141 lines
2.7 KiB
C++
141 lines
2.7 KiB
C++
#include <BAN/Assert.h>
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#include <ctype.h>
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#include <errno.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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static FILE* s_pwent_fp = nullptr;
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static passwd s_pwent_struct;
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static bool open_pwent()
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{
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if (s_pwent_fp)
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return true;
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s_pwent_fp = fopen("/etc/passwd", "r");
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return s_pwent_fp;
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}
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static void clear_pwent(passwd& passwd)
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{
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if (passwd.pw_name)
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free(passwd.pw_name);
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passwd.pw_name = nullptr;
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if (passwd.pw_dir)
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free(passwd.pw_dir);
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passwd.pw_dir = nullptr;
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if (passwd.pw_shell)
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free(passwd.pw_shell);
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passwd.pw_shell = nullptr;
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}
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void endpwent(void)
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{
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if (!s_pwent_fp)
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return;
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fclose(s_pwent_fp);
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s_pwent_fp = nullptr;
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clear_pwent(s_pwent_struct);
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}
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struct passwd* getpwent(void)
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{
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if (!s_pwent_fp)
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if (!open_pwent())
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return nullptr;
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clear_pwent(s_pwent_struct);
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static char buffer[4096];
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if (!fgets(buffer, sizeof(buffer), s_pwent_fp))
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return nullptr;
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size_t buffer_len = strlen(buffer);
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ASSERT(buffer[buffer_len - 1] == '\n');
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buffer[buffer_len - 1] = '\0';
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buffer_len--;
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const char* ptr = buffer;
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for (int i = 0; i < 7; i++)
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{
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char* end = strchr(ptr, ':');
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ASSERT((i < 6) ? end != nullptr : end == nullptr);
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if (!end)
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end = buffer + buffer_len;
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*end = '\0';
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const size_t field_len = end - ptr;
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switch (i)
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{
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case 0:
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s_pwent_struct.pw_name = (char*)malloc(field_len + 1);
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if (!s_pwent_struct.pw_name)
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return nullptr;
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strcpy(s_pwent_struct.pw_name, ptr);
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break;
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case 1:
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break;
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case 2:
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ASSERT(1 <= field_len && field_len <= 9);
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for (size_t j = 0; j < field_len; j++)
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ASSERT(isdigit(ptr[j]));
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s_pwent_struct.pw_uid = atoi(ptr);
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break;
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case 3:
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ASSERT(1 <= field_len && field_len <= 9);
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for (size_t j = 0; j < field_len; j++)
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ASSERT(isdigit(ptr[j]));
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s_pwent_struct.pw_uid = atoi(ptr);
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break;
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case 4:
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break;
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case 5:
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s_pwent_struct.pw_dir = (char*)malloc(field_len + 1);
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if (!s_pwent_struct.pw_dir)
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return nullptr;
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strcpy(s_pwent_struct.pw_dir, ptr);
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break;
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case 6:
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s_pwent_struct.pw_shell = (char*)malloc(field_len + 1);
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if (!s_pwent_struct.pw_shell)
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return nullptr;
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strcpy(s_pwent_struct.pw_shell, ptr);
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break;
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}
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ptr = end + 1;
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}
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return &s_pwent_struct;
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}
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struct passwd* getpwnam(const char* name)
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{
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passwd* pwd;
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setpwent();
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while ((pwd = getpwent()))
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if (strcmp(pwd->pw_name, name) == 0)
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return pwd;
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return nullptr;
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}
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struct passwd* getpwuid(uid_t uid)
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{
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passwd* pwd;
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setpwent();
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while ((pwd = getpwent()))
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if (pwd->pw_uid == uid)
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return pwd;
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return nullptr;
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}
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void setpwent(void)
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{
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if (!s_pwent_fp)
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return;
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fseek(s_pwent_fp, 0, SEEK_SET);
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}
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