diff options
Diffstat (limited to 'trafgen_dev.c')
| -rw-r--r-- | trafgen_dev.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/trafgen_dev.c b/trafgen_dev.c new file mode 100644 index 0000000..cd99a0c --- /dev/null +++ b/trafgen_dev.c @@ -0,0 +1,258 @@ +/* + * netsniff-ng - the packet sniffing beast + * Copyright 2011 - 2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>, + * Swiss federal institute of technology (ETH Zurich) + * Subject to the GPL, version 2. + */ + +#define _GNU_SOURCE + +#include <fcntl.h> +#include <sys/stat.h> +#include <string.h> +#include <net/ethernet.h> + +#include "sock.h" +#include "xmalloc.h" +#include "pcap_io.h" +#include "built_in.h" +#include "trafgen_dev.h" + +static int dev_pcap_open(struct dev_io *dev, const char *name, enum dev_io_mode_t mode) +{ + dev->pcap_magic = ORIGINAL_TCPDUMP_MAGIC; + dev->pcap_ops = pcap_ops[PCAP_OPS_SG]; + + if (mode == DEV_IO_IN) { + if (!strncmp("-", name, strlen("-"))) { + dev->fd = dup_or_die(fileno(stdin)); + close(fileno(stdin)); + } else { + dev->fd = open(name, O_RDONLY | O_LARGEFILE | O_NOATIME); + if (dev->fd < 0 && errno == EPERM) + dev->fd = open_or_die(name, O_RDONLY | O_LARGEFILE); + } + + dev->pcap_mode = PCAP_MODE_RD; + } else if (mode & DEV_IO_OUT) { + if (!strncmp("-", name, strlen("-"))) { + dev->fd = dup_or_die(fileno(stdout)); + close(fileno(stdout)); + } else { + dev->fd = open_or_die_m(name, O_RDWR | O_CREAT | O_TRUNC | + O_LARGEFILE, DEFFILEMODE); + } + + dev->pcap_mode = PCAP_MODE_WR; + } else { + bug(); + } + + if (dev->fd < 0) + panic("pcap_dev: Cannot open file %s! %s.\n", name, strerror(errno)); + + if (dev->pcap_ops->init_once_pcap) + dev->pcap_ops->init_once_pcap(false); + + if (mode == DEV_IO_IN) { + if (dev->pcap_ops->pull_fhdr_pcap(dev->fd, &dev->pcap_magic, &dev->link_type)) + panic("Error reading pcap header!\n"); + } + + if (dev->pcap_ops->prepare_access_pcap) { + if (dev->pcap_ops->prepare_access_pcap(dev->fd, dev->pcap_mode, false)) + panic("Error prepare reading pcap!\n"); + } + + return 0; +} + +static int dev_pcap_read(struct dev_io *dev, uint8_t *buf, size_t len, + struct timespec *tstamp) +{ + pcap_pkthdr_t phdr; + size_t pkt_len; + + if (dev->pcap_ops->read_pcap(dev->fd, &phdr, dev->pcap_magic, buf, len) <= 0) + return -1; + + pkt_len = pcap_get_length(&phdr, dev->pcap_magic); + if (!pkt_len) + return -1; + + pcap_get_tstamp(&phdr, dev->pcap_magic, tstamp); + + return pkt_len; +} + +static int dev_pcap_write(struct dev_io *dev, const uint8_t *buf, size_t len) +{ + struct timeval time; + pcap_pkthdr_t phdr; + int ret; + + /* Write PCAP file header only once */ + if (!dev->is_initialized) { + if (dev->pcap_ops->push_fhdr_pcap(dev->fd, dev->pcap_magic, dev->link_type)) { + fprintf(stderr, "Error writing pcap header!\n"); + return -1; + } + + if (dev->pcap_ops->prepare_access_pcap) { + if (dev->pcap_ops->prepare_access_pcap(dev->fd, PCAP_MODE_WR, true)) { + fprintf(stderr, "Error prepare writing pcap!\n"); + return -1; + } + } + + dev->is_initialized = true; + } + + bug_on(gettimeofday(&time, NULL)); + + phdr.ppo.ts.tv_sec = time.tv_sec; + phdr.ppo.ts.tv_usec = time.tv_usec; + phdr.ppo.caplen = len; + phdr.ppo.len = len; + + ret = dev->pcap_ops->write_pcap(dev->fd, &phdr, dev->pcap_magic, + buf, pcap_get_length(&phdr, dev->pcap_magic)); + + if (unlikely(ret != (int) pcap_get_total_length(&phdr, dev->pcap_magic))) { + fprintf(stderr, "Write error to pcap!\n"); + return -1; + } + + return ret; +} + +static void dev_pcap_close(struct dev_io *dev) +{ + if (dev->pcap_mode == PCAP_MODE_WR) + dev->pcap_ops->fsync_pcap(dev->fd); + + if (dev->pcap_ops->prepare_close_pcap) + dev->pcap_ops->prepare_close_pcap(dev->fd, dev->pcap_mode); + + close(dev->fd); +} + +static const struct dev_io_ops dev_pcap_ops = { + .open = dev_pcap_open, + .read = dev_pcap_read, + .write = dev_pcap_write, + .close = dev_pcap_close, +}; + +static int dev_net_open(struct dev_io *dev, const char *name, enum dev_io_mode_t mode) +{ + dev->ifindex = __device_ifindex(name); + dev->dev_type = device_type(name); + dev->fd = pf_socket(); + + return 0; +} + +static int dev_net_write(struct dev_io *dev, const uint8_t *buf, size_t len) +{ + struct sockaddr_ll saddr = { + .sll_family = PF_PACKET, + .sll_halen = ETH_ALEN, + .sll_ifindex = dev->ifindex, + }; + + return sendto(dev->fd, buf, len, 0, (struct sockaddr *) &saddr, sizeof(saddr)); +} + +static const struct dev_io_ops dev_net_ops = { + .open = dev_net_open, + .write = dev_net_write, +}; + +struct dev_io *dev_io_open(const char *name, enum dev_io_mode_t mode) +{ + struct dev_io *dev = xzmalloc(sizeof(struct dev_io)); + + if (strstr(name, ".pcap")) { + dev->ops = &dev_pcap_ops; + } else if (device_mtu(name) > 0) { + dev->ops = &dev_net_ops; + } else { + fprintf(stderr, "No networking device or pcap file: %s\n", name); + return NULL; + } + + if (dev->ops->open) { + if (dev->ops->open(dev, name, mode)) { + xfree(dev); + return NULL; + } + } + + dev->name = xstrdup(name); + return dev; +}; + +int dev_io_write(struct dev_io *dev, const uint8_t *buf, size_t len) +{ + bug_on(!dev); + bug_on(!dev->ops); + + if (dev->ops->write) + return dev->ops->write(dev, buf, len); + + return 0; +} + +int dev_io_read(struct dev_io *dev, uint8_t *buf, size_t len, + struct timespec *tstamp) +{ + bug_on(!dev); + bug_on(!dev->ops); + + if (dev->ops->read) + return dev->ops->read(dev, buf, len, tstamp); + + return 0; +} + +const char *dev_io_name_get(struct dev_io *dev) +{ + return dev->name; +} + +bool dev_io_is_netdev(struct dev_io *dev) +{ + return dev->ops == &dev_net_ops; +} + +bool dev_io_is_pcap(struct dev_io *dev) +{ + return dev->ops == &dev_pcap_ops; +} + +void dev_io_link_type_set(struct dev_io *dev, int link_type) +{ + dev->link_type = link_type; +} + +int dev_io_ifindex_get(struct dev_io *dev) +{ + return dev->ifindex; +} + +int dev_io_fd_get(struct dev_io *dev) +{ + return dev->fd; +} + +void dev_io_close(struct dev_io *dev) +{ + if (dev) { + if (dev->ops->close) + dev->ops->close(dev); + + free(dev->name); + free(dev); + } +} |