mirror of
https://passt.top/passt
synced 2024-12-22 21:55:22 +00:00
9a175cc2ce
Based on a patch from Giuseppe Scrivano, this adds the ability to: - specify paths and names of target namespaces to join, instead of a PID, also for user namespaces, with --userns - request to join or create a network namespace only, without entering or creating a user namespace, with --netns-only - specify the base directory for netns mountpoints, with --nsrun-dir Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> [sbrivio: reworked logic to actually join the given namespaces when they're not created, implemented --netns-only and --nsrun-dir, updated pasta demo script and man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
199 lines
4.1 KiB
C
199 lines
4.1 KiB
C
// SPDX-License-Identifier: AGPL-3.0-or-later
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/* PASST - Plug A Simple Socket Transport
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* for qemu/UNIX domain socket mode
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*
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* PASTA - Pack A Subtle Tap Abstraction
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* for network namespace/tap device mode
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*
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* pcap.c - Packet capture for PASST/PASTA
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*
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* Copyright (c) 2021 Red Hat GmbH
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* Author: Stefano Brivio <sbrivio@redhat.com>
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*/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <time.h>
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#include <net/ethernet.h>
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#include <netinet/in.h>
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#include <unistd.h>
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#include <net/if.h>
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#include "util.h"
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#include "passt.h"
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#define PCAP_PREFIX "/tmp/passt_"
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#define PCAP_PREFIX_PASTA "/tmp/pasta_"
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#define PCAP_ISO8601_FORMAT "%FT%H:%M:%SZ"
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#define PCAP_ISO8601_STR "YYYY-MM-ddTHH:mm:ssZ"
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#define PCAP_VERSION_MINOR 4
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static int pcap_fd = -1;
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/* See pcap.h from libpcap, or pcap-savefile(5) */
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static struct {
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uint32_t magic;
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#define PCAP_MAGIC 0xa1b2c3d4
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uint16_t major;
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#define PCAP_VERSION_MAJOR 2
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uint16_t minor;
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#define PCAP_VERSION_MINOR 4
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int32_t thiszone;
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uint32_t sigfigs;
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uint32_t snaplen;
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uint32_t linktype;
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#define PCAP_LINKTYPE_ETHERNET 1
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} pcap_hdr = {
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PCAP_MAGIC, PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR, 0, 0, ETH_MAX_MTU,
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PCAP_LINKTYPE_ETHERNET
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};
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struct pcap_pkthdr {
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uint32_t tv_sec;
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uint32_t tv_usec;
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uint32_t caplen;
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uint32_t len;
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};
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/**
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* pcap() - Capture a single frame to pcap file
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* @pkt: Pointer to data buffer, including L2 headers
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* @len: L2 packet length
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*/
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void pcap(char *pkt, size_t len)
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{
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struct pcap_pkthdr h;
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struct timeval tv;
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if (pcap_fd == -1)
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return;
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gettimeofday(&tv, NULL);
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h.tv_sec = tv.tv_sec;
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h.tv_usec = tv.tv_usec;
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h.caplen = h.len = len;
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write(pcap_fd, &h, sizeof(h));
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write(pcap_fd, pkt, len);
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}
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/**
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* pcapm() - Capture multiple frames from message header to pcap file
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* @mh: Pointer to sendmsg() message header buffer
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*/
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void pcapm(struct msghdr *mh)
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{
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struct pcap_pkthdr h;
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struct timeval tv;
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unsigned int i;
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if (pcap_fd == -1)
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return;
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gettimeofday(&tv, NULL);
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h.tv_sec = tv.tv_sec;
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h.tv_usec = tv.tv_usec;
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for (i = 0; i < mh->msg_iovlen; i++) {
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struct iovec *iov = &mh->msg_iov[i];
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h.caplen = h.len = iov->iov_len - 4;
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write(pcap_fd, &h, sizeof(h));
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write(pcap_fd, (char *)iov->iov_base + 4, iov->iov_len - 4);
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}
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}
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/**
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* pcapm() - Capture multiple frames from multiple message headers to pcap file
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* @mmh: Pointer to first sendmmsg() header
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*/
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void pcapmm(struct mmsghdr *mmh, unsigned int vlen)
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{
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struct pcap_pkthdr h;
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struct timeval tv;
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unsigned int i, j;
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if (pcap_fd == -1)
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return;
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gettimeofday(&tv, NULL);
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h.tv_sec = tv.tv_sec;
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h.tv_usec = tv.tv_usec;
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for (i = 0; i < vlen; i++) {
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struct msghdr *mh = &mmh[i].msg_hdr;
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for (j = 0; j < mh->msg_iovlen; j++) {
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struct iovec *iov = &mh->msg_iov[j];
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h.caplen = h.len = iov->iov_len - 4;
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write(pcap_fd, &h, sizeof(h));
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write(pcap_fd, (char *)iov->iov_base + 4,
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iov->iov_len - 4);
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}
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}
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}
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/**
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* pcap_init() - Initialise pcap file
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* @c: Execution context
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* @index: pcap name index: passt instance number or pasta netns socket
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*/
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void pcap_init(struct ctx *c, int index)
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{
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char name[] = PCAP_PREFIX PCAP_ISO8601_STR STR(UINT_MAX) ".pcap";
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struct timeval tv;
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struct tm *tm;
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if (pcap_fd != -1)
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return;
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if (!*c->pcap)
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return;
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if (*c->pcap == 1) {
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if (c->mode == MODE_PASTA)
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memcpy(name, PCAP_PREFIX_PASTA,
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sizeof(PCAP_PREFIX_PASTA));
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gettimeofday(&tv, NULL);
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tm = localtime(&tv.tv_sec);
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strftime(name + strlen(PCAP_PREFIX),
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sizeof(PCAP_ISO8601_STR) - 1, PCAP_ISO8601_FORMAT, tm);
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snprintf(name + strlen(PCAP_PREFIX) + strlen(PCAP_ISO8601_STR),
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sizeof(name) - strlen(PCAP_PREFIX) -
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strlen(PCAP_ISO8601_STR),
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"_%i.pcap", index);
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strncpy(c->pcap, name, PATH_MAX);
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}
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pcap_fd = open(c->pcap, O_WRONLY | O_CREAT | O_TRUNC,
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S_IRUSR | S_IWUSR);
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if (pcap_fd == -1) {
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perror("open");
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return;
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}
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info("Saving packet capture at %s", c->pcap);
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write(pcap_fd, &pcap_hdr, sizeof(pcap_hdr));
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}
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