| 1 | #include <unistd.h> |
| 2 | #include <sys/types.h> |
| 3 | #include <sys/stat.h> |
| 4 | #include <fcntl.h> |
| 5 | #include <string.h> |
| 6 | #include <linux/string.h> |
| 7 | #include <errno.h> |
| 8 | #include <sys/wait.h> |
| 9 | #include "subcmd-util.h" |
| 10 | #include "run-command.h" |
| 11 | #include "exec-cmd.h" |
| 12 | |
| 13 | #define STRERR_BUFSIZE 128 |
| 14 | |
| 15 | static inline void close_pair(int fd[2]) |
| 16 | { |
| 17 | close(fd[0]); |
| 18 | close(fd[1]); |
| 19 | } |
| 20 | |
| 21 | static inline void dup_devnull(int to) |
| 22 | { |
| 23 | int fd = open("/dev/null", O_RDWR); |
| 24 | dup2(fd, to); |
| 25 | close(fd); |
| 26 | } |
| 27 | |
| 28 | int start_command(struct child_process *cmd) |
| 29 | { |
| 30 | int need_in, need_out, need_err; |
| 31 | int fdin[2], fdout[2], fderr[2]; |
| 32 | char sbuf[STRERR_BUFSIZE]; |
| 33 | |
| 34 | /* |
| 35 | * In case of errors we must keep the promise to close FDs |
| 36 | * that have been passed in via ->in and ->out. |
| 37 | */ |
| 38 | |
| 39 | need_in = !cmd->no_stdin && cmd->in < 0; |
| 40 | if (need_in) { |
| 41 | if (pipe(fdin) < 0) { |
| 42 | if (cmd->out > 0) |
| 43 | close(cmd->out); |
| 44 | return -ERR_RUN_COMMAND_PIPE; |
| 45 | } |
| 46 | cmd->in = fdin[1]; |
| 47 | } |
| 48 | |
| 49 | need_out = !cmd->no_stdout |
| 50 | && !cmd->stdout_to_stderr |
| 51 | && cmd->out < 0; |
| 52 | if (need_out) { |
| 53 | if (pipe(fdout) < 0) { |
| 54 | if (need_in) |
| 55 | close_pair(fdin); |
| 56 | else if (cmd->in) |
| 57 | close(cmd->in); |
| 58 | return -ERR_RUN_COMMAND_PIPE; |
| 59 | } |
| 60 | cmd->out = fdout[0]; |
| 61 | } |
| 62 | |
| 63 | need_err = !cmd->no_stderr && cmd->err < 0; |
| 64 | if (need_err) { |
| 65 | if (pipe(fderr) < 0) { |
| 66 | if (need_in) |
| 67 | close_pair(fdin); |
| 68 | else if (cmd->in) |
| 69 | close(cmd->in); |
| 70 | if (need_out) |
| 71 | close_pair(fdout); |
| 72 | else if (cmd->out) |
| 73 | close(cmd->out); |
| 74 | return -ERR_RUN_COMMAND_PIPE; |
| 75 | } |
| 76 | cmd->err = fderr[0]; |
| 77 | } |
| 78 | |
| 79 | fflush(NULL); |
| 80 | cmd->pid = fork(); |
| 81 | if (!cmd->pid) { |
| 82 | if (cmd->no_stdin) |
| 83 | dup_devnull(0); |
| 84 | else if (need_in) { |
| 85 | dup2(fdin[0], 0); |
| 86 | close_pair(fdin); |
| 87 | } else if (cmd->in) { |
| 88 | dup2(cmd->in, 0); |
| 89 | close(cmd->in); |
| 90 | } |
| 91 | |
| 92 | if (cmd->no_stderr) |
| 93 | dup_devnull(2); |
| 94 | else if (need_err) { |
| 95 | dup2(fderr[1], 2); |
| 96 | close_pair(fderr); |
| 97 | } |
| 98 | |
| 99 | if (cmd->no_stdout) |
| 100 | dup_devnull(1); |
| 101 | else if (cmd->stdout_to_stderr) |
| 102 | dup2(2, 1); |
| 103 | else if (need_out) { |
| 104 | dup2(fdout[1], 1); |
| 105 | close_pair(fdout); |
| 106 | } else if (cmd->out > 1) { |
| 107 | dup2(cmd->out, 1); |
| 108 | close(cmd->out); |
| 109 | } |
| 110 | |
| 111 | if (cmd->dir && chdir(cmd->dir)) |
| 112 | die("exec %s: cd to %s failed (%s)", cmd->argv[0], |
| 113 | cmd->dir, str_error_r(errno, sbuf, sizeof(sbuf))); |
| 114 | if (cmd->env) { |
| 115 | for (; *cmd->env; cmd->env++) { |
| 116 | if (strchr(*cmd->env, '=')) |
| 117 | putenv((char*)*cmd->env); |
| 118 | else |
| 119 | unsetenv(*cmd->env); |
| 120 | } |
| 121 | } |
| 122 | if (cmd->preexec_cb) |
| 123 | cmd->preexec_cb(); |
| 124 | if (cmd->exec_cmd) { |
| 125 | execv_cmd(cmd->argv); |
| 126 | } else { |
| 127 | execvp(cmd->argv[0], (char *const*) cmd->argv); |
| 128 | } |
| 129 | exit(127); |
| 130 | } |
| 131 | |
| 132 | if (cmd->pid < 0) { |
| 133 | int err = errno; |
| 134 | if (need_in) |
| 135 | close_pair(fdin); |
| 136 | else if (cmd->in) |
| 137 | close(cmd->in); |
| 138 | if (need_out) |
| 139 | close_pair(fdout); |
| 140 | else if (cmd->out) |
| 141 | close(cmd->out); |
| 142 | if (need_err) |
| 143 | close_pair(fderr); |
| 144 | return err == ENOENT ? |
| 145 | -ERR_RUN_COMMAND_EXEC : |
| 146 | -ERR_RUN_COMMAND_FORK; |
| 147 | } |
| 148 | |
| 149 | if (need_in) |
| 150 | close(fdin[0]); |
| 151 | else if (cmd->in) |
| 152 | close(cmd->in); |
| 153 | |
| 154 | if (need_out) |
| 155 | close(fdout[1]); |
| 156 | else if (cmd->out) |
| 157 | close(cmd->out); |
| 158 | |
| 159 | if (need_err) |
| 160 | close(fderr[1]); |
| 161 | |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | static int wait_or_whine(pid_t pid) |
| 166 | { |
| 167 | char sbuf[STRERR_BUFSIZE]; |
| 168 | |
| 169 | for (;;) { |
| 170 | int status, code; |
| 171 | pid_t waiting = waitpid(pid, &status, 0); |
| 172 | |
| 173 | if (waiting < 0) { |
| 174 | if (errno == EINTR) |
| 175 | continue; |
| 176 | fprintf(stderr, " Error: waitpid failed (%s)", |
| 177 | str_error_r(errno, sbuf, sizeof(sbuf))); |
| 178 | return -ERR_RUN_COMMAND_WAITPID; |
| 179 | } |
| 180 | if (waiting != pid) |
| 181 | return -ERR_RUN_COMMAND_WAITPID_WRONG_PID; |
| 182 | if (WIFSIGNALED(status)) |
| 183 | return -ERR_RUN_COMMAND_WAITPID_SIGNAL; |
| 184 | |
| 185 | if (!WIFEXITED(status)) |
| 186 | return -ERR_RUN_COMMAND_WAITPID_NOEXIT; |
| 187 | code = WEXITSTATUS(status); |
| 188 | switch (code) { |
| 189 | case 127: |
| 190 | return -ERR_RUN_COMMAND_EXEC; |
| 191 | case 0: |
| 192 | return 0; |
| 193 | default: |
| 194 | return -code; |
| 195 | } |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | int finish_command(struct child_process *cmd) |
| 200 | { |
| 201 | return wait_or_whine(cmd->pid); |
| 202 | } |
| 203 | |
| 204 | int run_command(struct child_process *cmd) |
| 205 | { |
| 206 | int code = start_command(cmd); |
| 207 | if (code) |
| 208 | return code; |
| 209 | return finish_command(cmd); |
| 210 | } |
| 211 | |
| 212 | static void prepare_run_command_v_opt(struct child_process *cmd, |
| 213 | const char **argv, |
| 214 | int opt) |
| 215 | { |
| 216 | memset(cmd, 0, sizeof(*cmd)); |
| 217 | cmd->argv = argv; |
| 218 | cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0; |
| 219 | cmd->exec_cmd = opt & RUN_EXEC_CMD ? 1 : 0; |
| 220 | cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0; |
| 221 | } |
| 222 | |
| 223 | int run_command_v_opt(const char **argv, int opt) |
| 224 | { |
| 225 | struct child_process cmd; |
| 226 | prepare_run_command_v_opt(&cmd, argv, opt); |
| 227 | return run_command(&cmd); |
| 228 | } |