Babeld will exit with a fatal error if it is unable to write sysctls. When running in a container, however, /proc/sys may be mounted read-only, which causes babeld to fail.
This adds a switch to consider sysctl failures as non-fatal, in which case a warning will be issues rather than having the daemon fail to start. Signed-off-by: Toke Høiland-Jørgensen <[email protected]> --- babeld.c | 8 ++++++-- babeld.h | 1 + babeld.man | 12 ++++++++++++ configuration.c | 3 +++ kernel_netlink.c | 7 ++++++- 5 files changed, 28 insertions(+), 3 deletions(-) diff --git a/babeld.c b/babeld.c index 943f042..45b14fa 100644 --- a/babeld.c +++ b/babeld.c @@ -67,6 +67,7 @@ int default_wired_hello_interval = -1; int resend_delay = -1; int random_id = 0; int do_daemonise = 0; +int sysctl_nonfatal = 0; const char *logfile = NULL, *pidfile = "/var/run/babeld.pid", *state_file = "/var/lib/babel-state"; @@ -128,7 +129,7 @@ main(int argc, char **argv) while(1) { opt = getopt(argc, argv, - "m:p:h:H:i:k:A:srR:uS:d:g:lwz:M:t:T:c:C:DL:I:"); + "m:p:h:H:i:k:A:srR:uS:d:g:lwz:M:t:T:c:C:DL:I:F"); if(opt < 0) break; @@ -263,6 +264,9 @@ main(int argc, char **argv) case 'D': do_daemonise = 1; break; + case 'F': + sysctl_nonfatal = 1; + break; case 'L': logfile = optarg; break; @@ -800,7 +804,7 @@ main(int argc, char **argv) " " "[-t table] [-T table] [-c file] [-C statement]\n" " " - "[-d level] [-D] [-L logfile] [-I pidfile]\n" + "[-d level] [-D] [-F] [-L logfile] [-I pidfile]\n" " " "[id] interface...\n", argv[0]); diff --git a/babeld.h b/babeld.h index 92ce9b5..c1f26fe 100644 --- a/babeld.h +++ b/babeld.h @@ -86,6 +86,7 @@ extern time_t reboot_time; extern int default_wireless_hello_interval, default_wired_hello_interval; extern int resend_delay; extern int random_id; +extern int sysctl_nonfatal; extern int do_daemonise; extern const char *logfile, *pidfile, *state_file; extern int link_detect; diff --git a/babeld.man b/babeld.man index ec600c2..7182f30 100644 --- a/babeld.man +++ b/babeld.man @@ -135,6 +135,11 @@ Specify a configuration statement directly on the command line. .B \-D Daemonise at startup. .TP +.B \-F +Don't consider failures writing to sysctl as fatal. Warn of the failures, but +continue running. This is useful when running babeld in a container that mounts +/proc/sys as read-only (as systemd-nspawn does, for instance). +.TP .BI \-L " logfile" Specify a file to log random ``how do you do?'' messages to. This defaults to standard error if not daemonising, and to @@ -253,6 +258,13 @@ This specifies whether to daemonize at startup, and is equivalent to the command-line option .BR \-D . .TP +.BR sysctl-nonfatal " {" true | false } +This controls whether to consider failures writing to sysctl as fatal. If set, +warn of the failures, but continue running. This is useful when running babeld +in a container that mounts /proc/sys as read-only (as systemd-nspawn does, for +instance). Equivalent to the command line option +.BR \-F . +.TP .BI state-file " filename" This specifies the name of the file used for preserving long-term information between invocations of the diff --git a/configuration.c b/configuration.c index 6a9c09d..571e220 100644 --- a/configuration.c +++ b/configuration.c @@ -691,6 +691,7 @@ parse_option(int c, gnc_t gnc, void *closure, char *token) strcmp(token, "link-detect") == 0 || strcmp(token, "random-id") == 0 || strcmp(token, "daemonise") == 0 || + strcmp(token, "sysctl-nonfatal") == 0 || strcmp(token, "ipv6-subtrees") == 0 || strcmp(token, "reflect-kernel-metric") == 0) { int b; @@ -706,6 +707,8 @@ parse_option(int c, gnc_t gnc, void *closure, char *token) random_id = b; else if(strcmp(token, "daemonise") == 0) do_daemonise = b; + else if(strcmp(token, "sysctl-nonfatal") == 0) + sysctl_nonfatal = b; else if(strcmp(token, "ipv6-subtrees") == 0) has_ipv6_subtrees = b; else if(strcmp(token, "reflect-kernel-metric") == 0) diff --git a/kernel_netlink.c b/kernel_netlink.c index ab63d33..0154c63 100644 --- a/kernel_netlink.c +++ b/kernel_netlink.c @@ -183,8 +183,13 @@ write_proc(char *filename, int value) n = snprintf(buf, 100, "%d", value); fd = open(filename, O_WRONLY); - if(fd < 0) + if(fd < 0 && sysctl_nonfatal) { + fprintf(stderr, "Warning: writing sysctl %s failed (non-fatal): %s.\n", + filename, strerror(errno)); + return 1; + } else if(fd < 0) { return -1; + } rc = write(fd, buf, n); if(rc < n) { -- 2.5.0 _______________________________________________ Babel-users mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/babel-users
