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-rw-r--r--proc-region-rw.c225
1 files changed, 0 insertions, 225 deletions
diff --git a/proc-region-rw.c b/proc-region-rw.c
deleted file mode 100644
index f25fe2b..0000000
--- a/proc-region-rw.c
+++ /dev/null
@@ -1,225 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdbool.h>
-#include <string.h>
-#include <sys/ptrace.h>
-#include <sys/wait.h>
-#include <err.h>
-
-// It's recommended to `setcap cap_sys_ptrace=eip proc-region-rw` to run this tool without sudo
-
-struct context {
- void *buf;
-
- struct {
- size_t offset, len;
- bool has_offset, has_len;
-
- struct {
- FILE *src;
- size_t size;
- } wm; // write/map
-
- enum {
- MODE_MAP,
- MODE_WRITE,
- MODE_READ
- } mode;
- } op;
-
- struct {
- FILE *mem;
- pid_t pid;
- } proc;
-};
-
-static void
-usage(const char *argv0)
-{
- fprintf(stderr, "usage: %s pid map file [offset] [len] < regions\n"
- " %s pid write file [offset] [len] < regions\n"
- " %s pid read [offset] [len] < regions\n"
- " regions must be in /proc/<pid>/maps format", argv0, argv0, argv0);
- exit(EXIT_FAILURE);
-}
-
-static void
-context_init(struct context *ctx, size_t argc, const char *argv[])
-{
- if (argc < 3)
- usage(argv[0]);
-
- size_t arg = 1;
- *ctx = (struct context){0};
- ctx->proc.pid = strtoull(argv[arg++], NULL, 10);
-
- {
- bool m = false, w = false, r = false;
- const char *mode = argv[arg++];
- if (!(m = !strcmp(mode, "map")) && !(w = !strcmp(mode, "write")) && !(r = !strcmp(mode, "read")))
- errx(EXIT_FAILURE, "mode must be write or read");
-
- ctx->op.mode = (m ? MODE_MAP : (w ? MODE_WRITE : MODE_READ));
- }
-
- const char *wmname = NULL;
- if (ctx->op.mode == MODE_MAP || ctx->op.mode == MODE_WRITE) {
- if (argc < arg + 1)
- usage(argv[0]);
-
- wmname = argv[arg++];
- }
-
- if (argc >= arg + 1) {
- ctx->op.offset = strtoull(argv[arg++], NULL, 10);
- ctx->op.has_offset = true;
- }
-
- if (argc >= arg + 1) {
- ctx->op.len = strtoull(argv[arg++], NULL, 10);
- ctx->op.has_len = true;
- }
-
- if (wmname) {
- if (!(ctx->op.wm.src = fopen(wmname, "rb")))
- err(EXIT_FAILURE, "fopen(%s)", wmname);
-
- if (fseek(ctx->op.wm.src, 0, SEEK_END) != 0)
- err(EXIT_FAILURE, "fseek");
-
- ctx->op.wm.size = ftell(ctx->op.wm.src);
- }
-
- char path[128];
- snprintf(path, sizeof(path), "/proc/%u/mem", ctx->proc.pid);
- if (!(ctx->proc.mem = fopen(path, "w+b")))
- err(EXIT_FAILURE, "fopen(%s)", path);
-}
-
-static void
-context_release(struct context *ctx)
-{
- if (ctx->op.wm.src)
- fclose(ctx->op.wm.src);
-
- fclose(ctx->proc.mem);
- free(ctx->buf);
- *ctx = (struct context){0};
-}
-
-static void
-for_each_line_in_file(FILE *f, void (*cb)(const char *line, void *data), void *data)
-{
- char *buffer = NULL;
- size_t step = 1024, allocated = 0, written = 0, read = 0;
- do {
- if (written + read >= allocated && !(buffer = realloc(buffer, (allocated += step) + 1)))
- err(EXIT_FAILURE, "realloc");
- buffer[(written += read)] = 0;
- size_t ate = 0;
- for (char *line = buffer, *nl; (nl = strchr(line, '\n')); line = nl + 1) {
- *nl = 0;
- cb(line, data);
- ate += nl + 1 - line;
- }
- memmove(buffer, buffer + ate, (written = written - ate));
- } while ((read = fread(buffer + written, 1, allocated - written, f)));
- free(buffer);
-}
-
-static void
-region_cb(const char *line, void *data)
-{
- struct context *ctx = data;
- unsigned long start, end, region_offset;
- if (sscanf(line, "%lx-%lx %*s %lx", &start, &end, &region_offset) < 3) {
- warnx("failed to parse mapping:\n%s", line);
- return;
- }
-
- warnx("%s", line);
- start += ctx->op.offset;
-
- if (start > end) {
- warnx("write offset %lx is out of bounds", start);
- return;
- }
-
- region_offset = (ctx->op.mode == MODE_MAP ? region_offset : 0);
-
- // requested write/read
- const size_t rlen = (ctx->op.has_len ? ctx->op.len : (ctx->op.mode == MODE_READ ? end - start : ctx->op.wm.size));
-
- // actual write/read
- const size_t len = (rlen > end - start ? end - start : rlen);
-
- if (!len)
- return;
-
- if (!(ctx->buf = realloc(ctx->buf, len)))
- err(EXIT_FAILURE, "realloc");
-
- clearerr(ctx->proc.mem);
- if (ctx->op.mode == MODE_MAP || ctx->op.mode == MODE_WRITE) {
- if (fseek(ctx->op.wm.src, region_offset, SEEK_SET) != 0)
- err(EXIT_FAILURE, "fseek");
-
- const size_t rd = fread(ctx->buf, 1, len, ctx->op.wm.src);
-
- if (fseek(ctx->proc.mem, start, SEEK_SET) != 0)
- err(EXIT_FAILURE, "fseek");
-
- const size_t wd = fwrite(ctx->buf, 1, rd, ctx->proc.mem);
-
- if (ferror(ctx->proc.mem)) {
- warn("fread(/proc/%u/mem)", ctx->proc.pid);
- return;
- }
-
- if (ctx->op.mode == MODE_WRITE) {
- if (rlen > wd) {
- warnx("wrote %lu bytes (%lu bytes truncated) to offset 0x%lx", wd, rlen - wd, start);
- } else {
- warnx("wrote %lu bytes to offset 0x%lx", wd, start);
- }
- } else {
- if (rlen > wd) {
- warnx("mapped %lu bytes (%lu bytes truncated) from offset 0x%lx to offset 0x%lx", wd, rlen - wd, region_offset, start);
- } else {
- warnx("mapped %lu bytes from offset 0x%lx to offset 0x%lx", wd, region_offset, start);
- }
- }
- } else {
- if (fseek(ctx->proc.mem, start, SEEK_SET) != 0)
- err(EXIT_FAILURE, "fseek");
-
- const size_t rd = fread(ctx->buf, 1, len, ctx->proc.mem);
-
- if (ferror(ctx->proc.mem))
- warn("fread(/proc/%u/mem)", ctx->proc.pid);
-
- if (fwrite(ctx->buf, 1, rd, stdout) != rd)
- err(EXIT_FAILURE, "fwrite");
- }
-}
-
-int
-main(int argc, const char *argv[])
-{
- struct context ctx;
- context_init(&ctx, argc, argv);
-
- if (ptrace(PTRACE_ATTACH, ctx.proc.pid, NULL, NULL) == -1L)
- err(EXIT_FAILURE, "ptrace(PTRACE_ATTACH, %u, NULL, NULL)", ctx.proc.pid);
-
- {
- int status;
- if (waitpid(ctx.proc.pid, &status, 0) == -1 || !WIFSTOPPED(status))
- err(EXIT_FAILURE, "waitpid");
- }
-
- for_each_line_in_file(stdin, region_cb, &ctx);
- ptrace(PTRACE_DETACH, ctx.proc.pid, 1, 0);
- context_release(&ctx);
- return EXIT_SUCCESS;
-}