/* misc.cpp - Store all functions that are unable to be catagorized clearly */ #include <sys/types.h> #include <sys/wait.h> #include <sys/prctl.h> #include <sys/sysmacros.h> #include <string.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <pwd.h> #include <unistd.h> #include <syscall.h> #include <random> #include <string> #include <utils.hpp> using namespace std; int fork_dont_care() { int pid = xfork(); if (pid) { waitpid(pid, nullptr, 0); return pid; } else if ((pid = xfork())) { exit(0); } return 0; } int fork_no_zombie() { int pid = xfork(); if (pid) return pid; // Unblock all signals sigset_t block_set; sigfillset(&block_set); pthread_sigmask(SIG_UNBLOCK, &block_set, nullptr); prctl(PR_SET_PDEATHSIG, SIGTERM); if (getppid() == 1) exit(1); return 0; } constexpr char ALPHANUM[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; static bool seeded = false; static std::mt19937 gen; static std::uniform_int_distribution<int> dist(0, sizeof(ALPHANUM) - 2); int gen_rand_str(char *buf, int len, bool varlen) { if (!seeded) { if (access("/dev/urandom", F_OK) != 0) mknod("/dev/urandom", 0600 | S_IFCHR, makedev(1, 9)); int fd = xopen("/dev/urandom", O_RDONLY | O_CLOEXEC); unsigned seed; xxread(fd, &seed, sizeof(seed)); gen.seed(seed); close(fd); seeded = true; } if (varlen) { std::uniform_int_distribution<int> len_dist(len / 2, len); len = len_dist(gen); } for (int i = 0; i < len - 1; ++i) buf[i] = ALPHANUM[dist(gen)]; buf[len - 1] = '\0'; return len - 1; } int strend(const char *s1, const char *s2) { size_t l1 = strlen(s1); size_t l2 = strlen(s2); return strcmp(s1 + l1 - l2, s2); } int exec_command(exec_t &exec) { int pipefd[] = {-1, -1}; int outfd = -1; if (exec.fd == -1) { if (xpipe2(pipefd, O_CLOEXEC) == -1) return -1; outfd = pipefd[1]; } else if (exec.fd >= 0) { outfd = exec.fd; } int pid = exec.fork(); if (pid < 0) { close(pipefd[0]); close(pipefd[1]); return -1; } else if (pid) { if (exec.fd == -1) { exec.fd = pipefd[0]; close(pipefd[1]); } return pid; } if (outfd >= 0) { xdup2(outfd, STDOUT_FILENO); if (exec.err) xdup2(outfd, STDERR_FILENO); close(outfd); } // Call the pre-exec callback if (exec.pre_exec) exec.pre_exec(); execve(exec.argv[0], (char **) exec.argv, environ); PLOGE("execve %s", exec.argv[0]); exit(-1); } int exec_command_sync(exec_t &exec) { int pid = exec_command(exec); if (pid < 0) return -1; int status; waitpid(pid, &status, 0); return WEXITSTATUS(status); } int new_daemon_thread(thread_entry entry, void *arg, const pthread_attr_t *attr) { pthread_t thread; int ret = xpthread_create(&thread, attr, entry, arg); if (ret == 0) pthread_detach(thread); return ret; } static void *proxy_routine(void *fp) { auto fn = reinterpret_cast<std::function<void()>*>(fp); (*fn)(); delete fn; return nullptr; } int new_daemon_thread(std::function<void()> &&entry) { return new_daemon_thread(proxy_routine, new std::function<void()>(std::move(entry))); } static char *argv0; static size_t name_len; void init_argv0(int argc, char **argv) { argv0 = argv[0]; name_len = (argv[argc - 1] - argv[0]) + strlen(argv[argc - 1]) + 1; } void set_nice_name(const char *name) { memset(argv0, 0, name_len); strlcpy(argv0, name, name_len); prctl(PR_SET_NAME, name); } bool ends_with(const std::string_view &s1, const std::string_view &s2) { unsigned l1 = s1.length(); unsigned l2 = s2.length(); return l1 < l2 ? false : s1.compare(l1 - l2, l2, s2) == 0; } /* * Bionic's atoi runs through strtol(). * Use our own implementation for faster conversion. */ int parse_int(const char *s) { int val = 0; char c; while ((c = *(s++))) { if (c > '9' || c < '0') return -1; val = val * 10 + c - '0'; } return val; } uint32_t binary_gcd(uint32_t u, uint32_t v) { if (u == 0) return v; if (v == 0) return u; auto shift = __builtin_ctz(u | v); u >>= __builtin_ctz(u); do { v >>= __builtin_ctz(v); if (u > v) { auto t = v; v = u; u = t; } v -= u; } while (v != 0); return u << shift; } int switch_mnt_ns(int pid) { char mnt[32]; snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid); if (access(mnt, R_OK) == -1) return 1; // Maybe process died.. int fd, ret; fd = xopen(mnt, O_RDONLY); if (fd < 0) return 1; // Switch to its namespace ret = xsetns(fd, 0); close(fd); return ret; } string &replace_all(string &str, string_view from, string_view to) { size_t pos = 0; while((pos = str.find(from, pos)) != string::npos) { str.replace(pos, from.length(), to); pos += to.length(); } return str; }