, errno); |
| + send_event(err_fd, EVENT_PIPE_ERR, errno, 0); |
| _exit(0); |
| } |
| |
| @@ -87,13 +88,13 @@ |
| { |
| if (daemon->options & OPT_NO_FORK) |
| /* send error to daemon process if no-fork */ |
| - send_event(event_fd, EVENT_HUSER_ERR, errno); |
| + send_event(event_fd, EVENT_HUSER_ERR, errno, 0); |
| else |
| { |
| /* kill daemon */ |
| - send_event(event_fd, EVENT_DIE, 0); |
| + send_event(event_fd, EVENT_DIE, 0, 0); |
| /* return error */ |
| - send_event(err_fd, EVENT_HUSER_ERR, errno);; |
| + send_event(err_fd, EVENT_HUSER_ERR, errno, 0); |
| } |
| _exit(0); |
| } |
| @@ -122,6 +123,8 @@ |
| action_str = "del"; |
| else if (data.action == ACTION_ADD) |
| action_str = "add"; |
| + else if (data.action == ACTION_ACCESS) |
| + action_str = "access"; |
| else if (data.action == ACTION_OLD || data.action == ACTION_OLD_HOSTNAME) |
| action_str = "old"; |
| else |
| @@ -178,9 +181,11 @@ |
| { |
| /* On error send event back to main process for logging */ |
| if (WIFSIGNALED(status)) |
| - send_event(event_fd, EVENT_KILLED, WTERMSIG(status)); |
| - else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) |
| - send_event(event_fd, EVENT_EXITED, WEXITSTATUS(status)); |
| + send_event(event_fd, EVENT_KILLED, WTERMSIG(status), data.uid); |
| + else if (WIFEXITED(status)) |
| + send_event(event_fd, EVENT_EXITED, WEXITSTATUS(status), data.uid); |
| + else |
| + send_event(event_fd, EVENT_EXITED, -1, data.uid); |
| break; |
| } |
| |
| @@ -263,7 +268,7 @@ |
| err = errno; |
| } |
| /* failed, send event so the main process logs the problem */ |
| - send_event(event_fd, EVENT_EXEC_ERR, err); |
| + send_event(event_fd, EVENT_EXEC_ERR, err, data.uid); |
| _exit(0); |
| } |
| } |
| @@ -295,7 +300,7 @@ |
| } |
| |
| /* pack up lease data into a buffer */ |
| -void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t now) |
| +void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t now, unsigned int uid) |
| { |
| unsigned char *p; |
| size_t size; |
| @@ -332,6 +337,7 @@ |
| buf_size = size; |
| } |
| |
| + buf->uid = uid; |
| buf->action = action; |
| buf->hwaddr_len = lease->hwaddr_len; |
| buf->hwaddr_type = lease->hwaddr_type; |
| @@ -393,12 +399,15 @@ |
| return bytes_in_buf == 0; |
| } |
| |
| -void helper_write(void) |
| +/* returns -1 if write failed for a reason, 1 if no data exist |
| + * and 0 if everything was ok. |
| + */ |
| +int helper_write(void) |
| { |
| ssize_t rc; |
| |
| if (bytes_in_buf == 0) |
| - return; |
| + return 1; |
| |
| if ((rc = write(daemon->helperfd, buf, bytes_in_buf)) != -1) |
| { |
| @@ -409,9 +418,11 @@ |
| else |
| { |
| if (errno == EAGAIN || errno == EINTR) |
| - return; |
| + return -1; |
| bytes_in_buf = 0; |
| } |
| + |
| + return 0; |
| } |
| |
| #endif |
| Index: src/rfc2131.c |
| =================================================================== |
| --- src/rfc2131.c (revision 696) |
| +++ src/rfc2131.c (revision 821) |
| @@ -100,8 +100,49 @@ |
| int clid_len, unsigned char *clid, int *len_out); |
| static void match_vendor_opts(unsigned char *opt, struct dhcp_opt *dopt); |
| |
| +static int check_access_script( int piperead, struct dhcp_lease *lease, struct dhcp_packet *mess, time_t now) |
| +{ |
| +#ifndef NO_FORK |
| +unsigned int uid; |
| +struct event_desc ev; |
| +int ret; |
| +struct dhcp_lease _lease; |
| + |
| + if (daemon->lease_change_command == NULL) return 0; /* ok */ |
| + |
| + if (!lease) { /* if host has not been seen before lease is NULL */ |
| + memset(&_lease, 0, sizeof(_lease)); |
| + lease = &_lease; |
| + lease_set_hwaddr(lease, mess->chaddr, NULL, mess->hlen, mess->htype, 0); |
| + } |
| + |
| + uid = rand16(); |
| + queue_script(ACTION_ACCESS, lease, NULL, now, uid); |
| + |
| + /* send all data to helper process */ |
| + do |
| + { |
| + helper_write(); |
| + } while (helper_buf_empty() == 0); |
| + |
| + /* wait for our event */ |
| + ret = 0; |
| + do |
| + { |
| + ret = async_event( piperead, now, &ev, SCRIPT_TIMEOUT); |
| + } |
| + while(ev.priv != uid && ret >= 0); |
| + |
| + if (ret < 0 || ev.data != 0) /* timeout or error */ |
| + { |
| + return -1; |
| + } |
| + |
| +#endif |
| + return 0; /* ok */ |
| +} |
| |
| -size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index, |
| +size_t dhcp_reply(int piperead, struct dhcp_context *context, char *iface_name, int int_index, |
| size_t sz, time_t now, int unicast_dest, int *is_inform) |
| { |
| unsigned char *opt, *clid = NULL; |
| @@ -252,7 +293,7 @@ |
| mac->netid.next = netid; |
| netid = &mac->netid; |
| } |
| - |
| + |
| /* Determine network for this packet. Our caller will have already linked all the |
| contexts which match the addresses of the receiving interface but if the |
| machine has an address already, or came via a relay, or we have a subnet selector, |
| @@ -329,7 +370,7 @@ |
| my_syslog(LOG_INFO, _("Available DHCP range: %s -- %s"), daemon->namebuff, inet_ntoa(context_tmp->end)); |
| } |
| } |
| - |
| + |
| mess->op = BOOTREPLY; |
| |
| config = find_config(daemon->dhcp_conf, context, clid, clid_len, |
| @@ -418,7 +459,7 @@ |
| else |
| mess->yiaddr = lease->addr; |
| } |
| - |
| + |
| if (!message && |
| !lease && |
| (!(lease = lease_allocate(mess->yiaddr)))) |
| @@ -641,7 +682,14 @@ |
| memcpy(req_options, option_ptr(opt, 0), option_len(opt)); |
| req_options[option_len(opt)] = OPTION_END; |
| } |
| - |
| + |
| + if (mess_type == DHCPREQUEST || mess_type == DHCPDISCOVER) |
| + if (check_access_script(piperead, lease, mess, now) < 0) |
| + { |
| + my_syslog(LOG_INFO, _("Ignoring client due to access script")); |
| + return 0; |
| + } |
| + |
| switch (mess_type) |
| { |
| case DHCPDECLINE: |
| Index: src/log.c |
| =================================================================== |
| --- src/log.c (revision 696) |
| +++ src/log.c (revision 821) |
| @@ -73,7 +73,7 @@ |
| |
| if (!log_reopen(daemon->log_file)) |
| { |
| - send_event(errfd, EVENT_LOG_ERR, errno); |
| + send_event(errfd, EVENT_LOG_ERR, errno, 0); |
| _exit(0); |
| } |
| |
| Index: src/lease.c |
| =================================================================== |
| --- src/lease.c (revision 696) |
| +++ src/lease.c (revision 821) |
| @@ -511,7 +511,7 @@ |
| if (lease->old_hostname) |
| { |
| #ifndef NO_FORK |
| - queue_script(ACTION_OLD_HOSTNAME, lease, lease->old_hostname, now); |
| + queue_script(ACTION_OLD_HOSTNAME, lease, lease->old_hostname, now, 0); |
| #endif |
| free(lease->old_hostname); |
| lease->old_hostname = NULL; |
| @@ -520,7 +520,7 @@ |
| else |
| { |
| #ifndef NO_FORK |
| - queue_script(ACTION_DEL, lease, lease->hostname, now); |
| + queue_script(ACTION_DEL, lease, lease->hostname, now, 0); |
| #endif |
| old_leases = lease->next; |
| |
| @@ -540,7 +540,7 @@ |
| if (lease->old_hostname) |
| { |
| #ifndef NO_FORK |
| - queue_script(ACTION_OLD_HOSTNAME, lease, lease->old_hostname, now); |
| + queue_script(ACTION_OLD_HOSTNAME, lease, lease->old_hostname, now, 0); |
| #endif |
| free(lease->old_hostname); |
| lease->old_hostname = NULL; |
| @@ -552,7 +552,7 @@ |
| (lease->aux_changed && (daemon->options & OPT_LEASE_RO))) |
| { |
| #ifndef NO_FORK |
| - queue_script(lease->new ? ACTION_ADD : ACTION_OLD, lease, lease->hostname, now); |
| + queue_script(lease->new ? ACTION_ADD : ACTION_OLD, lease, lease->hostname, now, 0); |
| #endif |
| lease->new = lease->changed = lease->aux_changed = 0; |
| |
| Index: man/dnsmasq.8 |
| =================================================================== |
| --- man/dnsmasq.8 (revision 696) |
| +++ man/dnsmasq.8 (revision 821) |
| @@ -724,12 +724,15 @@ |
| .B \-6 --dhcp-script=<path> |
| Whenever a new DHCP lease is created, or an old one destroyed, the |
| binary specified by this option is run. The arguments to the process |
| -are "add", "old" or "del", the MAC |
| +are "add", "old", "access" or "del", the MAC |
| address of the host (or "<null>"), the IP address, and the hostname, |
| if known. "add" means a lease has been created, "del" means it has |
| been destroyed, "old" is a notification of an existing lease when |
| dnsmasq starts or a change to MAC address or hostname of an existing |
| lease (also, lease length or expiry and client-id, if leasefile-ro is set). |
| +The "access" keyword means that a request was just received and depending |
| +on the script exit status request for address will be granted, if exit status |
| +is zero or not if it is non-zero. |
| The process is run as root (assuming that dnsmasq was originally run as |
| root) even if dnsmasq is configured to change UID to an unprivileged user. |
| The environment is inherited from the invoker of dnsmasq, and if the |