diff options
| author | Roy Marples <roy@marples.name> | 2020-05-15 20:23:55 +0100 |
|---|---|---|
| committer | Roy Marples <roy@marples.name> | 2020-05-15 20:23:55 +0100 |
| commit | e591578fa167bd838c8a0051eadf0a33062cbb06 (patch) | |
| tree | 88f5815dc4c6c3d43479bb7ff390759d756b1e1d /src/privsep-bpf.c | |
| parent | 529a6092e6ada5a185cb2baefdf509a6c24678ec (diff) | |
| download | dhcpcd-e591578fa167bd838c8a0051eadf0a33062cbb06.tar.xz | |
BPF: Set write filters where supported
While here make Capsicum and Pledge more granular so we can
easily Pledge the BPF BOOTP process but not the ARP one.
Diffstat (limited to 'src/privsep-bpf.c')
| -rw-r--r-- | src/privsep-bpf.c | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/src/privsep-bpf.c b/src/privsep-bpf.c index 8326425d..06247c0f 100644 --- a/src/privsep-bpf.c +++ b/src/privsep-bpf.c @@ -203,7 +203,6 @@ ps_bpf_cmd(struct dhcpcd_ctx *ctx, struct ps_msghdr *psm, struct msghdr *msg) struct iovec *iov = msg->msg_iov; struct interface *ifp; struct ipv4_state *istate; - unsigned int flags = PSF_DROPPRIVS | PSF_CAP_ENTER; cmd = (uint16_t)(psm->ps_cmd & ~(PS_START | PS_STOP)); psp = ps_findprocess(ctx, &psm->ps_id); @@ -257,19 +256,12 @@ ps_bpf_cmd(struct dhcpcd_ctx *ctx, struct ps_msghdr *psm, struct msghdr *msg) psp->psp_proto = ETHERTYPE_ARP; psp->psp_protostr = "ARP"; psp->psp_filter = bpf_arp; - /* - * Pledge is currently useless for BPF ARP because we cannot - * change the filter: - * http://openbsd-archive.7691.n7.nabble.com/ \ - * pledge-bpf-32bit-arch-unbreak-td299901.html - */ break; #endif case PS_BPF_BOOTP: psp->psp_proto = ETHERTYPE_IP; psp->psp_protostr = "BOOTP"; psp->psp_filter = bpf_bootp; - flags |= PSF_PLEDGE; break; } @@ -277,12 +269,21 @@ ps_bpf_cmd(struct dhcpcd_ctx *ctx, struct ps_msghdr *psm, struct msghdr *msg) &psp->psp_pid, &psp->psp_fd, ps_bpf_recvmsg, NULL, psp, ps_bpf_start_bpf, ps_bpf_signal_bpfcb, - flags); + PSF_DROPPRIVS); switch (start) { case -1: ps_freeprocess(psp); return -1; case 0: +#ifdef HAVE_CAPSICUM + if (cap_enter() == -1 && errno != ENOSYS) + logerr("%s: cap_enter", __func__); +#endif +#ifdef HAVE_PLEDGE + /* Cant change BPF fitler for ARP yet. */ + if (cmd != PS_BPF_ARP && pledge("stdio", NULL) == -1) + logerr("%s: pledge", __func__); +#endif break; default: #ifdef PRIVSEP_DEBUG |