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authorDaniel Borkmann <dborkman@redhat.com>2013-03-15 10:41:48 +0100
committerDaniel Borkmann <dborkman@redhat.com>2013-03-15 10:41:48 +0100
commit1a9fbac03c684f29cff9ac44875bd9504a89f54e (patch)
tree1b2e40dbe5dc1899ef5b62c4325c9b94c9c450fc /pcap_mm.c
all: import netsniff-ng 0.5.8-rc0 source
We decided to get rid of the old Git history and start a new one for several reasons: *) Allow / enforce only high-quality commits (which was not the case for many commits in the history), have a policy that is more close to the one from the Linux kernel. With high quality commits, we mean code that is logically split into commits and commit messages that are signed-off and have a proper subject and message body. We do not allow automatic Github merges anymore, since they are total bullshit. However, we will either cherry-pick your patches or pull them manually. *) The old archive was about ~27MB for no particular good reason. This basically derived from the bad decision that also some PDF files where stored there. From this moment onwards, no binary objects are allowed to be stored in this repository anymore. The old archive is not wiped away from the Internet. You will still be able to find it, e.g. on git.cryptoism.org etc. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Diffstat (limited to 'pcap_mm.c')
-rw-r--r--pcap_mm.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/pcap_mm.c b/pcap_mm.c
new file mode 100644
index 0000000..f3b3fd0
--- /dev/null
+++ b/pcap_mm.c
@@ -0,0 +1,197 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2011 - 2013 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+
+#include "pcap_io.h"
+#include "xio.h"
+#include "xutils.h"
+#include "built_in.h"
+
+static size_t map_size = 0;
+static char *ptr_va_start, *ptr_va_curr;
+
+static void __pcap_mmap_write_need_remap(int fd)
+{
+ int ret;
+ off_t pos, map_size_old = map_size;
+ off_t offset = ptr_va_curr - ptr_va_start;
+
+ map_size = PAGE_ALIGN(map_size_old * 10 / 8);
+
+ pos = lseek(fd, map_size, SEEK_SET);
+ if (pos < 0)
+ panic("Cannot lseek pcap file!\n");
+
+ ret = write_or_die(fd, "", 1);
+ if (ret != 1)
+ panic("Cannot write file!\n");
+
+ ptr_va_start = mremap(ptr_va_start, map_size_old, map_size, MREMAP_MAYMOVE);
+ if (ptr_va_start == MAP_FAILED)
+ panic("mmap of file failed!");
+
+ ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL);
+ if (ret < 0)
+ panic("Failed to give kernel mmap advise!\n");
+
+ ptr_va_curr = ptr_va_start + offset;
+}
+
+static ssize_t pcap_mm_write(int fd, pcap_pkthdr_t *phdr, enum pcap_type type,
+ const uint8_t *packet, size_t len)
+{
+ size_t hdrsize = pcap_get_hdr_length(phdr, type);
+
+ if ((off_t) (ptr_va_curr - ptr_va_start) + hdrsize + len > map_size)
+ __pcap_mmap_write_need_remap(fd);
+
+ fmemcpy(ptr_va_curr, &phdr->raw, hdrsize);
+ ptr_va_curr += hdrsize;
+ fmemcpy(ptr_va_curr, packet, len);
+ ptr_va_curr += len;
+
+ return hdrsize + len;
+}
+
+static ssize_t pcap_mm_read(int fd, pcap_pkthdr_t *phdr, enum pcap_type type,
+ uint8_t *packet, size_t len)
+{
+ size_t hdrsize = pcap_get_hdr_length(phdr, type), hdrlen;
+
+ if (unlikely((off_t) (ptr_va_curr + hdrsize - ptr_va_start) > map_size))
+ return -EIO;
+
+ fmemcpy(&phdr->raw, ptr_va_curr, hdrsize);
+ ptr_va_curr += hdrsize;
+ hdrlen = pcap_get_length(phdr, type);
+
+ if (unlikely((off_t) (ptr_va_curr + hdrlen - ptr_va_start) > map_size))
+ return -EIO;
+ if (unlikely(hdrlen == 0 || hdrlen > len))
+ return -EINVAL;
+
+ fmemcpy(packet, ptr_va_curr, hdrlen);
+ ptr_va_curr += hdrlen;
+
+ return hdrsize + hdrlen;
+}
+
+static inline off_t ____get_map_size(bool jumbo)
+{
+ int allocsz = jumbo ? 16 : 3;
+
+ return PAGE_ALIGN(sizeof(struct pcap_filehdr) + (PAGE_SIZE * allocsz) * 1024);
+}
+
+static void __pcap_mm_prepare_access_wr(int fd, bool jumbo)
+{
+ int ret;
+ off_t pos;
+ struct stat sb;
+
+ map_size = ____get_map_size(jumbo);
+
+ ret = fstat(fd, &sb);
+ if (ret < 0)
+ panic("Cannot fstat pcap file!\n");
+ if (!S_ISREG (sb.st_mode))
+ panic("pcap dump file is not a regular file!\n");
+
+ pos = lseek(fd, map_size, SEEK_SET);
+ if (pos < 0)
+ panic("Cannot lseek pcap file!\n");
+
+ ret = write_or_die(fd, "", 1);
+ if (ret != 1)
+ panic("Cannot write file!\n");
+
+ ptr_va_start = mmap(0, map_size, PROT_WRITE, MAP_SHARED, fd, 0);
+ if (ptr_va_start == MAP_FAILED)
+ panic("mmap of file failed!");
+ ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL);
+ if (ret < 0)
+ panic("Failed to give kernel mmap advise!\n");
+
+ ptr_va_curr = ptr_va_start + sizeof(struct pcap_filehdr);
+}
+
+static void __pcap_mm_prepare_access_rd(int fd)
+{
+ int ret;
+ struct stat sb;
+
+ ret = fstat(fd, &sb);
+ if (ret < 0)
+ panic("Cannot fstat pcap file!\n");
+ if (!S_ISREG (sb.st_mode))
+ panic("pcap dump file is not a regular file!\n");
+
+ map_size = sb.st_size;
+ ptr_va_start = mmap(0, map_size, PROT_READ, MAP_SHARED | MAP_LOCKED, fd, 0);
+ if (ptr_va_start == MAP_FAILED)
+ panic("mmap of file failed!");
+ ret = madvise(ptr_va_start, map_size, MADV_SEQUENTIAL);
+ if (ret < 0)
+ panic("Failed to give kernel mmap advise!\n");
+
+ ptr_va_curr = ptr_va_start + sizeof(struct pcap_filehdr);
+}
+
+static int pcap_mm_prepare_access(int fd, enum pcap_mode mode, bool jumbo)
+{
+ set_ioprio_be();
+
+ switch (mode) {
+ case PCAP_MODE_RD:
+ __pcap_mm_prepare_access_rd(fd);
+ break;
+ case PCAP_MODE_WR:
+ __pcap_mm_prepare_access_wr(fd, jumbo);
+ break;
+ default:
+ bug();
+ }
+
+ return 0;
+}
+
+static void pcap_mm_fsync(int fd)
+{
+ msync(ptr_va_start, (off_t) (ptr_va_curr - ptr_va_start), MS_ASYNC);
+}
+
+static void pcap_mm_prepare_close(int fd, enum pcap_mode mode)
+{
+ int ret;
+
+ ret = munmap(ptr_va_start, map_size);
+ if (ret < 0)
+ panic("Cannot unmap the pcap file!\n");
+
+ if (mode == PCAP_MODE_WR) {
+ ret = ftruncate(fd, (off_t) (ptr_va_curr - ptr_va_start));
+ if (ret)
+ panic("Cannot truncate the pcap file!\n");
+ }
+}
+
+const struct pcap_file_ops pcap_mm_ops = {
+ .pull_fhdr_pcap = pcap_generic_pull_fhdr,
+ .push_fhdr_pcap = pcap_generic_push_fhdr,
+ .prepare_access_pcap = pcap_mm_prepare_access,
+ .prepare_close_pcap = pcap_mm_prepare_close,
+ .read_pcap = pcap_mm_read,
+ .write_pcap = pcap_mm_write,
+ .fsync_pcap = pcap_mm_fsync,
+};