/* * netsniff-ng - the packet sniffing beast * Copyright 2011 - 2013 Daniel Borkmann. * Subject to the GPL, version 2. */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include "pcap_io.h" #include "built_in.h" #include "ioops.h" #include "iosched.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 __maybe_unused, 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) > (off_t) 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) > (off_t) 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) + (RUNTIME_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(NULL, 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(NULL, 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 void pcap_mm_init_once(bool enforce_prio) { if (enforce_prio) set_ioprio_be(); } static int pcap_mm_prepare_access(int fd, enum pcap_mode mode, bool jumbo) { 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 __maybe_unused) { 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 = { .init_once_pcap = pcap_mm_init_once, .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, }; /Documentation/device-mapper/log-writes.txt parente34bac726d27056081d0250c0e173e4b155aa340 (diff)parent868c97a846a73e937d835b09b8c885a69df50ec8 (diff)
Merge tag 'docs-4.10' of git://git.lwn.net/linuxHEADmaster
Pull documentation update from Jonathan Corbet: "These are the documentation changes for 4.10. It's another busy cycle for the docs tree, as the sphinx conversion continues. Highlights include: - Further work on PDF output, which remains a bit of a pain but should be more solid now. - Five more DocBook template files converted to Sphinx. Only 27 to go... Lots of plain-text files have also been converted and integrated. - Images in binary formats have been replaced with more source-friendly versions. - Various bits of organizational work, including the renaming of various files discussed at the kernel summit. - New documentation for the device_link mechanism. ... and, of course, lots of typo fixes and small updates" * tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits) dma-buf: Extract dma-buf.rst Update Documentation/00-INDEX docs: 00-INDEX: document directories/files with no docs docs: 00-INDEX: remove non-existing entries docs: 00-INDEX: add missing entries for documentation files/dirs docs: 00-INDEX: consolidate process/ and admin-guide/ description scripts: add a script to check if Documentation/00-INDEX is sane Docs: change sh -> awk in REPORTING-BUGS Documentation/core-api/device_link: Add initial documentation core-api: remove an unexpected unident ppc/idle: Add documentation for powersave=off Doc: Correct typo, "Introdution" => "Introduction" Documentation/atomic_ops.txt: convert to ReST markup Documentation/local_ops.txt: convert to ReST markup Documentation/assoc_array.txt: convert to ReST markup docs-rst: parse-headers.pl: cleanup the documentation docs-rst: fix media cleandocs target docs-rst: media/Makefile: reorganize the rules docs-rst: media: build SVG from graphviz files docs-rst: replace bayer.png by a SVG image ...
Diffstat (limited to 'Documentation/device-mapper/log-writes.txt')