diff options
Diffstat (limited to 'pcap.c')
| -rw-r--r-- | pcap.c | 104 |
1 files changed, 51 insertions, 53 deletions
@@ -33,33 +33,12 @@ #include "log.h" #include "pcap.h" #include "iov.h" +#include "tap.h" #define PCAP_VERSION_MINOR 4 static int pcap_fd = -1; -/* See pcap.h from libpcap, or pcap-savefile(5) */ -static const struct { - uint32_t magic; -#define PCAP_MAGIC 0xa1b2c3d4 - - uint16_t major; -#define PCAP_VERSION_MAJOR 2 - - uint16_t minor; -#define PCAP_VERSION_MINOR 4 - - int32_t thiszone; - uint32_t sigfigs; - uint32_t snaplen; - - uint32_t linktype; -#define PCAP_LINKTYPE_ETHERNET 1 -} pcap_hdr = { - PCAP_MAGIC, PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR, 0, 0, ETH_MAX_MTU, - PCAP_LINKTYPE_ETHERNET -}; - struct pcap_pkthdr { uint32_t tv_sec; uint32_t tv_usec; @@ -73,42 +52,39 @@ struct pcap_pkthdr { * @iovcnt: Number of buffers (@iov entries) in frame * @offset: Byte offset of the L2 headers within @iov * @now: Timestamp - * - * Returns: 0 on success, -errno on error writing to the file */ static void pcap_frame(const struct iovec *iov, size_t iovcnt, size_t offset, const struct timespec *now) { - size_t len = iov_size(iov, iovcnt) - offset; + size_t l2len = iov_size(iov, iovcnt) - offset; struct pcap_pkthdr h = { .tv_sec = now->tv_sec, .tv_usec = DIV_ROUND_CLOSEST(now->tv_nsec, 1000), - .caplen = len, - .len = len + .caplen = l2len, + .len = l2len }; - struct iovec hiov = { &h, sizeof(h) }; - if (write_remainder(pcap_fd, &hiov, 1, 0) < 0 || - write_remainder(pcap_fd, iov, iovcnt, offset) < 0) { - debug("Cannot log packet, length %zu: %s", - len, strerror(errno)); - } + if (write_all_buf(pcap_fd, &h, sizeof(h)) < 0 || + write_remainder(pcap_fd, iov, iovcnt, offset) < 0) + debug_perror("Cannot log packet, length %zu", l2len); } /** * pcap() - Capture a single frame to pcap file * @pkt: Pointer to data buffer, including L2 headers - * @len: L2 packet length + * @l2len: L2 frame length */ -void pcap(const char *pkt, size_t len) +void pcap(const char *pkt, size_t l2len) { - struct iovec iov = { (char *)pkt, len }; - struct timespec now; + struct iovec iov = { (char *)pkt, l2len }; + struct timespec now = { 0 }; if (pcap_fd == -1) return; - clock_gettime(CLOCK_REALTIME, &now); + if (clock_gettime(CLOCK_REALTIME, &now)) + err_perror("Failed to get CLOCK_REALTIME time"); + pcap_frame(&iov, 1, 0, &now); } @@ -122,36 +98,38 @@ void pcap(const char *pkt, size_t len) void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n, size_t offset) { - struct timespec now; + struct timespec now = { 0 }; unsigned int i; if (pcap_fd == -1) return; - clock_gettime(CLOCK_REALTIME, &now); + if (clock_gettime(CLOCK_REALTIME, &now)) + err_perror("Failed to get CLOCK_REALTIME time"); for (i = 0; i < n; i++) pcap_frame(iov + i * frame_parts, frame_parts, offset, &now); } -/* - * pcap_iov - Write packet data described by an I/O vector +/** + * pcap_iov() - Write packet data described by an I/O vector * to a pcap file descriptor. - * * @iov: Pointer to the array of struct iovec describing the I/O vector * containing packet data to write, including L2 header * @iovcnt: Number of buffers (@iov entries) + * @offset: Offset of the L2 frame within the full data length */ -/* cppcheck-suppress unusedFunction */ -void pcap_iov(const struct iovec *iov, size_t iovcnt) +void pcap_iov(const struct iovec *iov, size_t iovcnt, size_t offset) { - struct timespec now; + struct timespec now = { 0 }; if (pcap_fd == -1) return; - clock_gettime(CLOCK_REALTIME, &now); - pcap_frame(iov, iovcnt, 0, &now); + if (clock_gettime(CLOCK_REALTIME, &now)) + err_perror("Failed to get CLOCK_REALTIME time"); + + pcap_frame(iov, iovcnt, offset, &now); } /** @@ -160,7 +138,28 @@ void pcap_iov(const struct iovec *iov, size_t iovcnt) */ void pcap_init(struct ctx *c) { - int flags = O_WRONLY | O_CREAT | O_TRUNC; + /* See pcap.h from libpcap, or pcap-savefile(5) */ +#define PCAP_MAGIC 0xa1b2c3d4 +#define PCAP_VERSION_MAJOR 2 +#define PCAP_VERSION_MINOR 4 +#define PCAP_LINKTYPE_ETHERNET 1 + const struct { + uint32_t magic; + uint16_t major; + uint16_t minor; + + int32_t thiszone; + uint32_t sigfigs; + uint32_t snaplen; + + uint32_t linktype; + } pcap_hdr = { + .magic = PCAP_MAGIC, + .major = PCAP_VERSION_MAJOR, + .minor = PCAP_VERSION_MINOR, + .snaplen = tap_l2_max_len(c), + .linktype = PCAP_LINKTYPE_ETHERNET + }; if (pcap_fd != -1) return; @@ -168,15 +167,14 @@ void pcap_init(struct ctx *c) if (!*c->pcap) return; - flags |= c->foreground ? O_CLOEXEC : 0; - pcap_fd = open(c->pcap, flags, S_IRUSR | S_IWUSR); + pcap_fd = output_file_open(c->pcap, O_WRONLY); if (pcap_fd == -1) { - perror("open"); + err_perror("Couldn't open pcap file %s", c->pcap); return; } info("Saving packet capture to %s", c->pcap); if (write(pcap_fd, &pcap_hdr, sizeof(pcap_hdr)) < 0) - warn("Cannot write PCAP header: %s", strerror(errno)); + warn_perror("Cannot write PCAP header"); } |