diff options
Diffstat (limited to 'kernel/fs/procfs.c')
| -rw-r--r-- | kernel/fs/procfs.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/kernel/fs/procfs.c b/kernel/fs/procfs.c new file mode 100644 index 0000000..f6a4fef --- /dev/null +++ b/kernel/fs/procfs.c @@ -0,0 +1,185 @@ +#include <errno.h> +#include <fs/procfs.h> +#include <lib/sb.h> +#include <lib/sv.h> +#include <stdio.h> + +#define ARRAY_LENGTH(a) (sizeof(a) / sizeof((a)[0])) + +vfs_inode_t *procfs_open(const char *p); + +void procfs_close(vfs_fd_t *fd) { + return; +} + +void process_close(vfs_fd_t *fd) { + process_t *p = fd->inode->internal_object; + if (!p) { + return; + } + process_remove_reference(p); +} + +int procfs_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) { + struct sb builder; + sb_init_buffer(&builder, buffer, len); + + size_t read_amount = 0; + + process_t *p = ready_queue; + for (; p; p = p->next) { + struct dirent entry; + entry.d_ino = p->pid; + ksnprintf(entry.d_name, sizeof(entry.d_name), "%u", p->pid); + + if (read_amount >= offset) { + if (0 == sb_append_buffer(&builder, (u8 *)&entry, sizeof(entry))) { + break; + } + } + read_amount += sizeof(struct dirent); + } + return sv_length(SB_TO_SV(builder)); +} + +#define PROCESS_ROOT 0 +#define PROCESS_SIGNAL 1 +#define PROCESS_NAME 2 + +struct dirent process_entries[] = { + { + .d_ino = PROCESS_ROOT, + .d_name = "", + }, + { + .d_ino = PROCESS_ROOT, + .d_name = ".", + }, + { + .d_ino = PROCESS_SIGNAL, + .d_name = "signal", + }, + { + .d_ino = PROCESS_NAME, + .d_name = "name", + }, +}; + +int process_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) { + process_t *p = fd->inode->internal_object; + + struct sb builder; + sb_init_buffer(&builder, buffer, len); + + int id = fd->inode->inode_num; + if (PROCESS_ROOT == id) { + size_t read_amount = 0; + for (size_t i = 0; i < ARRAY_LENGTH(process_entries); i++) { + if (0 == strlen(process_entries[i].d_name)) { + continue; + } + if (read_amount >= offset) { + if (0 == sb_append_buffer(&builder, (u8 *)&process_entries[i], + sizeof(struct dirent))) { + break; + } + } + read_amount += sizeof(struct dirent); + } + return sv_length(SB_TO_SV(builder)); + } + if (PROCESS_NAME == id) { + struct sv program_name = C_TO_SV(p->program_name); + sv_take(program_name, &program_name, offset); + sb_append_sv(&builder, program_name); + return sv_length(SB_TO_SV(builder)); + } + return -EBADF; +} + +int process_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) { + (void)offset; + process_t *p = fd->inode->internal_object; + + int id = fd->inode->inode_num; + if (PROCESS_SIGNAL == id) { + struct sv t = sv_init(buffer, len); + int got_num; + u64 signal = sv_parse_unsigned_number(t, NULL, &got_num); + if (got_num) { + signal_process(p, signal); + } + // TODO: Add the ability to write "SIGTERM", "SIGKILL" etc without + // writing the number. + return 0; + } + return -EBADF; +} + +vfs_inode_t *open_process(u64 pid, int id) { + process_t *process = NULL; + process_t *t = ready_queue; + for (; t; t = t->next) { + if ((u64)t->pid == pid) { + process = t; + break; + } + } + if (!process) { + return NULL; + } + + vfs_inode_t *inode = vfs_create_inode( + id /*inode_num*/, 0 /*type*/, 0 /*has_data*/, 0 /*can_write*/, + 0 /*is_open*/, 0, process /*internal_object*/, 0 /*file_size*/, + procfs_open, NULL /*create_file*/, process_read, process_write, + process_close, NULL /*create_directory*/, NULL /*get_vm_object*/, + NULL /*truncate*/, NULL /*stat*/, NULL /*send_signal*/, NULL /*connect*/); + if (!inode) { + return NULL; + } + process->reference_count++; + return inode; +} + +vfs_inode_t *procfs_open(const char *p) { + struct sv path = C_TO_SV(p); + + if ((sv_try_eat(path, &path, C_TO_SV("/")) && 0 == sv_length(path)) || + 0 == sv_length(path)) { + return vfs_create_inode( + 0 /*inode_num*/, 0 /*type*/, 0 /*has_data*/, 0 /*can_write*/, + 0 /*is_open*/, 0, NULL /*internal_object*/, 0 /*file_size*/, + procfs_open, NULL /*create_file*/, procfs_read, NULL /* write */, + procfs_close, NULL /*create_directory*/, NULL /*get_vm_object*/, + NULL /*truncate*/, NULL /*stat*/, NULL /*send_signal*/, + NULL /*connect*/); + } + + int got_num; + u64 pid = sv_parse_unsigned_number(path, &path, &got_num); + if (!got_num) { + return NULL; + } + + // NOTE: There should only be one '/' since the previous vfs_open will + // call vfs_clean_path first. This is a bit hacky and that code might + // change later and as a result introduce bugs here. + sv_try_eat(path, &path, C_TO_SV("/")); + for (size_t i = 0; i < ARRAY_LENGTH(process_entries); i++) { + if (sv_eq(path, C_TO_SV(process_entries[i].d_name))) { + return open_process(pid, process_entries[i].d_ino); + } + } + return NULL; +} + +vfs_inode_t *procfs_mount(void) { + vfs_inode_t *inode = vfs_create_inode( + 0 /*inode_num*/, 0 /*type*/, 0 /*has_data*/, 0 /*can_write*/, + 0 /*is_open*/, 0, NULL /*internal_object*/, 0 /*file_size*/, procfs_open, + NULL /*create_file*/, procfs_read, NULL /* write */, procfs_close, + NULL /*create_directory*/, NULL /*get_vm_object*/, NULL /*truncate*/, + NULL /*stat*/, NULL /*send_signal*/, NULL /*connect*/); + return inode; +} |