masqmail-0.2

annotate src/peopen.c @ 170:0f0e4e7cd762

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added misc/list-versions This script helps to check if the versions numbers in the project are the same as the one for the release. This script is motivated by the 0.2.27 release in which masqmail introduces itself as being version 0.2.26.
author meillo@marmaro.de
date Mon, 19 Jul 2010 14:01:13 +0200
parents 3654c502a4df
children
rev   line source
meillo@0 1 /* This a snippet I found in sourceforge. I just changed the identing
meillo@29 2 style to my own and deleted the main function. -- oku
meillo@29 3 The functions destroy_argv() and create_argv() were added by oku.
meillo@29 4 */
meillo@0 5
meillo@0 6 #include <errno.h>
meillo@0 7 #include <stdio.h>
meillo@0 8 #include <stdlib.h>
meillo@0 9 #include <unistd.h>
meillo@0 10 #include <string.h>
meillo@0 11 #include <sys/types.h>
meillo@15 12 #include <sysexits.h>
meillo@0 13
meillo@0 14 #include "peopen.h"
meillo@0 15 #include "masqmail.h"
meillo@0 16
meillo@10 17 static void
meillo@10 18 destroy_argv(char **arr)
meillo@0 19 {
meillo@10 20 char *p = arr[0];
meillo@10 21 int i = 0;
meillo@0 22
meillo@10 23 while (p) {
meillo@10 24 free(p);
meillo@10 25 p = arr[i++];
meillo@10 26 }
meillo@10 27 free(arr);
meillo@0 28 }
meillo@0 29
meillo@10 30 static char**
meillo@10 31 create_argv(const char *cmd, int count)
meillo@0 32 {
meillo@10 33 char buf[strlen(cmd) + 1];
meillo@10 34 char **arr, *q;
meillo@10 35 const char *p;
meillo@10 36 int i = 0;
meillo@0 37
meillo@27 38 arr = (char **) g_malloc(sizeof(char *) * count);
meillo@0 39
meillo@10 40 p = cmd;
meillo@10 41 while (*p && i < (count - 1)) {
meillo@10 42 while (*p && isspace(*p))
meillo@10 43 p++;
meillo@10 44 q = buf;
meillo@10 45 while (*p && !isspace(*p))
meillo@10 46 *q++ = *p++;
meillo@15 47 *q = '\0';
meillo@10 48 arr[i++] = strdup(buf);
meillo@10 49 while (*p && isspace(*p))
meillo@10 50 p++;
meillo@10 51 }
meillo@10 52 arr[i] = NULL;
meillo@10 53
meillo@10 54 return arr;
meillo@0 55 }
meillo@0 56
meillo@10 57 FILE*
meillo@10 58 peidopen(const char *command, const char *type, char *const envp[], int *ret_pid, uid_t uid, gid_t gid)
meillo@0 59 {
meillo@10 60 enum { Read, Write } mode;
meillo@10 61 int pipe_fd[2];
meillo@10 62 pid_t pid;
meillo@0 63
meillo@10 64 if (command == NULL || type == NULL) {
meillo@10 65 errno = EINVAL;
meillo@10 66 return NULL;
meillo@10 67 }
meillo@0 68
meillo@10 69 if (strcmp(type, "r")) {
meillo@10 70 if (strcmp(type, "w")) {
meillo@10 71 errno = EINVAL;
meillo@10 72 return NULL;
meillo@10 73 } else
meillo@10 74 mode = Write;
meillo@10 75 } else
meillo@10 76 mode = Read;
meillo@0 77
meillo@10 78 if (pipe(pipe_fd) == -1)
meillo@10 79 return NULL;
meillo@0 80
meillo@10 81 switch (pid = fork()) {
meillo@10 82 case 0: /* child thread */
meillo@0 83
meillo@10 84 {
meillo@10 85 int i, max_fd = sysconf(_SC_OPEN_MAX);
meillo@10 86
meillo@10 87 if (max_fd <= 0)
meillo@10 88 max_fd = 64;
meillo@10 89 for (i = 0; i < max_fd; i++)
meillo@10 90 if ((i != pipe_fd[0]) && (i != pipe_fd[1]))
meillo@10 91 close(i);
meillo@10 92 }
meillo@10 93 if (close(pipe_fd[mode == Read ? 0 : 1]) != -1 &&
meillo@10 94 dup2(pipe_fd[mode == Read ? 1 : 0],
meillo@10 95 mode == Read ? STDOUT_FILENO : STDIN_FILENO) != -1) {
meillo@10 96 // char *argv [] = { "/bin/sh", "-c", (char*) command, NULL };
meillo@10 97 char **argv = create_argv(command, 10);
meillo@10 98 int ret;
meillo@10 99
meillo@10 100 if (uid != (uid_t) - 1) {
meillo@10 101 if ((ret = seteuid(0)) != 0) {
meillo@10 102 exit(EX_NOPERM);
meillo@10 103 }
meillo@10 104 }
meillo@10 105 if (gid != (gid_t) - 1) {
meillo@10 106 if ((ret = setgid(gid)) != 0) {
meillo@10 107 exit(EX_NOPERM);
meillo@10 108 }
meillo@10 109 }
meillo@10 110 if (uid != (uid_t) - 1) {
meillo@10 111 if ((ret = setuid(uid)) != 0) {
meillo@10 112 exit(EX_NOPERM);
meillo@10 113 }
meillo@10 114 }
meillo@10 115 execve(*argv, argv, envp);
meillo@10 116 }
meillo@10 117
meillo@10 118 _exit(errno);
meillo@10 119
meillo@10 120 default: /* parent thread */
meillo@10 121 *ret_pid = pid;
meillo@10 122 close(pipe_fd[mode == Read ? 1 : 0]);
meillo@10 123 return fdopen(pipe_fd[mode == Read ? 0 : 1], type);
meillo@10 124
meillo@10 125 case -1:
meillo@10 126 close(pipe_fd[0]);
meillo@10 127 close(pipe_fd[1]);
meillo@10 128 return NULL;
meillo@0 129 }
meillo@0 130 }
meillo@0 131
meillo@10 132 FILE*
meillo@10 133 peopen(const char *command, const char *type, char *const envp[], int *ret_pid)
meillo@0 134 {
meillo@10 135 return peidopen(command, type, envp, ret_pid, -1, -1);
meillo@0 136 }