diff options
Diffstat (limited to 'lib/libprocstat/core.c')
| -rw-r--r-- | lib/libprocstat/core.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/lib/libprocstat/core.c b/lib/libprocstat/core.c new file mode 100644 index 000000000000..b27b35de3bab --- /dev/null +++ b/lib/libprocstat/core.c @@ -0,0 +1,516 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2013 Mikolaj Golub <trociny@FreeBSD.org> + * Copyright (c) 2017 Dell EMC + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/param.h> +#include <sys/elf.h> +#include <sys/exec.h> +#include <sys/ptrace.h> +#include <sys/user.h> + +#include <assert.h> +#include <err.h> +#include <fcntl.h> +#include <gelf.h> +#include <libelf.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "core.h" + +#define PROCSTAT_CORE_MAGIC 0x012DADB8 +struct procstat_core +{ + int pc_magic; + int pc_fd; + Elf *pc_elf; + GElf_Ehdr pc_ehdr; + GElf_Phdr pc_phdr; +}; + +static const struct psc_type_info { + unsigned int n_type; + int structsize; +} psc_type_info[PSC_TYPE_MAX] = { + [PSC_TYPE_PROC] = { + .n_type = NT_PROCSTAT_PROC, + .structsize = sizeof(struct kinfo_proc) + }, + [PSC_TYPE_FILES] = { + .n_type = NT_PROCSTAT_FILES, + .structsize = sizeof(struct kinfo_file) + }, + [PSC_TYPE_VMMAP] = { + .n_type = NT_PROCSTAT_VMMAP, + .structsize = sizeof(struct kinfo_vmentry) + }, + [PSC_TYPE_GROUPS] = { + .n_type = NT_PROCSTAT_GROUPS, + .structsize = sizeof(gid_t) + }, + [PSC_TYPE_UMASK] = { + .n_type = NT_PROCSTAT_UMASK, + .structsize = sizeof(u_short) + }, + [PSC_TYPE_RLIMIT] = { + .n_type = NT_PROCSTAT_RLIMIT, + .structsize = sizeof(struct rlimit) * RLIM_NLIMITS + }, + [PSC_TYPE_OSREL] = { + .n_type = NT_PROCSTAT_OSREL, + .structsize = sizeof(int) + }, + [PSC_TYPE_PSSTRINGS] = { + .n_type = NT_PROCSTAT_PSSTRINGS, + .structsize = sizeof(vm_offset_t) + }, + [PSC_TYPE_ARGV] = { + .n_type = NT_PROCSTAT_PSSTRINGS, + .structsize = sizeof(vm_offset_t) + }, + [PSC_TYPE_ENVV] = { + .n_type = NT_PROCSTAT_PSSTRINGS, + .structsize = sizeof(vm_offset_t) + }, + [PSC_TYPE_AUXV] = { + .n_type = NT_PROCSTAT_AUXV, + .structsize = sizeof(Elf_Auxinfo) + }, + [PSC_TYPE_PTLWPINFO] = { + .n_type = NT_PTLWPINFO, + .structsize = sizeof(struct ptrace_lwpinfo) + }, + [PSC_TYPE_KQUEUES] = { + .n_type = NT_PROCSTAT_KQUEUES, + .structsize = sizeof(struct kinfo_knote) + }, +}; + +static bool core_offset(struct procstat_core *core, off_t offset); +static bool core_read(struct procstat_core *core, void *buf, size_t len); +static ssize_t core_read_mem(struct procstat_core *core, void *buf, + size_t len, vm_offset_t addr, bool readall); +static void *get_args(struct procstat_core *core, vm_offset_t psstrings, + enum psc_type type, void *buf, size_t *lenp); + +struct procstat_core * +procstat_core_open(const char *filename) +{ + struct procstat_core *core; + Elf *e; + GElf_Ehdr ehdr; + GElf_Phdr phdr; + size_t nph; + int fd, i; + + if (elf_version(EV_CURRENT) == EV_NONE) { + warnx("ELF library too old"); + return (NULL); + } + fd = open(filename, O_RDONLY, 0); + if (fd == -1) { + warn("open(%s)", filename); + return (NULL); + } + e = elf_begin(fd, ELF_C_READ, NULL); + if (e == NULL) { + warnx("elf_begin: %s", elf_errmsg(-1)); + goto fail; + } + if (elf_kind(e) != ELF_K_ELF) { + warnx("%s is not an ELF object", filename); + goto fail; + } + if (gelf_getehdr(e, &ehdr) == NULL) { + warnx("gelf_getehdr: %s", elf_errmsg(-1)); + goto fail; + } + if (ehdr.e_type != ET_CORE) { + warnx("%s is not a CORE file", filename); + goto fail; + } + if (elf_getphdrnum(e, &nph) == -1) { + warnx("program headers not found"); + goto fail; + } + for (i = 0; i < ehdr.e_phnum; i++) { + if (gelf_getphdr(e, i, &phdr) != &phdr) { + warnx("gelf_getphdr: %s", elf_errmsg(-1)); + goto fail; + } + if (phdr.p_type == PT_NOTE) + break; + } + if (i == ehdr.e_phnum) { + warnx("NOTE program header not found"); + goto fail; + } + core = malloc(sizeof(struct procstat_core)); + if (core == NULL) { + warn("malloc(%zu)", sizeof(struct procstat_core)); + goto fail; + } + core->pc_magic = PROCSTAT_CORE_MAGIC; + core->pc_fd = fd; + core->pc_elf = e; + core->pc_ehdr = ehdr; + core->pc_phdr = phdr; + + return (core); +fail: + if (e != NULL) + elf_end(e); + close(fd); + + return (NULL); +} + +void +procstat_core_close(struct procstat_core *core) +{ + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + elf_end(core->pc_elf); + close(core->pc_fd); + free(core); +} + +void * +procstat_core_get(struct procstat_core *core, enum psc_type type, void *buf, + size_t *lenp) +{ + Elf_Note nhdr; + off_t offset, eoffset; + vm_offset_t psstrings; + void *freebuf; + size_t len, curlen; + int cstructsize; + char nbuf[8]; + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + if (type >= PSC_TYPE_MAX) { + warnx("unknown core stat type: %d", type); + return (NULL); + } + + offset = core->pc_phdr.p_offset; + eoffset = offset + core->pc_phdr.p_filesz; + curlen = 0; + + while (offset < eoffset) { + if (!core_offset(core, offset)) + return (NULL); + if (!core_read(core, &nhdr, sizeof(nhdr))) + return (NULL); + + offset += sizeof(nhdr) + + roundup2(nhdr.n_namesz, sizeof(Elf32_Size)) + + roundup2(nhdr.n_descsz, sizeof(Elf32_Size)); + + if (nhdr.n_namesz == 0 && nhdr.n_descsz == 0) + break; + if (nhdr.n_type != psc_type_info[type].n_type) + continue; + if (nhdr.n_namesz != 8) + continue; + if (!core_read(core, nbuf, sizeof(nbuf))) + return (NULL); + if (strcmp(nbuf, "FreeBSD") != 0) + continue; + if (nhdr.n_descsz < sizeof(cstructsize)) { + warnx("corrupted core file"); + return (NULL); + } + if (!core_read(core, &cstructsize, sizeof(cstructsize))) + return (NULL); + if (cstructsize != psc_type_info[type].structsize) { + warnx("version mismatch"); + return (NULL); + } + len = nhdr.n_descsz - sizeof(cstructsize); + if (len == 0) + return (NULL); + if (buf != NULL) { + len = MIN(len, *lenp); + freebuf = NULL; + } else { + freebuf = buf = malloc(len); + if (buf == NULL) { + warn("malloc(%zu)", len); + return (NULL); + } + } + if (!core_read(core, (char *)buf + curlen, len)) { + free(freebuf); + return (NULL); + } + if (type == PSC_TYPE_ARGV || type == PSC_TYPE_ENVV) { + if (len < sizeof(psstrings)) { + free(freebuf); + return (NULL); + } + psstrings = *(vm_offset_t *)buf; + if (freebuf == NULL) + len = *lenp; + else + buf = NULL; + free(freebuf); + buf = get_args(core, psstrings, type, buf, &len); + } else if (type == PSC_TYPE_PTLWPINFO) { + *lenp -= len; + curlen += len; + continue; + } + *lenp = len; + return (buf); + } + + if (curlen != 0) { + *lenp = curlen; + return (buf); + } + + return (NULL); +} + +static bool +core_offset(struct procstat_core *core, off_t offset) +{ + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + if (lseek(core->pc_fd, offset, SEEK_SET) == -1) { + warn("core: lseek(%jd)", (intmax_t)offset); + return (false); + } + return (true); +} + +static bool +core_read(struct procstat_core *core, void *buf, size_t len) +{ + ssize_t n; + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + n = read(core->pc_fd, buf, len); + if (n == -1) { + warn("core: read"); + return (false); + } + if (n < (ssize_t)len) { + warnx("core: short read"); + return (false); + } + return (true); +} + +static ssize_t +core_read_mem(struct procstat_core *core, void *buf, size_t len, + vm_offset_t addr, bool readall) +{ + GElf_Phdr phdr; + off_t offset; + int i; + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + for (i = 0; i < core->pc_ehdr.e_phnum; i++) { + if (gelf_getphdr(core->pc_elf, i, &phdr) != &phdr) { + warnx("gelf_getphdr: %s", elf_errmsg(-1)); + return (-1); + } + if (phdr.p_type != PT_LOAD) + continue; + if (addr < phdr.p_vaddr || addr > phdr.p_vaddr + phdr.p_memsz) + continue; + offset = phdr.p_offset + (addr - phdr.p_vaddr); + if ((phdr.p_vaddr + phdr.p_memsz) - addr < len) { + if (readall) { + warnx("format error: " + "attempt to read out of segment"); + return (-1); + } + len = (phdr.p_vaddr + phdr.p_memsz) - addr; + } + if (!core_offset(core, offset)) + return (-1); + if (!core_read(core, buf, len)) + return (-1); + return (len); + } + warnx("format error: address %ju not found", (uintmax_t)addr); + return (-1); +} + +#define ARGS_CHUNK_SZ 256 /* Chunk size (bytes) for get_args operations. */ + +static void * +get_args(struct procstat_core *core, vm_offset_t psstrings, enum psc_type type, + void *args, size_t *lenp) +{ + struct ps_strings pss; + void *freeargs; + vm_offset_t addr; + char **argv, *p; + size_t chunksz, done, len, nchr, size; + ssize_t n; + u_int i, nstr; + + assert(type == PSC_TYPE_ARGV || type == PSC_TYPE_ENVV); + + if (core_read_mem(core, &pss, sizeof(pss), psstrings, true) == -1) + return (NULL); + if (type == PSC_TYPE_ARGV) { + addr = (vm_offset_t)pss.ps_argvstr; + nstr = pss.ps_nargvstr; + } else /* type == PSC_TYPE_ENVV */ { + addr = (vm_offset_t)pss.ps_envstr; + nstr = pss.ps_nenvstr; + } + if (addr == 0 || nstr == 0) + return (NULL); + if (nstr > ARG_MAX) { + warnx("format error"); + return (NULL); + } + size = nstr * sizeof(char *); + argv = malloc(size); + if (argv == NULL) { + warn("malloc(%zu)", size); + return (NULL); + } + done = 0; + freeargs = NULL; + if (core_read_mem(core, argv, size, addr, true) == -1) + goto fail; + if (args != NULL) { + nchr = MIN(ARG_MAX, *lenp); + } else { + nchr = ARG_MAX; + freeargs = args = malloc(nchr); + if (args == NULL) { + warn("malloc(%zu)", nchr); + goto fail; + } + } + p = args; + for (i = 0; ; i++) { + if (i == nstr) + goto done; + /* + * The program may have scribbled into its argv array, e.g. to + * remove some arguments. If that has happened, break out + * before trying to read from NULL. + */ + if (argv[i] == NULL) + goto done; + for (addr = (vm_offset_t)argv[i]; ; addr += chunksz) { + chunksz = MIN(ARGS_CHUNK_SZ, nchr - 1 - done); + if (chunksz <= 0) + goto done; + n = core_read_mem(core, p, chunksz, addr, false); + if (n == -1) + goto fail; + len = strnlen(p, chunksz); + p += len; + done += len; + if (len != chunksz) + break; + } + *p++ = '\0'; + done++; + } +fail: + free(freeargs); + args = NULL; +done: + *lenp = done; + free(argv); + return (args); +} + +int +procstat_core_note_count(struct procstat_core *core, enum psc_type type) +{ + Elf_Note nhdr; + off_t offset, eoffset; + int cstructsize; + char nbuf[8]; + int n; + + if (type >= PSC_TYPE_MAX) { + warnx("unknown core stat type: %d", type); + return (0); + } + + offset = core->pc_phdr.p_offset; + eoffset = offset + core->pc_phdr.p_filesz; + + for (n = 0; offset < eoffset; n++) { + if (!core_offset(core, offset)) + return (0); + if (!core_read(core, &nhdr, sizeof(nhdr))) + return (0); + + offset += sizeof(nhdr) + + roundup2(nhdr.n_namesz, sizeof(Elf32_Size)) + + roundup2(nhdr.n_descsz, sizeof(Elf32_Size)); + + if (nhdr.n_namesz == 0 && nhdr.n_descsz == 0) + break; + if (nhdr.n_type != psc_type_info[type].n_type) + continue; + if (nhdr.n_namesz != 8) + continue; + if (!core_read(core, nbuf, sizeof(nbuf))) + return (0); + if (strcmp(nbuf, "FreeBSD") != 0) + continue; + if (nhdr.n_descsz < sizeof(cstructsize)) { + warnx("corrupted core file"); + return (0); + } + if (!core_read(core, &cstructsize, sizeof(cstructsize))) + return (0); + if (cstructsize != psc_type_info[type].structsize) { + warnx("version mismatch"); + return (0); + } + if (nhdr.n_descsz - sizeof(cstructsize) == 0) + return (0); + } + + return (n); +} |