diff options
| author | Guy Harris <gharris@sonic.net> | 2022-02-04 15:30:28 -0800 |
|---|---|---|
| committer | Guy Harris <gharris@sonic.net> | 2022-02-04 15:30:28 -0800 |
| commit | 3eca6924ac341cfe9222f547b253364995a3f3ea (patch) | |
| tree | c3e8093e268d2f6fc6bded172aca6b5799391a71 /pcap-linux.c | |
| parent | 9d928eb03f158ea93e6236592509bfa2885b9684 (diff) | |
linux: print a better message for "out of memory" errors for kernel filters.
If attempting to set a kernel filter gets ENOMEM, print a message
suggesting that they increase the value of the net.core.optmem_max
sysctl.
See GitHub issue #1089 for an example of a complicated but not too
complicated filter that exceeds the default "other/option memory per
socket" maximum.
Diffstat (limited to 'pcap-linux.c')
| -rw-r--r-- | pcap-linux.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/pcap-linux.c b/pcap-linux.c index bd8f2b24..13851322 100644 --- a/pcap-linux.c +++ b/pcap-linux.c @@ -4410,7 +4410,18 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) * the filter for a reason other than "this kernel * isn't configured to support socket filters. */ - if (errno != ENOPROTOOPT && errno != EOPNOTSUPP) { + if (errno == ENOMEM) { + /* + * Either a kernel memory allocation + * failure occurred, or there's too + * much "other/option memory" allocated + * for this socket. Suggest that they + * increase the "other/option memory" + * limit. + */ + fprintf(stderr, + "Warning: Couldn't allocate kernel memory for filter: try increasing net.core.optmem_max with sysctl\n"); + } else if (errno != ENOPROTOOPT && errno != EOPNOTSUPP) { fprintf(stderr, "Warning: Kernel filter failed: %s\n", pcap_strerror(errno)); |