3d306bffc
Denys Vlasenko
2018-03-11
Subject
udhcpd: clamp down huge auto_times to ~2M seconds, better EINTR poll handling
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
networking/udhcp/dhcpd.c+20 -5
| @@ -853,6 +853,9 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) | |
| /* Would rather not do read_config before daemonization - | |
| * otherwise NOMMU machines will parse config twice */ | |
| read_config(argv[0] ? argv[0] : DHCPD_CONF_FILE); | |
| + | /* prevent poll timeout overflow */ |
| + | if (server_config.auto_time > INT_MAX / 1000) |
| + | server_config.auto_time = INT_MAX / 1000; |
| /* Make sure fd 0,1,2 are open */ | |
| bb_sanitize_stdio(); | |
| @@ -914,14 +917,26 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) | |
| } | |
| udhcp_sp_fd_set(pfds, server_socket); | |
| - | tv = timeout_end - monotonic_sec(); |
| - | /* Block here waiting for either signal or packet */ |
| - | retval = safe_poll(pfds, 2, server_config.auto_time ? tv * 1000 : -1); |
| - | if (retval <= 0) { |
| - | if (retval == 0) { |
| + | |
| + | new_tv: |
| + | tv = -1; |
| + | if (server_config.auto_time) { |
| + | tv = timeout_end - monotonic_sec(); |
| + | if (tv <= 0) { |
| + | write_leases: |
| write_leases(); | |
| goto continue_with_autotime; | |
| } | |
| + | tv *= 1000; |
| + | } |
| + | |
| + | /* Block here waiting for either signal or packet */ |
| + | retval = poll(pfds, 2, tv); |
| + | if (retval <= 0) { |
| + | if (retval == 0) |
| + | goto write_leases; |
| + | if (errno == EINTR) |
| + | goto new_tv; |
| /* < 0 and not EINTR: should not happen */ | |
| bb_perror_msg_and_die("poll"); | |
| } | |