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#include "system.h"
#include "core.h"
int shell(struct Process *proc, char *args) {
struct Process selfproc;
pid_t pid;
pid_t status;
status = 0;
errno = 0;
if (!proc) {
// provide our own proc structure
// albeit not accessible to the user
memset(&selfproc, 0, sizeof(selfproc));
proc = &selfproc;
}
if (!args) {
proc->returncode = -1;
return -1;
}
FILE *tp = NULL;
char *t_name;
t_name = xmkstemp(&tp, "w");
if (!t_name || !tp) {
return -1;
}
fprintf(tp, "#!/bin/bash\n%s\n", args);
fflush(tp);
fclose(tp);
// Set the script's permissions so that only the calling user can use it
// This should help prevent eavesdropping if keys are applied in plain-text
// somewhere.
chmod(t_name, 0700);
pid = fork();
if (pid == -1) {
fprintf(stderr, "fork failed\n");
exit(1);
} else if (pid == 0) {
FILE *fp_out = NULL;
FILE *fp_err = NULL;
if (strlen(proc->f_stdout)) {
fp_out = freopen(proc->f_stdout, "w+", stdout);
if (!fp_out) {
fprintf(stderr, "Unable to redirect stdout to %s: %s\n", proc->f_stdout, strerror(errno));
exit(1);
}
}
if (strlen(proc->f_stderr)) {
if (!proc->redirect_stderr) {
fp_err = freopen(proc->f_stderr, "w+", stderr);
if (!fp_err) {
fprintf(stderr, "Unable to redirect stderr to %s: %s\n", proc->f_stdout, strerror(errno));
exit(1);
}
}
}
if (proc->redirect_stderr) {
if (fp_err) {
fclose(fp_err);
fclose(stderr);
}
if (dup2(fileno(stdout), fileno(stderr)) < 0) {
fprintf(stderr, "Unable to redirect stderr to stdout: %s\n", strerror(errno));
exit(1);
}
}
return execl("/bin/bash", "bash", "--norc", t_name, (char *) NULL);
} else {
if (waitpid(pid, &status, WUNTRACED) > 0) {
if (WIFEXITED(status) && WEXITSTATUS(status)) {
if (WEXITSTATUS(status) == 127) {
fprintf(stderr, "execv failed\n");
}
} else if (WIFSIGNALED(status)) {
fprintf(stderr, "signal received: %d\n", WIFSIGNALED(status));
}
} else {
fprintf(stderr, "waitpid() failed\n");
}
}
if (!access(t_name, F_OK)) {
remove(t_name);
}
proc->returncode = status;
guard_free(t_name);
return WEXITSTATUS(status);
}
int shell_safe(struct Process *proc, char *args) {
FILE *fp;
char buf[1024] = {0};
int result;
char *invalid_ch = strpbrk(args, STASIS_SHELL_SAFE_RESTRICT);
if (invalid_ch) {
args = NULL;
}
result = shell(proc, args);
if (strlen(proc->f_stdout)) {
fp = fopen(proc->f_stdout, "r");
if (fp) {
while (fgets(buf, sizeof(buf) - 1, fp)) {
fprintf(stdout, "%s", buf);
buf[0] = '\0';
}
fclose(fp);
fp = NULL;
}
}
if (strlen(proc->f_stderr)) {
fp = fopen(proc->f_stderr, "r");
if (fp) {
while (fgets(buf, sizeof(buf) - 1, fp)) {
fprintf(stderr, "%s", buf);
buf[0] = '\0';
}
fclose(fp);
fp = NULL;
}
}
return result;
}
char *shell_output(const char *command, int *status) {
const size_t initial_size = STASIS_BUFSIZ;
size_t current_size = initial_size;
char *result = NULL;
char line[STASIS_BUFSIZ];
FILE *pp;
errno = 0;
*status = 0;
pp = popen(command, "r");
if (!pp) {
*status = -1;
return NULL;
}
if (errno) {
*status = 1;
}
result = calloc(initial_size, sizeof(result));
memset(line, 0, sizeof(line));
while (fread(line, sizeof(char), sizeof(line) - 1, pp) != 0) {
size_t result_len = strlen(result);
size_t need_realloc = (result_len + strlen(line)) > current_size;
if (need_realloc) {
current_size += initial_size;
char *tmp = realloc(result, sizeof(*result) * current_size);
if (!tmp) {
return NULL;
} else if (tmp != result) {
result = tmp;
}
}
strcat(result, line);
memset(line, 0, sizeof(line));
}
*status = pclose(pp);
return result;
}
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