diff options
Diffstat (limited to 'pcap.c')
| -rw-r--r-- | pcap.c | 111 |
1 files changed, 62 insertions, 49 deletions
@@ -33,32 +33,12 @@ #include "log.h" #include "pcap.h" #include "iov.h" +#include "tap.h" +#include "serialise.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 -}; +int pcap_fd = -1; struct pcap_pkthdr { uint32_t tv_sec; @@ -72,25 +52,28 @@ struct pcap_pkthdr { * @iov: IO vector containing frame (with L2 headers and tap headers) * @iovcnt: Number of buffers (@iov entries) in frame * @offset: Byte offset of the L2 headers within @iov + * @l2len: Length of L2 frame data to capture * @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 offset, size_t l2len, const struct timespec *now) { - 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 = 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) + if (write_all_buf(pcap_fd, &h, sizeof(h)) < 0) { + debug_perror("Cannot log packet, packet header error"); + return; + } + + if (write_remainder(pcap_fd, iov, iovcnt, offset, l2len) < 0) { debug_perror("Cannot log packet, length %zu", l2len); + return; + } } /** @@ -98,16 +81,19 @@ static void pcap_frame(const struct iovec *iov, size_t iovcnt, * @pkt: Pointer to data buffer, including L2 headers * @l2len: L2 frame length */ +/* cppcheck-suppress unusedFunction */ void pcap(const char *pkt, size_t l2len) { struct iovec iov = { (char *)pkt, l2len }; - struct timespec now; + struct timespec now = { 0 }; if (pcap_fd == -1) return; - clock_gettime(CLOCK_REALTIME, &now); - pcap_frame(&iov, 1, 0, &now); + if (clock_gettime(CLOCK_REALTIME, &now)) + err_perror("Failed to get CLOCK_REALTIME time"); + + pcap_frame(&iov, 1, 0, l2len, &now); } /** @@ -120,36 +106,43 @@ void pcap(const char *pkt, size_t l2len) 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); + for (i = 0; i < n; i++) { + pcap_frame(iov + i * frame_parts, frame_parts, offset, + iov_size(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 + * @l2len: Length of L2 frame data to capture */ -/* 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, + size_t l2len) { - 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, l2len, &now); } /** @@ -158,7 +151,28 @@ 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; @@ -166,10 +180,9 @@ 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; } |